Vitamins & Supplements · Creatine form
Creatine Ethyl Ester (CEE)
Creatine ethyl ester (CEE) · also called CEE, creatine ethyl ester HCl, etil ester de creatina
Creatine ethyl ester (CEE) is a lab-made form of creatine sold with the claim that it is absorbed better than creatine monohydrate. In the one trial that compared them, it was not: blood creatine was lower and muscle creatine was no higher. Small trials of strength and sprints are mixed. CEE can raise blood creatinine and make kidney tests look worse than they are, so tell your doctor if you take it.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Creatine Ethyl Ester (CEE)
CEE is creatine changed by a chemical reaction so that it carries an ethyl group. It is sold as better absorbed than monohydrate, but the one head-to-head trial did not show that, and CEE can raise blood creatinine.
What creatine ethyl ester is
Creatine is a compound found in muscle and made in the body; meat and fish also supply it. Creatine ethyl ester is a lab-made form. A 2022 critical review describes it as a chemical alteration of creatine, made by adding an ethyl group, and says it is not actually creatine. It would have to lose that group cleanly to act like creatine.
Sellers say it dissolves better, is absorbed faster and more completely, needs no loading phase and causes less bloating. The same review says these claims are not backed by evidence. See the main creatine page for creatine monohydrate.
What happens to it in the lab
Lab studies disagree. One found that in mild watery conditions CEE turned into creatinine, an inactive waste product, and not into creatine. Another calculated that CEE breaks down in blood in about a minute. A third found CEE was most stable in very strong acid, where it gives creatine, and passed across cell layers better than creatine.
These are test-tube and cell results, not measurements in people, so they cannot settle whether CEE works in the body.
What the research in people shows
The one trial that compared CEE with monohydrate and placