Vitamins & Supplements · Supplement formula

Pre-Workout Supplements: What They Contain, Ingredient by Ingredient

Multi-ingredient pre-workout supplements · also called Pre-workout, MIPS, pre-entreno, suplemento preentrenamiento

Pre-workout supplements are powders, drinks and capsules sold to be taken before exercise. Most are a blend of about 18 ingredients, led by caffeine, beta-alanine, citrulline, tyrosine, taurine and creatine. Small trials of some blends show better results on some single-workout tests, but the blend as a whole is not proven, and the best evidence is for single ingredients. Main cautions are caffeine side effects, sleep, the heart and hidden ingredients.

General information, not medical advice. Last substantive update October 26, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

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About Pre-Workout Supplements: What They Contain, Ingredient by Ingredient

A pre-workout is a blend sold to be taken before exercise. Most are built around caffeine. Evidence for the whole blend is thin, evidence for caffeine, beta-alanine and creatine is stronger but belongs to those ingredients, and several cautions apply.

What a pre-workout is and what is usually inside

A pre-workout is a powder, drink or capsule sold to be taken before exercise. There is no single recipe. A 2019 survey of the 100 top-selling products found about 18 ingredients per product on average.

The most common were beta-alanine (87% of products), caffeine (86%), citrulline (71%), tyrosine (63%), taurine (51%) and creatine (49%). Caffeine, creatine, beta-alanine, taurine and citrulline each have their own page, linked under Related. They are sold to gym-goers and athletes for energy, focus and training.

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Reading the label

Supplement Facts panels list a serving size and each ingredient. A proprietary blend lists the ingredients together with one total weight, so you cannot see the amount of each. In the 2019 survey, 44.3% of all listed ingredients sat in such blends.

Compare amounts per serving. Caffeine may also come from other ingredients such as guarana, and the FDA notes that most energy drinks list total caffeine from all sources on the label.

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Food versus the product

Caffeine also comes from everyday drinks and foods such as coffee, tea and chocolate, per the FDA page. Amounts of the other ingredients in foods were not read from USDA or NIH sources, so none are stated here.

No trial comparing food sources with a pre-workout product was read.

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What the research shows

Whole blends: small trials of one serving found better results on some tests, such as repetitions or power, but not on others, and each used a different formula. One trial found caffeine alone did better than a blend.

Single ingredients: caffeine, beta-alanine and creatine have the strongest evidence, but beta-alanine and creatine work through weeks of daily use. Citrulline and taurine show small, uncertain effects. Tyrosine did not help endurance. The evidence for single ingredients was not added up as proof for a blend.

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At a glance

Traditional uses history, not proof

A modern sports-supplement category with no traditional use
Sold to athletes and gym-goers for energy, focus and training

Studied for research

Strength, power and repetitions in one workout, low certainty
Caffeine on its own for exercise performance, moderate certainty
Beta-alanine and creatine on their own, moderate certainty
Citrulline and taurine, low certainty
Tyrosine for endurance, evidence against
Heart effects, insufficient and conflicting evidence

Main compounds

Caffeine
Beta-alanine
Citrulline
Tyrosine
Taurine
Creatine

Common forms

Powder
Ready-to-drink
Capsules
Stimulant and stimulant-free versions

Research links: 2019 survey: common ingredients of the 100 top-selling pre-workouts · 2018 review: safety and performance of multi-ingredient pre-workouts · 2021 position stand: caffeine and exercise performance · 2023 review: case reports with synephrine pre-workouts · FDA: how much caffeine is too much · Research Library · Genes & Biomarkers Library

What it is and its history

Accepted scientific name: Pre-workout supplements (multi-ingredient pre-workout supplements, MIPS)
Common names: Pre-workout (English); Pre-workout supplement (English); Multi-ingredient pre-workout supplement (MIPS) (English); Pre-entreno (Spanish); Suplemento preentrenamiento (Spanish)
Family or group: A blend-type sports supplement. The 2019 label survey found about 18 listed ingredients per product on average, most often beta-alanine, caffeine, citrulline, tyrosine, taurine and creatine.
Harvest and processing: Sold as powders, ready-to-drink cans, capsules and chewables. How they are made was not read from a source.
Look-alikes and adulterants: Name: Energy drinks and shots; Note: Caffeine drinks with taurine and vitamins; covered by an ISSN position stand. Has its own page.; Name: Caffeine alone; Note: The main active ingredient of most pre-workouts. Has its own page.; Name: Creatine products; Note: A single ingredient with long research. Has its own page.; Name: Fat burner blends; Note: Stimulant blends sold for weight loss, sometimes with the same stimulants. Has its own page.
Sustainability and conservation: Not assessed.

What is inside, and how it may work

What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.

Main compounds

Compound	Family	Where it is concentrated	Activity studied	Level of evidence
Caffeine	stimulant	Listed in 86% of 100 top-selling products; average 254 mg where shown (2019 survey)	The main ergogenic ingredient in most products; see the Benefits tab. ^{14 11}	Human data
Beta-alanine	amino acid	Listed in 87%; average 2.0 g where shown (2019 survey)	Raises muscle carnosine after weeks of daily intake; causes harmless tingling. ^{14 24}	Human data
Citrulline	amino acid	Listed in 71%; average 4.0 g where shown (2019 survey)	Sold for blood flow and tiredness; small, uncertain performance effect. ^{14 26}	Human data
Tyrosine	amino acid	Listed in 63%; average 348 mg where shown (2019 survey)	No benefit for endurance in a pooled analysis. ^{14 23}	Human data
Taurine	amino acid-like compound	Listed in 51%; average 1.3 g where shown (2019 survey)	Small gain in pooled single-dose analysis, low certainty. ^{14 5}	Human data
Creatine	amino-acid derivative	Listed in 49%; average 2.1 g where shown (2019 survey)	Raises muscle creatine; supports high-intensity exercise. ^{14 17}	Human data

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
Muscle carnosine (acid buffer)	Not specified in the abstract	Four weeks of daily beta-alanine raised muscle carnosine, an acid buffer inside muscle. ²⁴	Human data
Muscle creatine stores	Not specified in the abstract	Creatine raised the creatine stored in muscle, which may explain better high-intensity performance. ¹⁷	Human data
Nitric oxide and ammonia handling (citrulline)	Not specified	Described in the citrulline review as the thought behind its use; the same review found no endurance benefit. ¹²	Theoretical
Stimulation of the nervous system (caffeine)	Not specified in the abstracts	Caffeine improves alertness and attention; responses and side effects vary with genetics and habitual use per the position stand. ¹¹	Human data
Liver cell toxicity in a lab model	Glutathione, DNA damage markers	One pre-workout was toxic to liver cells and lowered glutathione in a lab test; not tested in people. ⁴	In vitro

Absorption, metabolism and elimination

Absorption: Not covered. Trials gave blends 10 to 60 minutes before exercise (Gonzalez: 10 minutes; Douligeris: 30; Beyer: 60), and the caffeine position stand says the most common timing is 60 minutes.
Distribution: Not found.
Metabolism: Not covered in the abstracts read.
Elimination: Not covered.
Bioavailability: Not compared across products in the sources read.

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Isolated compounds versus whole extracts

A pre-workout is a mix of isolated ingredients. Where the research is good it is for one ingredient at a time, often over weeks. The mix, the amounts in it and the form were rarely tested together. Coffee and tea bring caffeine in food and drink, but no food-versus-product trial was read.

Nutritional composition

No USDA or NIH amounts of these ingredients in foods were read, so none are stated. Typical label amounts come from the 2019 survey and describe what products listed, not what anyone should take.

11benefits and uses looked at

29studies and sources checked

Moderate certaintybest evidence rating found

4lab markers tracked in trials

3 moderate certainty5 low certainty1 very low certainty1 not enough evidence1 evidence against

What was looked at

The 11 benefits and uses checked for Pre-Workout Supplements: What They Contain, Ingredient by Ingredient, each with how strong the evidence is. Tap one to open it.

Strength, power and repetitions in one workout (whole product tested)Low certainty
Blend compared with caffeine aloneVery low certainty
Caffeine on its own (the main ingredient)Moderate certainty
Beta-alanine on its ownModerate certainty
Creatine on its ownModerate certainty
Citrulline on its ownLow certainty
Taurine on its own and with caffeineLow certainty
Tyrosine on its ownEvidence against
Longer-term training results with a blendLow certainty
Focus, mood and reaction timeLow certainty
Heart and blood pressure markersNot enough evidence

Lab markers tracked in the studies

Repetitions and power in a resistance workoutCycling sprint power (Wingate test)Pooled exercise performance scores (single ingredients)Time to exhaustion and time trial

What is Pre-Workout Supplements: What They Contain, Ingredient by Ingredient good for?

The studied uses and how strong the human evidence is for each. Trials of whole blends are tiny and use different formulas. Evidence for single ingredients does not prove that the blend works.

Strength, power and repetitions in one workout (whole product)Low certaintyFive small trials (8 to 30 people) of commercial blends found more repetitions or power on some tests and no change on others. Formulas differed, and one trial was paid for by the maker. Blend compared with caffeine aloneVery low certaintyIn one trial of 15 men, caffeine alone gave more bench press repetitions than a blend. One small trial only. Caffeine on its ownModerate certaintyExperts say caffeine improves many but not all types of exercise, with the most consistent benefit for endurance. This is evidence for caffeine, not the blend. Beta-alanine on its ownModerate certaintyBenefit shows after weeks of daily use for efforts of 1 to 4 minutes; tingling is the known side effect. One pre-workout serving cannot give this build-up. Creatine on its ownModerate certaintyRaises muscle creatine and supports high-intensity exercise; reported safe in healthy people in studies up to five years. Citrulline on its ownLow certaintyA 30-trial analysis found a very small gain with wide uncertainty; a 9-trial analysis found no endurance benefit. Taurine on its own and with caffeineLow certaintyA 23-trial analysis found a small gain graded low to very low; caffeine plus taurine may help anaerobic effort and reaction time more than either alone. Tyrosine on its ownEvidence againstPooled analysis of 8 studies found no benefit for endurance. Longer-term training resultsLow certaintyA 2018 review says blends with strength training may add lean mass; other long-term results are unclear. Focus, mood and reaction timeLow certaintyMixed: faster reaction time in one trial, no change in felt energy or focus in another. Heart and blood pressure markersNot enough evidenceA 2025 review of 24 studies found conflicting adverse and protective signals.

Benefits, one by one

Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.

Strength, power and repetitions in one workout (whole product tested)

Low certainty

Several small trials gave a commercial pre-workout once, before a test, and compared it with placebo. Most found more repetitions or more power on some tests, and no change on others. Each trial used a different formula, so the results cannot be added up into one claim about all pre-workouts.

6 studiesEach trial tested a different commercial formula. Amounts studied are…

Studies, doses and limits

What the trials found

Gonzalez 2011 (8 men): more squat and bench repetitions (26.3 vs 23.5) and higher power. Kaczka 2020 (23 men): higher strength and power in cycling and knee tests. Beyer 2024 (20 people): more bench repetitions (96.9 vs 89.5) and better reaction time and peak power; the funder's chief scientific officer is an author. Drwal 2024 (12 untrained men): better peak and mean cycling power but not total work. Douligeris 2023 (30 basketball players): better jump, agility and repeated sprints, but no change in sprinting or aerobic tests. A 2018 review says acute use may help muscular endurance and mood, with mixed results for force and power.

Results

Positive on some tests in most trials; not positive on every test, and not the same test in each trial.

Effect sizes as reported

Examples: reps 26.3 vs 23.5 (Gonzalez); reps 96.9 vs 89.5 (Beyer); repeated-sprint average +18.3% vs -2.2% (Douligeris). Effect sizes were not given in most abstracts.

Why this rating

Low because the trials are tiny (8 to 30 people), test one serving once, use different formulas, and one was paid for by the maker.

Form and dose studied

Each trial tested a different commercial formula. Amounts studied are in the studies table.

Who was studied

Mostly resistance-trained or athletic young adults; one trial in untrained men.

Limits

Single sessions only. Brand formulas differ. No trial tested the full 18-ingredient kind of blend that the label survey found on average.

Why researchers looked

Pre-workouts are sold to improve one training session, so trials test one serving before a workout.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

No serious side effects were reported in the abstracts read, but trials were short. See the Safety tab.

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Blend compared with caffeine alone

Very low certainty

Most pre-workouts are mostly caffeine. The one trial that compared a blend with the same amount of caffeine alone found the caffeine did at least as well, and better for bench press repetitions. It is a small trial, so this is a warning sign rather than a settled answer.

1 studiesOne blend and caffeine alone; amounts are in the studies table.

Studies, doses and limits

What the trials found

Kruszewski 2022: 15 resistance-trained men did a bench press endurance test after a blend (beta-alanine, citrulline malate, arginine alpha-ketoglutarate, taurine, tyrosine and caffeine) and after anhydrous caffeine alone. Repetitions were higher after caffeine alone. Mood and arousal scales did not differ. The authors concluded the blend was less effective and less cost-effective.

Results

Against an added benefit from the extra ingredients, in one small trial.

Effect sizes as reported

Caffeine alone gave more bench press repetitions than the blend; size not given in the abstract.

Why this rating

Very low because only one trial of 15 men was found, single-blind, with one test.

Form and dose studied

One blend and caffeine alone; amounts are in the studies table.

Who was studied

15 resistance-trained men.

Limits

One study, one exercise, one blend.

Why researchers looked

A blend only makes sense if the extra ingredients add something beyond its caffeine.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

No safety outcome was reported in the abstract.

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Caffeine on its own (the main ingredient)

Moderate certainty

Caffeine is the best-supported ingredient. The 2021 sports-nutrition position stand says it improves many but not all kinds of exercise, with small-to-moderate gains, and its most consistent benefit is for endurance. This is evidence for caffeine alone, not for the whole product.

1 studiesCaffeine amounts in trials are in the studies table.

Studies, doses and limits

What the trials found

ISSN 2021 position stand: acute benefit in many but not all studies for muscular endurance, speed, strength, sprinting and jumping; most consistent for aerobic endurance; helps attention and alertness in most people; energy drinks and caffeine pre-workouts enhanced anaerobic and aerobic performance. It also says responses and side effects (sleep, anxiety) vary between people, and that very high amounts bring more side effects.

Results

Small-to-moderate benefit overall.

Effect sizes as reported

Qualitative in the abstract.

Why this rating

Moderate because it rests on a large body of trials summarised by experts, but the statement is a consensus rather than a new pooled analysis, and several authors have ties to supplement companies.

Form and dose studied

Caffeine amounts in trials are in the studies table.

Who was studied

Healthy adults, trained and untrained.

Limits

Consensus statement; effects differ by person and by exercise type.

Why researchers looked

Caffeine is in about 86% of top-selling pre-workouts, so most of any benefit probably comes from it.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not covered here. The position stand covers effects, not how caffeine works.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab for sleep, anxiety and heart effects.

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Beta-alanine on its own

Moderate certainty

Beta-alanine helps when taken daily for weeks, not in one serving before a workout. Its known side effect is harmless tingling. A pre-workout with beta-alanine in it cannot give this benefit in one session.

2 studiesStudied as daily intake over weeks; see the studies table.

Studies, doses and limits

What the trials found

ISSN 2015 position stand: daily use for at least 2 to 4 weeks improved performance, most clearly in efforts lasting 1 to 4 minutes; tingling (paraesthesia) was the only reported side effect and was reduced by smaller divided amounts or sustained-release forms; more research is needed on strength and on efforts over 25 minutes. The 2019 label survey found the average beta-alanine amount per serving was below the authors' effective amount.

Results

Positive for 1 to 4 minute efforts after weeks of daily use.

Effect sizes as reported

Qualitative in the abstract.

Why this rating

Moderate because several trials support it, but it is an expert statement and the benefit depends on weeks of daily use.

Form and dose studied

Studied as daily intake over weeks; see the studies table.

Who was studied

Healthy adults.

Limits

Does not describe a one-serving pre-workout use.

Why researchers looked

It is in about 87% of top-selling pre-workouts.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Human biochemical

Four weeks of daily beta-alanine raised muscle carnosine, which buffers acid inside muscle (ISSN 2015).

A proposed mechanism does not show that the effect happens in people.

Tingling is common and was not harmful in the studies the position stand summarised.

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Creatine on its own

Moderate certainty

Creatine is one of the best-studied sports supplements. Experts report it raises muscle creatine and supports high-intensity exercise and training gains, and that it was safe in healthy people in studies lasting up to five years. Like beta-alanine, its benefit builds over time and is not a one-serving effect.

2 studiesSee the studies table.

Studies, doses and limits

What the trials found

ISSN 2017 position stand: consistently increases muscle creatine and is linked to better high-intensity performance and training adaptations; short- and long-term use was reported safe and well tolerated in healthy people.

Results

Positive for high-intensity exercise and training gains.

Effect sizes as reported

Qualitative in the abstract.

Why this rating

Moderate because the evidence base is large, but the source is an expert position stand and this abstract gives no pooled numbers.

Form and dose studied

See the studies table.

Who was studied

Healthy adults and several patient groups.

Limits

Does not tell us whether the creatine amount inside a blend is enough.

Why researchers looked

About half of top-selling pre-workouts list creatine.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Human biochemical

It reliably raises the creatine stored in muscle (ISSN 2017).

A proposed mechanism does not show that the effect happens in people.

Safety statements in the abstract are for creatine alone.

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Citrulline on its own

Low certainty

A 2026 pooled analysis of 30 trials found a very small gain in exercise performance with citrulline malate, with wide uncertainty. A separate pooled analysis of nine trials found no benefit for steady endurance exercise.

2 studiesCitrulline malate in most trials; amounts are in the studies table.

Studies, doses and limits

What the trials found

2026 meta-analysis of 30 trials (644 people): small improvement (g = 0.16), no significant change in perceived effort, certainty low to very low. 2023 meta-analysis of 9 trials (158 people): no difference in time to exhaustion or time to completion in young active adults.

Results

Very small and uncertain for overall performance; none for steady endurance.

Effect sizes as reported

g = 0.16; SMD 0.03 and -0.07 for endurance.

Why this rating

Low because the effect is tiny, trials differ and the pooled analyses graded certainty low to very low.

Form and dose studied

Citrulline malate in most trials; amounts are in the studies table.

Who was studied

Healthy, mostly young, active adults.

Limits

Wide prediction intervals; the authors ask for trials with verified supplement composition.

Why researchers looked

Citrulline is in about 71% of top-selling pre-workouts, sold for blood flow and tiredness.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Theoretical

Often said to raise nitric oxide and clear ammonia; the reviews read describe this as the thought behind it, not a shown effect.

A proposed mechanism does not show that the effect happens in people.

No safety outcome in the abstracts.

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Taurine on its own and with caffeine

Low certainty

A 2025 pooled analysis of single taurine doses found a small-to-moderate improvement in performance, but the certainty was low to very low. A network analysis of 12 studies suggests caffeine plus taurine may help anaerobic effort and reaction time more than either alone.

2 studiesCommonly 1 to 6 g in the trials of single doses; see the studies tabl…

Studies, doses and limits

What the trials found

Deng 2025 meta-analysis: 23 trials, 308 people, g = 0.25 (0.10 to 0.39), I2 = 61%, effects shrank without influential studies, GRADE low to very low. Deng 2025 network meta-analysis: caffeine plus taurine gave a credible gain over either alone in anaerobic capacity (g = 0.46) and reaction time (g = 0.75); caffeine alone gave the largest fall in perceived effort; heart rate did not differ.

Results

Small gains with low certainty.

Effect sizes as reported

g = 0.25; combined vs alone g = 0.46 and 0.75.

Why this rating

Low because both analyses are based on small studies with a lot of variation and the main one graded certainty low to very low.

Form and dose studied

Commonly 1 to 6 g in the trials of single doses; see the studies table.

Who was studied

Mostly healthy young adults, more men than women.

Limits

Heterogeneous; subgroup findings were not robust.

Why researchers looked

Taurine is in about 51% of top-selling pre-workouts.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established in the abstracts read.

A proposed mechanism does not show that the effect happens in people.

No safety outcome in the abstracts.

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Tyrosine on its own

Evidence against

For endurance, a 2023 pooled analysis of eight studies found tyrosine made no difference to time to exhaustion or time trials. Tyrosine is in about 63% of top-selling pre-workouts, mostly for focus, and its effect on strength or focus in this use was not found in the studies read.

1 studiesSee the studies table.

Studies, doses and limits

What the trials found

Solon-Junior 2023: 8 studies (10 interventions) in active people; no difference from placebo for time to exhaustion (SMD 0.02) or time trial (SMD -0.04); GRADE moderate. The abstract notes tyrosine is known for brain-function effects but its effect on endurance is debatable.

Results

No benefit for endurance.

Effect sizes as reported

SMD 0.02 and -0.04.

Why this rating

Against an endurance benefit: moderate-quality pooled evidence found none. Strength, power and focus were not covered by the study.

Form and dose studied

See the studies table.

Who was studied

Physically active adults.

Limits

Only endurance was analysed.

Why researchers looked

Tyrosine is in about 63% of top-selling pre-workouts.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

No safety outcome in the abstract.

²³

Longer-term training results with a blend

Low certainty

A 2018 review says that using a multi-ingredient pre-workout alongside a planned strength-training program may add lean mass over time. Its effects on strength, endurance and mood over months are unclear.

1 studiesVaried products.

Studies, doses and limits

What the trials found

Harty 2018 narrative review: chronic use with periodised resistance training appears to augment lean mass; long-term effects on force, endurance and mood are less clear; most safety studies lasted under eight weeks.

Results

Possible lean-mass gain; the rest unclear.

Effect sizes as reported

Not given.

Why this rating

Low because the review is a brief narrative one and the studies it summarises were short and used different products.

Form and dose studied

Varied products.

Who was studied

Active adults.

Limits

Narrative review; no pooled numbers in the abstract.

Why researchers looked

People take pre-workouts for months, but most trials last one session.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

Most safety studies lasted under eight weeks.

¹³

Focus, mood and reaction time

Low certainty

Results are mixed. One trial found faster reaction time with a pre-workout, and a review says mood may improve, but another trial found no change in how energetic or focused people felt. Caffeine likely drives most of it.

4 studiesVaried products.

Studies, doses and limits

What the trials found

Beyer 2024: reaction time better with the pre-workout (p < 0.001). Gonzalez 2011: no difference in feelings of energy, focus or fatigue. Harty 2018: acute use may improve mood. The 2021 caffeine position stand says caffeine improves attention and alertness in most people.

Results

Mixed.

Effect sizes as reported

Reaction time p < 0.001 (Beyer).

Why this rating

Low because the studies are small, measure different things and one was paid for by the maker.

Form and dose studied

Varied products.

Who was studied

Resistance-trained adults.

Limits

Feelings were self-rated and short term.

Why researchers looked

Many products promise energy and focus, so trials record how people feel and how fast they react.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab for anxiety and sleep.

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Heart and blood pressure markers

Not enough evidence

A 2025 review of 24 studies found pre-workouts linked to both possible harms and possible benefits for the heart, and called the results conflicting. No conclusion about heart safety or benefit can be drawn from it.

1 studiesVaried products.

Studies, doses and limits

What the trials found

Bella 2025 integrative review: 24 studies, effects classed as adverse or cardioprotective, with differences in amounts and populations; the authors list possible positive effects on blood pressure, triglycerides, LDL and homocysteine, and call for more studies.

Results

Conflicting.

Effect sizes as reported

Not given.

Why this rating

Insufficient because the review found conflicting results and the studies differ widely.

Form and dose studied

Varied products.

Who was studied

Active and non-active people, with and without heart disease.

Limits

Integrative review; mixed designs.

Why researchers looked

Stimulant-containing products raise questions about the heart.

Traditional use

Pre-workout products are a modern sports-supplement category, not a traditional remedy.

Proposed mechanism Not established

Not established for the blend as a whole. Ideas about how single ingredients work are described in the Science notes; they were not shown to add up in a mix.

A proposed mechanism does not show that the effect happens in people.

Case reports of heart problems are on the Safety tab.

Connections to the rest of health

How Pre-Workout Supplements: What They Contain, Ingredient by Ingredient connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.

Explore every connection: goals, body systems, organs, symptoms, genes

Kind of connection Connected to Search

A. Wellness goals

Connected to	Evidence status	Context	Studies
Peak Performance	Low certainty	Strength, power and repetitions in one workout (whole product tested): Several small trials gave a commercial pre-workout once, before a test, and compared it with placebo. Most found more repetitions or more power on some tests, and no change on others. Each trial used a different formula, so the results cannot be added up into one claim about all pre-workouts. Citrulline on its own: A 2026 pooled analysis of 30 trials found a very small gain in exercise performance with citrulline malate, with wide uncertainty. A separate pooled analysis of nine trials found no benefit for steady endurance exercise.	^{10 16 3 8 7 13 26 12 5 6}
Physical Stamina	Low certainty	Strength, power and repetitions in one workout (whole product tested): Several small trials gave a commercial pre-workout once, before a test, and compared it with placebo. Most found more repetitions or more power on some tests, and no change on others. Each trial used a different formula, so the results cannot be added up into one claim about all pre-workouts. Citrulline on its own: A 2026 pooled analysis of 30 trials found a very small gain in exercise performance with citrulline malate, with wide uncertainty. A separate pooled analysis of nine trials found no benefit for steady endurance exercise.	^{10 16 3 8 7 13 26 12 5 6}
Peak Performance	Very low certainty	Blend compared with caffeine alone: Most pre-workouts are mostly caffeine. The one trial that compared a blend with the same amount of caffeine alone found the caffeine did at least as well, and better for bench press repetitions. It is a small trial, so this is a warning sign rather than a settled answer. Tyrosine on its own: For endurance, a 2023 pooled analysis of eight studies found tyrosine made no difference to time to exhaustion or time trials. Tyrosine is in about 63% of top-selling pre-workouts, mostly for focus, and its effect on strength or focus in this use was not found in the studies read.	^{18 23}
Physical Stamina	Very low certainty	Blend compared with caffeine alone: Most pre-workouts are mostly caffeine. The one trial that compared a blend with the same amount of caffeine alone found the caffeine did at least as well, and better for bench press repetitions. It is a small trial, so this is a warning sign rather than a settled answer. Tyrosine on its own: For endurance, a 2023 pooled analysis of eight studies found tyrosine made no difference to time to exhaustion or time trials. Tyrosine is in about 63% of top-selling pre-workouts, mostly for focus, and its effect on strength or focus in this use was not found in the studies read.	^{18 23}
Peak Performance	Moderate certainty	Caffeine on its own (the main ingredient): Caffeine is the best-supported ingredient. The 2021 sports-nutrition position stand says it improves many but not all kinds of exercise, with small-to-moderate gains, and its most consistent benefit is for endurance. This is evidence for caffeine alone, not for the whole product. Beta-alanine on its own: Beta-alanine helps when taken daily for weeks, not in one serving before a workout. Its known side effect is harmless tingling. A pre-workout with beta-alanine in it cannot give this benefit in one session.	^{11 24 14 17}
Physical Stamina	Moderate certainty	Caffeine on its own (the main ingredient): Caffeine is the best-supported ingredient. The 2021 sports-nutrition position stand says it improves many but not all kinds of exercise, with small-to-moderate gains, and its most consistent benefit is for endurance. This is evidence for caffeine alone, not for the whole product. Beta-alanine on its own: Beta-alanine helps when taken daily for weeks, not in one serving before a workout. Its known side effect is harmless tingling. A pre-workout with beta-alanine in it cannot give this benefit in one session.	^{11 24 14 17}
Energy Boost	Low certainty	Focus, mood and reaction time: Results are mixed. One trial found faster reaction time with a pre-workout, and a review says mood may improve, but another trial found no change in how energetic or focused people felt. Caffeine likely drives most of it.	^{3 10 13 11}
Heart Health	Not enough evidence	Heart and blood pressure markers: A 2025 review of 24 studies found pre-workouts linked to both possible harms and possible benefits for the heart, and called the results conflicting. No conclusion about heart safety or benefit can be drawn from it.	²

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Bones Joints Muscles	Biological association	Low certainty	Studied for: Strength, power and repetitions in one workout (whole product tested) Studied for: Blend compared with caffeine alone	^{10 16 3 8 7 13 18 24 14 17}
Nervous System	Biological association	Moderate certainty	Studied for: Caffeine on its own (the main ingredient) Studied for: Taurine on its own and with caffeine	^{11 5 6 23 3 10 13}
Cardiovascular System	Biological association	Low certainty	Studied for: Citrulline on its own Studied for: Heart and blood pressure markers	^{26 12 2}

E. Health conditions

Connected to	Kind of connection	Evidence status	Context	Studies
Cardiac arrhythmia	Adverse effect or risk	Case report	Case reports link synephrine-containing pre-workouts to abnormal heart rhythm and chest pain; caffeine may have contributed. Case reports link synephrine-containing pre-workouts to abnormal heart rhythm and chest pain. Preparation or compound: Stimulant (synephrine) pre-workouts	²⁷
Poor sleep	Adverse effect or risk	Meta analysis	Caffeine shortened sleep by about 45 minutes in pooled studies. Caffeine shortened total sleep by about 45 minutes in pooled studies. Preparation or compound: Caffeine	⁹

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
Repetitions and power in a resistance workout	Biological association	Low certainty	Measured in trials: higher with most blends tested; lower than caffeine alone in one trial. A lab change is not the same as a health benefit.	^{10 3 18}
Cycling sprint power (Wingate test)	Biological association	Low certainty	Measured in trials: higher in two small trials. A lab change is not the same as a health benefit.	^{8 16}
Pooled exercise performance scores (single ingredients)	Biological association	Low certainty	Measured in trials: slightly higher, with wide uncertainty. A lab change is not the same as a health benefit.	^{26 5}
Time to exhaustion and time trial	Biological association	Moderate certainty	Measured in trials: no change. A lab change is not the same as a health benefit.	^{12 23}

K. Biological pathways

Connected to	Kind of connection	Evidence status	Context	Studies
Caffeine	Preliminary mechanism	Human	Main active ingredient; has its own page.	¹¹
Creatine	Preliminary mechanism	Human	Single-ingredient evidence; has its own page.	¹⁷

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
Caffeine	Biological association	Human	The main ergogenic ingredient in most products; see the Benefits tab.	^{14 11}
Beta-alanine	Biological association	Human	Raises muscle carnosine after weeks of daily intake; causes harmless tingling.	^{14 24}
Citrulline	Biological association	Human	Sold for blood flow and tiredness; small, uncertain performance effect.	^{14 26}
Tyrosine	Biological association	Human	No benefit for endurance in a pooled analysis.	^{14 23}
Taurine	Biological association	Human	Small gain in pooled single-dose analysis, low certainty.	^{14 5}
Creatine	Biological association	Human	Raises muscle creatine; supports high-intensity exercise.	^{14 17}

Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).

Evidence at a glance: what the research found for 11 outcomes

3Moderate certainty

5Low certainty

1Very low certainty

1Not enough evidence

1Evidence against

Each outcome below is one thing researchers measured. Certainty is how far the evidence can be trusted, not how well it works. The full studies are on the next tab.

Strength, power and repetitions in one workout (whole product tested) 6 studies Low certainty Blend compared with caffeine alone 1 study Very low certainty Caffeine on its own (the main ingredient) 1 study Moderate certainty Beta-alanine on its own 2 studies Moderate certainty Creatine on its own 2 studies Moderate certainty Citrulline on its own 2 studies Low certainty Taurine on its own and with caffeine 2 studies Low certainty Tyrosine on its own 1 study Evidence against Longer-term training results with a blend 1 study Low certainty Focus, mood and reaction time 4 studies Low certainty Heart and blood pressure markers 1 study Not enough evidence

The evidence

The research centre for Pre-Workout Supplements: What They Contain, Ingredient by Ingredient. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).

How we rate evidence

High certainty

Several well-run trials or reviews agree; further research is unlikely to change the picture much.

Moderate certainty

Good trials point the same way, but some doubt remains.

Low certainty

Small, short or inconsistent trials. The finding could change with better research.

Very low certainty

Very little or very weak human data. Treat as a possibility only.

Mixed findings

Trials or reviews disagree with each other.

Not enough evidence

Not enough human research to say either way.

Evidence against

Good research found no benefit, or found harm.

We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We read the PubMed abstract of every study cited (not full texts) and the full text of the FDA caffeine consumer update and NCCIH supplement page. NIH ODS and USADA pages could not be read and are marked unverified.

Study library: every study we checked 29

Design Research type Year from Search

Study	Design	People	Product, dose, length	Result
Altaf 2024 Crushing Muscles: A Case Study on Rhabdomyolysis, Renal Failure, and Compartment Syndrome Triggered by Pre-Workout Supplement Abuse. Cureus · PMID 38784349 · DOI	Case report	1 One 36-year-old man	Unregulated performance supplements (including a pre-workout) with exercise Oral	Severe rhabdomyolysis (muscle breakdown) with dangerous acid-base imbalance, kidney and liver injury and peripheral neuropathy, in a person using several performance products and exercising. The report cannot separate the supplement from exercise or other products. One case (Not applicable) Methods, limits and funding Outcomes: Muscle breakdown, kidney and liver injury, nerve damage Limitations: Single case; several products and heavy exercise were involved. Funding and conflicts: No competing interests. Read: abstract
Bella 2025 Pre-Workout Supplements and Their Effects on Cardiovascular Health: An Integrative Review. J Cardiovasc Dev Dis · PMID 40278171 · DOI	Integrative review	24 studies on multi-ingredient pre-workout supplements and cardiovascular outcomes (2010 to August 2024)	Multi-ingredient pre-workout supplements Oral Varied Varied · vs Placebo or none	Studies found both possible adverse and possible protective heart effects. The authors list possible gains in energy, focus, endurance and strength, and possible positive effects on blood pressure, triglycerides, LDL and homocysteine, but call results conflicting and say more studies are needed. Not applicable (narrative) (Not applicable) Methods, limits and funding Outcomes: Heart and blood vessel effects, adverse and protective Limitations: Integrative review of mixed designs; conflicting results; products and populations differ. Funding and conflicts: No conflicts declared. Read: abstract
Beyer 2024 A single dose multi-ingredient pre-workout supplement enhances upper body resistance exercise performance. Front Nutr · PMID 38321990 · DOI	Randomised crossover trial	20 20 resistance-trained adults (10 men, 10 women)	One commercial multi-ingredient pre-workout (product ingredients not listed in the abstract) Oral One serving, 1 hour before the workout (studied in the trial) Two single sessions · vs Placebo	Reaction time and bench press peak power were better with the pre-workout. Total repetitions were higher (96.9 vs 89.5, p = 0.003) and session effort rating was lower (7.6 vs 8.3). Reps 96.9 vs 89.5 (Not given in the abstract) Methods, limits and funding Outcomes: Reaction time, bench press peak power, repetitions, perceived exertion Limitations: One product, one session, 20 people. The study was funded by the product's maker, whose chief scientific officer is an author. Funding and conflicts: Industry-funded; an author is chief scientific officer of the funder. Read: abstract
Carrão Dantas 2022 Toxicogenetic assessment of a pre-workout supplement: In vitro mutagenicity, cytotoxicity, genotoxicity and glutathione determination in liver cell lines and in silico ADMET approaches. Mutat Res Genet Toxicol Environ Mutagen · PMID 35914863 · DOI	Laboratory study in vitro	One pre-workout supplement tested in bacteria and liver cell lines	One pre-workout supplement (not named here) Oral Lab concentrations 24 to 72 hours · vs Untreated cells	The product showed mutagenic and toxic responses in the lab tests, damaged DNA markers and lowered glutathione in liver cells. A computer model suggested three of its main compounds could harm the liver. Qualitative (Not applicable) Methods, limits and funding Outcomes: Mutagenicity, cell toxicity, DNA damage, glutathione Limitations: Cell and bacteria tests on one product. Results cannot show harm in people. Funding and conflicts: Not stated in the record read. Read: abstract
Deng 2025 Does One Shot Work? The Acute Impact of a Single Taurine Dose on Exercise Performance: A Meta-Analytic Review. Scand J Med Sci Sports · PMID 40852891 · DOI	Systematic review meta analysis	308 23 randomised trials (69 effect sizes), 308 people	A single dose of taurine Oral Commonly 1 to 6 g in the studies; no clear dose-response Single dose · vs Placebo	Small-to-moderate improvement (g = 0.25, 95% CI 0.10 to 0.39; I2 = 61%). Subgroup effects shrank after excluding influential studies; prediction intervals often included no effect. GRADE low to very low. g = 0.25 (0.10 to 0.39) Methods, limits and funding Outcomes: Overall exercise performance Limitations: High heterogeneity and imprecision; certainty low to very low. Funding and conflicts: Not stated in the record read. Read: abstract
Deng 2025 Caffeine and taurine: a systematic review and network meta-analysis of their individual and combined effects on physical capacity, cognitive function, and physiological markers. J Int Soc Sports Nutr · PMID 41032459 · DOI	Systematic review network meta analysis	12 studies of caffeine and taurine alone and together	Caffeine, taurine, and both together Oral Varied Mostly acute · vs Placebo, each alone	The combination showed credible gains over caffeine or taurine alone in anaerobic capacity (g = 0.46) and reaction time (g = 0.75). Caffeine gave the largest drop in perceived effort. Heart rate did not differ. Effects on endurance were variable. Anaerobic capacity g = 0.46; reaction time g = 0.75 (0.19 to 0.71; 0.29 to 1.18) Methods, limits and funding Outcomes: Physical capacity, cognition, heart rate, perceived effort, blood lactate Limitations: Only 12 studies; many outcomes with 6 to 8 studies each; Bayesian estimates. Funding and conflicts: No conflict reported. Read: abstract
Douligeris 2023 The Effect of Acute Pre-Workout Supplement Ingestion on Basketball-Specific Performance of Well-Trained Athletes. Nutrients · PMID 37242187 · DOI	Randomised controlled trial	30 30 well-trained basketball players aged 18 to 31	Pre-workout with caffeine, creatine monohydrate, beta-alanine, citrulline malate and branched-chain amino acids Oral One serving 30 minutes before tests (amounts per serving in the abstract: 200 mg caffeine, 3.3 g creatine, 3.2 g beta-alanine, 6 g citrulline malate, 5 g BCAA) Two single test days · vs Placebo	Better countermovement jump, agility and repeated-sprint test results with the supplement. No difference in sprinting, aerobic performance or blood lactate. Jump +4.3% vs +1.2%; repeated-sprint average +18.3% vs -2.2% (Not given in the abstract) Methods, limits and funding Outcomes: Jumping, sprinting, agility, repeated-sprint test, aerobic test Limitations: Small, acute, one formula; positive on some tests only. Funding and conflicts: No conflict declared. Read: abstract
Drwal 2024 Acute effects of multi-ingredient pre-workout dietary supplement on anaerobic performance in untrained men: a randomized, crossover, single blind study. BMC Sports Sci Med Rehabil · PMID 38853269 · DOI	Randomised crossover trial	12 12 young healthy untrained men	Pre-workout with beta-alanine, taurine, caffeine, L-tyrosine and cayenne pepper Oral One serving before the test (studied in the trial) Two test days · vs Placebo	Peak power (p = 0.009) and mean power (p = 0.04) were better; total work and power drop were not significantly different. Peak power ES 0.77; mean power ES 0.62 (Not given in the abstract) Methods, limits and funding Outcomes: Wingate 20-second cycling test: peak power, mean power, total work Limitations: 12 untrained men, single-blind, registered after the study was done. Funding and conflicts: No competing interests. Registration: NCT06363669 (registered after the study) Read: abstract
Gardiner 2023 The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Med Rev · PMID 36870101 · DOI	Systematic review meta analysis	24 studies of caffeine and night-time sleep	Caffeine from coffee and other sources Oral Varied Varied · vs Placebo or no caffeine	Caffeine cut total sleep time by 45 minutes and sleep efficiency by 7%, added 9 minutes to falling asleep and 12 minutes awake after sleep onset, and reduced deep sleep (-11.4 minutes). The authors calculated that a standard pre-workout serve (217.5 mg caffeine) should be taken at least 13.2 hours before bedtime to avoid shorter total sleep. Total sleep time -45 minutes (Not given in the abstract) Methods, limits and funding Outcomes: Total sleep time, sleep efficiency, time to fall asleep, deep sleep Limitations: The timing estimate is a model from pooled studies; people differ in caffeine sensitivity. Funding and conflicts: No conflicts declared. Read: abstract
Gonzalez 2011 Effect of a pre-workout energy supplement on acute multi-joint resistance exercise. J Sports Sci Med · PMID 24149870	Randomised crossover trial	8 8 resistance-trained college-age men	A pre-workout energy supplement (caffeine, taurine, glucuronolactone, creatine, beta-alanine, leucine, isoleucine, valine, glutamine, arginine) Oral One serving 10 minutes before exercise (studied in the trial) Two single sessions · vs Placebo	More repetitions with the supplement (26.3 vs 23.5, p = 0.022) and higher peak and mean power. No difference in feelings of energy, focus or fatigue. Reps 26.3 vs 23.5 (Not given in the abstract) Methods, limits and funding Outcomes: Repetitions and power in squat and bench press, feelings of energy, focus and fatigue Limitations: Only 8 men, one session. Older (2011). Funding and conflicts: Not stated in the record read. Read: abstract
Guest 2021 International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr · PMID 33388079 · DOI	Position stand	Evidence on caffeine and exercise in healthy adults	Caffeine (capsules, drinks, gum, pre-workout and energy products) Oral Varied; see the position stand Mostly single doses · vs Placebo	Caffeine acutely improves many but not all aspects of exercise performance, with small-to-moderate benefits. Aerobic endurance shows the most consistent moderate-to-large benefit. Very high doses bring more side effects. Individual differences, including effects on sleep and anxiety, relate to genetics and habitual use. Energy drinks and pre-workouts containing caffeine have been shown to enhance anaerobic and aerobic performance. Qualitative (Not applicable) Methods, limits and funding Outcomes: Strength, endurance, sprint, jumping, cognition, side effects Limitations: Expert consensus statement, not a new pooled analysis. Funding and conflicts: Several authors report ties to supplement or caffeine companies; the society receives grants from supplement companies. Read: abstract
Harnden 2023 Effects of citrulline on endurance performance in young healthy adults: a systematic review and meta-analysis. J Int Soc Sports Nutr · PMID 37155582 · DOI	Systematic review meta analysis	158 9 studies, 158 young healthy active adults	Citrulline Oral Varied (bolus or loading) Acute · vs Placebo or control	No significant difference: time to exhaustion SMD 0.03 (-0.27 to 0.33); time to completion SMD -0.07 (-0.50 to 0.15). SMD 0.03 and -0.07 (-0.27 to 0.33; -0.50 to 0.15) Methods, limits and funding Outcomes: Time to exhaustion and time to completion in steady endurance exercise Limitations: Small evidence base; healthy young adults only. Funding and conflicts: No conflict reported. Read: abstract
Harty 2018 Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review. J Int Soc Sports Nutr · PMID 30089501 · DOI	Narrative review	Studies of multi-ingredient pre-workout supplements (MIPS) in active people	Multi-ingredient pre-workout supplements Oral Varied by product Mostly short; under 8 weeks for most safety data · vs Placebo or other supplements	Acute use may improve muscular endurance and mood; results for force and power are mixed. Used with periodised resistance training, MIPS may add lean mass. Long-term effects on strength, endurance and mood are unclear. Seems relatively safe in studies under 8 weeks. Many products may hold banned substances on purpose or by contamination. Not applicable (narrative) (Not applicable) Methods, limits and funding Outcomes: Muscular endurance, force and power, mood, body composition, safety Limitations: Brief narrative review, not a systematic search. Direct comparison is often impossible because proprietary blends hide amounts. Funding and conflicts: Authors declare no competing interests; several are at a university sports-nutrition lab. Read: abstract
Jagim 2019 Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements. Nutrients · PMID 30678328 · DOI	Cross sectional product survey n/a	100 The 100 top-selling pre-workout products, ingredient labels analysed	Label contents of multi-ingredient pre-workout products Powders, drinks and capsules · vs Established amounts from earlier research	Products listed 18.4 ingredients on average (SD 9.7); 8.1 of them sat inside a proprietary blend. Most common: beta-alanine 87% (2.0 g average), caffeine 86% (254 mg), citrulline 71% (4.0 g), tyrosine 63% (348 mg), taurine 51% (1.3 g), creatine 49% (2.1 g). 44.3% of all ingredients were in blends with undisclosed amounts. Average beta-alanine per serving was below the authors' effective amount; average caffeine was near the low end of the effective range for a 70 kg adult. Descriptive percentages (Not applicable) Methods, limits and funding Outcomes: Number of ingredients, how often each appeared, listed amounts, share hidden in proprietary blends Limitations: Shows what labels say, not what is in the tub. Top sellers at one point in time; amounts were not available for blend ingredients. Funding and conflicts: No conflicts declared. Read: abstract
Jagim 2023 International society of sports nutrition position stand: energy drinks and energy shots. J Int Soc Sports Nutr · PMID 36862943 · DOI	Position stand	Evidence on energy drinks and energy shots	Energy drinks and energy shots (caffeine, taurine and other ingredients) Oral Varied Mostly single servings · vs Placebo or other drinks	Caffeine (and carbohydrate) are the main ergogenic ingredients; extra benefit from other ingredients is not established. Many ingredients and combinations have not been studied. Adolescents should use caution; products are not recommended for children aged 2 to 12, pregnancy, breastfeeding or caffeine sensitivity; people with heart, metabolic, kidney, liver or nerve disease on medicines that caffeine or stimulants could affect should talk to a doctor. Qualitative (Not applicable) Methods, limits and funding Outcomes: Performance, focus, safety in special groups Limitations: Covers energy drinks and shots; pre-workout powders overlap but are not identical. Funding and conflicts: No conflict reported. Read: abstract
Kaczka 2020 Effects of Pre-Workout Multi-Ingredient Supplement on Anaerobic Performance: Randomized Double-Blind Crossover Study. Int J Environ Res Public Health · PMID 33182295 · DOI	Randomised crossover trial	23 23 resistance-trained men	A commercial multi-ingredient pre-workout (ingredients not listed in the abstract) Oral One serving (studied in the trial) Three sessions a week apart · vs Placebo	Strength and power were higher with the supplement: for example knee extensor torque 237 vs 203 Nm (p = 0.001), Wingate mean power 8.7 vs 8.5 W/kg (p = 0.038), and 3-RM strength higher. Knee extensor torque 237.2 vs 202.6 Nm (Not given in the abstract) Methods, limits and funding Outcomes: Isokinetic strength, 3-repetition-maximum, Wingate cycling power Limitations: Short, one product, acute testing. The abstract gives no funding statement. Funding and conflicts: No conflict declared. Read: abstract
Kreider 2017 International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr · PMID 28615996 · DOI	Position stand	Evidence on creatine in athletes and patients	Creatine Oral Varied; see the position stand Short and long term (up to 5 years in the studies cited) · vs Placebo	Creatine reliably raises muscle creatine and is linked to better high-intensity exercise and training gains. Short- and long-term use (up to 30 g a day for 5 years in studies cited) was reported safe and well tolerated in healthy people. Qualitative (Not applicable) Methods, limits and funding Outcomes: Muscle creatine, high-intensity performance, training adaptations, safety Limitations: Expert consensus statement. The abstract does not describe individual side effects. Funding and conflicts: Not stated in the record read. Read: abstract
Kruszewski 2022 Effects of Multi-Ingredient Pre-Workout Supplement and Caffeine on Bench Press Performance: A Single-Blind Cross-Over Study. Nutrients · PMID 35565718 · DOI	Single blind crossover trial	15 15 resistance-trained men	A pre-workout blend (beta-alanine, citrulline malate, arginine alpha-ketoglutarate, taurine, tyrosine, caffeine) versus caffeine alone Oral One serving each (studied in the trial) Two sessions · vs Caffeine alone	Bench press repetitions were higher after caffeine alone than after the blend; mood scales were not different. The authors concluded the blend was less effective and less cost-effective than caffeine. Caffeine alone > blend for repetitions (Not given in the abstract) Methods, limits and funding Outcomes: Bench press repetitions, mood and arousal scales, perceived effort Limitations: 15 men, single-blind, one test. Funding and conflicts: No conflict declared. Read: abstract
Mancin 2026 Reducing the Risk of Unintentional Doping From Supplements: A Practical Guide for Athletes and Support Teams. Transl Sports Med · PMID 42639281 · DOI	Narrative review	Literature on supplements and anti-doping risk, 2000 to 2025	Sports supplements in general Oral	Contamination risk is described as highest for multi-ingredient products, pre-workout supplements, weight-loss, muscle-building and testosterone-booster products. The authors advise third-party certification and product checking. Qualitative (Not applicable) Methods, limits and funding Outcomes: Contamination, mislabelling, anti-doping violations Limitations: Narrative review, not a systematic or meta-analysis; it did not give numbers in the abstract. Funding and conflicts: No conflicts declared. Read: abstract
Ridha 2023 Pre-Workout-Induced Pancreatitis. Cureus · PMID 37795059 · DOI	Case report	1 One 35-year-old man with acute pancreatitis	A pre-workout supplement Oral	Other causes were ruled out, so the pre-workout was suspected. The authors note very little literature on the amino acid combinations in these products. One case (Not applicable) Methods, limits and funding Outcomes: Pancreatitis after exclusion of other causes Limitations: Single case; suspicion, not proof. Funding and conflicts: No competing interests. Read: abstract
Rodriguez Guerra 2023 Pre-workout Induced Demand Ischemia. Cureus · PMID 36793833 · DOI	Case report	1 One 35-year-old person, started a pre-workout recently	A pre-workout supplement Oral Recently started	Fast heart rate, raised troponin (a heart-strain blood marker) and mild overactive thyroid tests. The heart scan was normal, and symptoms and troponin improved within 36 hours with fluids. The authors urge doctors to consider hidden substances in supplements. One case (Not applicable) Methods, limits and funding Outcomes: Heart rate, troponin, thyroid tests Limitations: Single case. The abstract does not name the product or show a test of its contents. Funding and conflicts: No competing interests. Read: abstract
Shoshan 2021 Prevalence of Protein and Pre-Workout Supplement Use among High School Football Players and Potential Product Contamination. Glob Pediatr Health · PMID 34291127 · DOI	Cross sectional survey	102 102 US high-school football players, online questionnaire	Protein and pre-workout supplement use Oral	29.4% used pre-workout supplements and 59.8% used protein products. Five players used a pre-workout containing a substance banned by the NCAA. The authors say many products held banned, regulated-elsewhere or unknown substances. 29.4% used pre-workouts; 5 of 102 players used a product with a banned substance (Not applicable) Methods, limits and funding Outcomes: How many use these products and whether the products held banned substances Limitations: Small online sample; self-reported products; an NCAA ban is a sport rule, not a health finding. Funding and conflicts: No conflicts declared. Read: abstract
Solon-Júnior 2023 The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualification. J Sports Sci · PMID 38290812 · DOI	Systematic review meta analysis	8 studies (10 interventions) in physically active people	Tyrosine Oral Varied Acute · vs Placebo	No difference from placebo in time to exhaustion (SMD 0.02) or time trial (SMD -0.04). GRADE: moderate. The authors judged tyrosine ineffective for endurance performance. SMD 0.02 and -0.04 (Not given in the abstract) Methods, limits and funding Outcomes: Time to exhaustion and time-trial performance Limitations: Endurance only. Strength, power and thinking tasks were not the focus. Funding and conflicts: Not stated in the record read. Read: abstract
Trexler 2015 International society of sports nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr · PMID 26175657 · DOI	Position stand	Evidence on beta-alanine in healthy adults	Beta-alanine Oral Varied; see the position stand Weeks of daily intake · vs Placebo	Four weeks of daily beta-alanine raises muscle carnosine, which buffers acid in muscle. It appears safe in healthy people at studied amounts. The only reported side effect is tingling (paraesthesia), which smaller divided amounts or sustained-release forms reduce. It improves performance in efforts lasting 1 to 4 minutes after at least 2 to 4 weeks of daily intake. More research is needed on strength and on efforts longer than 25 minutes. Qualitative (Not applicable) Methods, limits and funding Outcomes: Muscle carnosine, exercise performance, side effects Limitations: Expert consensus statement; the benefit needs weeks of daily intake, not one pre-workout serving. Funding and conflicts: Not stated in the record read. Read: abstract
Wang 2020 PRE-WORKOUT SUPPLEMENT INDUCED CARDIAC ISCHAEMIA IN A YOUNG FEMALE. J Sports Sci · PMID 31783721 · DOI	Case report	1 One 33-year-old woman with chest tightness after strenuous exercise	A named pre-workout product (not repeated here) Oral	Chest tightness, near-fainting and breathlessness with a small troponin rise (50 ng/L) and no cardiac risk factors. She recovered after a 3-day admission. The author notes undisclosed proprietary blends make safety oversight hard. One case (Not applicable) Methods, limits and funding Outcomes: Troponin, symptoms Limitations: Single case; contents of the product were not tested in the abstract. Funding and conflicts: Not stated. Read: abstract
Wang 2026 Effects of Citrulline Malate Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-Analysis. Nutrients · PMID 42356270 · DOI	Systematic review meta analysis	644 30 randomised trials of citrulline malate, 644 people	Citrulline malate Oral Varied by trial Acute and chronic protocols · vs Placebo or control	Small overall improvement in performance (g = 0.16, p = 0.01) with wide prediction intervals; no significant effect on perceived exertion. Subgroup findings were not robust. GRADE certainty low to very low. g = 0.16 (Prediction intervals wide) Methods, limits and funding Outcomes: Exercise performance and perceived exertion Limitations: Heterogeneous trials; limited power; the authors call for trials with verified supplement composition. Funding and conflicts: No conflicts declared. Read: abstract
de Jonge 2023 Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine. Cardiovasc Toxicol · PMID 36639595 · DOI	Case report review	35 30 published case reports, 35 people with problems after synephrine-containing supplements (to August 2021)	Pre-workout and other supplements containing synephrine Oral Not compared	Most often chest pain, palpitations, fainting and dizziness. Diagnoses raised: ischaemic heart disease, abnormal heart rhythm, stroke-type problems. Five people were left disabled or stayed on medicine. The authors found an association, mainly with the heart and blood vessels, but cannot exclude caffeine or other ingredients as the cause. Case counts only (Not applicable) Methods, limits and funding Outcomes: Symptoms and diagnoses after use Limitations: Case reports cannot show how often problems happen or prove cause. Caffeine in the same products is a confounder. Funding and conflicts: No conflict declared. Read: abstract
s-fda-caffeine FDA consumer update: Spilling the Beans: How Much Caffeine is Too Much? (page read in full on 2026-10-26; content current 08/28/2024) · Source	Regulator page n/a			Methods, limits and funding Read: full page text
s-nccih-supplements NCCIH: Using Dietary Supplements Wisely (page read 2026-10-26) · Source	Regulator page n/a			Methods, limits and funding Read: full page text

What we do not know yet

No trial of a typical 18-ingredient blend was read.
No lab survey of metals or label accuracy in pre-workouts was read.
Regulator pages on DMAA, NIH ODS and USADA could not be read.
No interaction studies with named medicines were found.
Long-term safety beyond about eight weeks was not found.

How new research is added

New studies are found by a saved PubMed search and placed in a review queue before the page changes.

Lab markers

What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".

Other 4

●

Repetitions and power in a resistance workout

Higher with most blends tested; lower than caffeine alone in one trial in trials

How many repetitions a person completes with a set weight, and how much power the muscles produce, measured in the gym or lab.

Low certainty

Results and what it means

Why it was measured

To see whether a pre-workout lets people do more work in one session.

Statistical vs. clinical meaning

A one-session performance measure, not a long-term training result.

Safety implication

Short trials; no safety result reported in the abstracts.

Study	Result	People	Product
¹⁰	Repetitions 26.3 vs 23.5 (p = 0.022); higher peak and mean power	8 resistance-trained men	A pre-workout energy supplement 10 minutes before exercise
³	Repetitions 96.9 vs 89.5 (p = 0.003); lower effort rating	20 resistance-trained adults	One commercial pre-workout
¹⁸	More repetitions after caffeine alone than after the blend	15 resistance-trained men	Blend vs caffeine alone

^{10 3 18}

●

Cycling sprint power (Wingate test)

Higher in two small trials in trials

A 20 to 30 second all-out cycling sprint that measures peak and average power.

Low certainty

Results and what it means

Why it was measured

To measure short, hard effort of the kind pre-workouts claim to help.

Statistical vs. clinical meaning

Small gains in a lab test in small trials.

Safety implication

No safety outcome in the abstracts.

Study	Result	People	Product
⁸	Peak power p = 0.009 and mean power p = 0.04 better; total work not different	12 untrained young men	Pre-workout with beta-alanine, taurine, caffeine, tyrosine and cayenne
¹⁶	Mean power 8.7 vs 8.5 W/kg (p = 0.038)	23 resistance-trained men	A commercial pre-workout

^{8 16}

●

Pooled exercise performance scores (single ingredients)

Slightly higher, with wide uncertainty in trials

A combined score across many different exercise tests, used in pooled analyses to compare supplement and placebo.

Low certainty

Results and what it means

Why it was measured

To see whether one ingredient changes how people perform on average.

Statistical vs. clinical meaning

Small average effects with very different results between trials.

Safety implication

None reported in the abstracts.

Study	Result	People	Product
²⁶	g = 0.16 for citrulline malate	30 trials, 644 people	Citrulline malate
⁵	g = 0.25 (0.10 to 0.39) for a single taurine dose	23 trials, 308 people	Taurine

^{26 5}

●

Time to exhaustion and time trial

No change in trials

How long a person can keep going at a set effort, or how fast they finish a set distance.

Moderate certainty

Results and what it means

Why it was measured

To test endurance claims for citrulline and tyrosine.

Statistical vs. clinical meaning

For these two ingredients, endurance did not change on average.

Safety implication

None reported.

Study	Result	People	Product
¹²	Time to exhaustion SMD 0.03; time to completion SMD -0.07 (no difference)	9 studies, 158 people	Citrulline
²³	Time to exhaustion SMD 0.02; time trial SMD -0.04 (no difference)	8 studies, active adults	Tyrosine

^{12 23}

Safety

What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.

Main points to know 5

Most pre-workouts are mostly a caffeine product, and caffeine side effects are the usual problem. The FDA lists the signs of too much caffeine: faster heart rate, palpitations, high blood pressure, trouble sleeping, anxiety, jitters, upset stomach, nausea and headache. A 2019 survey found caffeine in 86% of top-selling pre-workouts, averaging 254 mg where amounts were listed. The FDA has cited 400 mg a day from all sources as an amount not generally associated with negative effects for most adults, and says sensitivity varies a lot. Caffeine can also be in bars, gum, other supplements and medicines, so add up all sources. Regulator statement and product survey ^{28 14}
Evening use can cost sleep. A pooled analysis of 24 studies found caffeine cut total sleep time by about 45 minutes, lowered sleep efficiency by 7% and reduced deep sleep. The authors estimated a standard pre-workout serve (217.5 mg caffeine) would need to be taken about 13 hours before bedtime to avoid shorter sleep. That is a model, and people differ. Meta-analysis ⁹
Stimulants such as synephrine can strain the heart. A review of 30 case reports (35 people) found chest pain, palpitations, fainting and dizziness after products containing synephrine, with diagnoses such as ischaemic heart disease and abnormal heart rhythm. Five people were left disabled or on medicine. The authors cannot exclude caffeine as a cause. Two further single case reports describe chest pain with a raised heart-strain marker (troponin) after starting a pre-workout. Case reports cannot show how common this is. Case reports ^{27 21 25}
The label may not tell you everything in the tub. NCCIH says products sold as supplements for weight loss, sexual enhancement and bodybuilding may contain prescription drugs not allowed in supplements, or ingredients not on the label. A 2026 review says contamination risk is highest for multi-ingredient products, pre-workouts, weight-loss, muscle-building and testosterone-booster products. In a survey of 102 high-school football players, five used a pre-workout containing a substance banned by the NCAA. In a 2019 survey, 44.3% of all listed ingredients were inside blends with amounts not disclosed. Regulator statement, narrative review and surveys ^{29 19 22 14}
Teens, children, pregnancy and heart conditions: ask a doctor first. The 2023 ISSN statement on energy drinks and shots says adolescents should use caution, products are not recommended for children aged 2 to 12, pregnancy, breastfeeding or caffeine sensitivity, and people with heart, metabolic, kidney, liver or nerve disease taking medicines that caffeine or stimulants could affect should consult a doctor. The FDA says medical experts advise against energy drinks for children and teens (American Academy of Pediatrics). NCCIH notes many supplements have not been tested in pregnant or nursing women or children. Expert statements ^{15 28 29}

Side effects 7

Effect	How often	Severity and recovery	Evidence
Fast heartbeat, palpitations, high blood pressure, jitters, anxiety, upset stomach, headache (from too much caffeine) Listed by the FDA as signs of too much caffeine; not measured in pre-workout trials read.	Not given; sensitivity varies	Mild to moderate Usually pass as caffeine wears off	Regulator statement ²⁸
Poorer sleep (shorter, lighter) Depends on timing and personal sensitivity.	Average effects in pooled studies: -45 minutes total sleep, -7% efficiency	Mild to moderate Reversible	Meta-analysis ⁹
Tingling of the skin (paraesthesia) from beta-alanine The ISSN statement calls it the only reported side effect of beta-alanine.	Common; not counted in the abstract	Mild Fades; smaller divided amounts or sustained-release forms reduce it	Position stand ²⁴
Chest pain, palpitations, fainting, abnormal heart rhythm after synephrine-containing products Association only; caffeine may have contributed.	35 people in 30 case reports	Can be serious Five people had lasting disability or stayed on medicine	Case report review ²⁷
Raised troponin (heart-strain marker) after starting a pre-workout Single cases; contents of the products were not shown.	Two single cases	Moderate Improved within days in both cases	Case reports ^{21 25}
Acute pancreatitis Other causes were excluded, but cause is not proven.	One case	Serious Not stated in the abstract	Case report ²⁰
Severe muscle breakdown (rhabdomyolysis) with kidney and liver injury The person used several performance products and exercised hard.	One case	Life-threatening Not stated in the abstract	Case report ¹

Liver

No controlled trial in the sources read reported liver injury from a standard pre-workout. A single case report describes liver and kidney injury with severe muscle breakdown in someone using several performance products. In a lab study one pre-workout was toxic to liver cells and a computer model flagged three of its compounds; this cannot show harm in people. ^{1 4}

How often. No frequency was found.

Monitoring. No agency monitoring advice for pre-workouts was read.

This is a safety connection. It is not evidence that Pre-Workout Supplements: What They Contain, Ingredient by Ingredient supports liver health.

Medicines and supplements 5

With	Why it matters	Importance	Evidence	What to do
Other caffeine sources (coffee, energy drinks, caffeine pills, other supplements, some medicines) supplement	Caffeine from all sources adds up.	The FDA says caffeine can be in bars, gum, supplements and over-the-counter medicines, and that the body treats added caffeine like natural caffeine.	Regulator statement Moderate certainty ²⁸	Check every label and add them up. Ask a pharmacist.
Medicines and medical conditions that increase caffeine sensitivity prescription		The FDA says certain conditions and some medications make people more sensitive to caffeine and advises talking to a health care provider.	Regulator statement Low certainty ²⁸	Ask a doctor or pharmacist before use if you take regular medicines.
Heart, blood pressure or stimulant-affected medicines prescription	Stimulants raise heart rate and blood pressure.	The ISSN energy-drink statement says people with heart disease taking medicines that caffeine or other stimulants may affect should consult a physician.	Position stand Low certainty ¹⁵	Ask a doctor first.
Specific prescription drugs (for example, individual blood pressure, antidepressant or ADHD medicines) prescription	No mechanism found for the blend.	No interaction study of a pre-workout blend with any named medicine was found in the sources read.	Absence of evidence Not enough evidence	Absence of a study is not proof of safety. Tell a doctor or pharmacist about all supplements.
Other sports supplements (creatine, protein, fat burners, other pre-workouts) supplement	Overlapping ingredients stack up.	The sources read did not test combinations of products. The 2018 review warns that many formulas hold the same ingredients.	Absence of evidence Not enough evidence ¹³	Compare labels so the same stimulant is not in two products.

Who should check first 6

Situation	Advice	Evidence
Pregnancy and breastfeeding	The ISSN statement does not recommend energy drinks and shots in pregnancy or breastfeeding. Ask a doctor or midwife before using a pre-workout.	Position statement ¹⁵
Children and teenagers	Not recommended for children aged 2 to 12 by the ISSN statement; teens should use caution; the FDA cites pediatric advice against energy drinks for children and teens.	Position statement and regulator statement ^{15 28}
Heart disease, high blood pressure or abnormal heart rhythm	Ask a doctor before use. Case reports link stimulant pre-workouts to heart symptoms.	Expert statement and case reports ^{15 27}
Caffeine sensitivity, anxiety or sleep problems	The sources describe caffeine as a cause of jitters, anxiety and poorer sleep. Ask a doctor if these are problems for you.	Regulator statement and meta analysis ^{28 9}
Tested athletes	Contamination risk is described as highest for pre-workouts. The 2026 review advises third-party certification and checking products.	Narrative review ¹⁹
Kidney or liver disease	The ISSN statement asks people with kidney or liver disease on affected medicines to consult a doctor. Ask a clinician before using any blend.	Position statement ¹⁵

Overdose, product quality and regulators

Summary. Pre-workouts as a type have no single toxicity profile because ingredients differ. The FDA estimates toxic effects such as seizures can occur with rapid intake of about 1,200 mg of caffeine, and warns that pure and highly concentrated caffeine products can cause death.

Animal. Not reviewed.

High dose or long term signals. Most safety studies lasted under eight weeks. Long-term safety of blends was not found.

Overdose response. Seek urgent care for seizures, chest pain or severe symptoms.

Genotoxicity. One lab study of one pre-workout showed mutagenic and genotoxic responses in cells; this was not tested in people.

Quality varies by product. The sources describe hidden ingredients and contamination as a real risk for this category, but no heavy-metal survey of pre-workouts was read.

Prescription drugs or unlisted ingredients in bodybuilding products. NCCIH says some products marketed for weight loss, sexual enhancement and bodybuilding may contain prescription drugs not allowed in supplements or ingredients not on the label. ²⁹

Contamination by product type. A 2026 review describes contamination risk as highest for multi-ingredient products, pre-workouts, weight-loss, muscle-building and testosterone-booster products. ¹⁹

Banned substances in products teens use. Of 102 high-school football players, 29.4% used pre-workouts and five used one containing an NCAA-banned substance. ²²

Hidden amounts. 44.3% of all ingredients in the 100 top sellers were in proprietary blends with undisclosed amounts, so a reader cannot compare them with a study or a limit. ¹⁴

Body	Action	Date
US Food and Drug Administration (United States)	Consumer update: the FDA has cited 400 mg of caffeine a day as an amount not generally associated with negative effects for most adults; lists signs of too much caffeine; says energy or protein bars, gum, dietary supplements and medicines may contain caffeine; and estimates toxic effects such as seizures with rapid intake of about 1,200 mg. source	2024-08-28
NCCIH (US National Center for Complementary and Integrative Health) (United States)	Says the FDA cannot review dietary supplements for safety and effectiveness before sale, and that products marketed for weight loss, sexual enhancement and bodybuilding may contain unlisted or prescription ingredients. source

When to get medical help

Chest pain, a racing or irregular heartbeat, fainting or trouble breathing after a pre-workout: call emergency services.
A seizure, severe confusion or repeated vomiting after a stimulant product: get emergency help.
Dark urine, severe muscle pain or weakness, or very little urine after hard exercise and a supplement: see a doctor urgently.
Severe belly pain that spreads to the back, with vomiting: see a doctor.
Swelling of the face or tongue, hives or wheezing: call emergency services.

Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.

General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.

Frequently asked questions

What is in a typical pre-workout?

A 2019 survey of 100 top sellers found about 18 ingredients on average. The most common were beta-alanine, caffeine, citrulline, tyrosine, taurine and creatine.

¹⁴

Does a pre-workout contain caffeine?

Most do. Caffeine was listed in 86% of the top sellers in the survey. The FDA notes other ingredients and products can also supply caffeine, so add up all sources.

^{14 28}

Is a blend proven because each ingredient was studied?

No. Most evidence is for one ingredient at a time. Trials of whole blends are small and short, and one trial found caffeine alone did better than a blend.

^{18 13}

Which ingredient has the best evidence?

Experts rate caffeine, beta-alanine and creatine most strongly on their own. Tyrosine did not help endurance, and citrulline and taurine show small, uncertain effects.

^{11 24 17 23 26 5}

What does a proprietary blend mean?

The label lists ingredients together with one total weight, so you cannot see each amount. In the 2019 survey, 44.3% of all ingredients were in such blends.

¹⁴

Can a pre-workout affect sleep?

Yes. Pooled studies found caffeine cut total sleep by about 45 minutes and lowered sleep efficiency. Timing and personal sensitivity matter.

⁹

Can it harm the heart?

Case reports link stimulant pre-workouts, especially with synephrine, to chest pain, palpitations and abnormal rhythm, and the review cannot rule out caffeine. Reports show something can happen, not how often.

^{27 2}

Are pre-workouts safe for teenagers?

The ISSN says adolescents should use caution, and the FDA cites pediatric advice against energy drinks for children and teens. Ask a doctor.

^{15 28}

Are pre-workouts safe in pregnancy?

The ISSN does not recommend energy drinks and shots in pregnancy or breastfeeding, and no pre-workout trials in pregnancy were found. Ask a doctor or midwife.

¹⁵

Can a product contain ingredients that are not on the label?

Yes. NCCIH says some bodybuilding products contain unlisted or prescription ingredients, and a 2026 review calls contamination risk highest for pre-workouts. Independent testing can help.

^{29 19}

Do the extra ingredients add anything beyond caffeine?

One small trial found no extra benefit; for taurine, a network analysis suggests caffeine plus taurine may help anaerobic effort and reaction time. Evidence is limited.

^{18 6}

Is a pre-workout better than coffee?

No trial comparing a blend with coffee was read. One small trial found caffeine alone did better than a blend.

¹⁸

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Editorial transparency

Written by: AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
Medical review: None. This page has not been reviewed by a physician or pharmacist.
First published: 2026-10-26
Last substantive update: 2026-10-26
How we research: We read the PubMed abstract of every study cited (not full texts) and the full text of the FDA caffeine consumer update and NCCIH supplement page. NIH ODS and USADA pages could not be read and are marked unverified.
How we rate evidence: See "How we rate evidence" in the Evidence tab.
Independence: No product is promoted on this page. No affiliate links are shown. One trial cited was paid for by the maker of the product it tested; this is flagged where it appears.

Sources 29

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

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Bella YF, Cupido SRS, Inacio PAQ et al. Pre-Workout Supplements and Their Effects on Cardiovascular Health: An Integrative Review.. J Cardiovasc Dev Dis. 2025. PMID 40278171. DOI 10.3390/jcdd12040112. (abstract)
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Carrão Dantas EK, Araújo-Lima CF, Ferreira CLS et al. Toxicogenetic assessment of a pre-workout supplement: In vitro mutagenicity, cytotoxicity, genotoxicity and glutathione determination in liver cell lines and in silico ADMET approaches.. Mutat Res Genet Toxicol Environ Mutagen. 2022. PMID 35914863. DOI 10.1016/j.mrgentox.2022.503517. (abstract)
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Rodriguez Guerra MA, Urena Neme AP, Shaban M et al. Pre-workout Induced Demand Ischemia.. Cureus. 2023. PMID 36793833. DOI 10.7759/cureus.33694. (abstract)
Shoshan T, Post E. Prevalence of Protein and Pre-Workout Supplement Use among High School Football Players and Potential Product Contamination.. Glob Pediatr Health. 2021. PMID 34291127. DOI 10.1177/2333794X211031202. (abstract)
Solon-Júnior LJF, Boullosa Alvarez DA, Martinez Gonzalez B et al. The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualification.. J Sports Sci. 2023. PMID 38290812. DOI 10.1080/02640414.2024.2309434. (abstract)
Trexler ET, Smith-Ryan AE, Stout JR et al. International society of sports nutrition position stand: Beta-Alanine.. J Int Soc Sports Nutr. 2015. PMID 26175657. DOI 10.1186/s12970-015-0090-y. (abstract)
Wang SSY. PRE-WORKOUT SUPPLEMENT INDUCED CARDIAC ISCHAEMIA IN A YOUNG FEMALE.. J Sports Sci. 2020. PMID 31783721. DOI 10.1080/02640414.2019.1689598. (abstract)
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de Jonge MLL, Kieviet LC, Sierts M et al. Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine.. Cardiovasc Toxicol. 2023. PMID 36639595. DOI 10.1007/s12012-022-09777-z. (abstract)
. FDA consumer update: Spilling the Beans: How Much Caffeine is Too Much? (page read in full on 2026-10-26; content current 08/28/2024). . . (full page text)
. NCCIH: Using Dietary Supplements Wisely (page read 2026-10-26). . . (full page text)

Where to buy

Check the label first. Whatever you buy, look for these:

The amount of the active ingredient per serving, not just the front-label claim
A third-party testing mark (USP, NSF or ConsumerLab)
Other ingredients and allergens
Ask a pharmacist about interactions with your medicines

Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.

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Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.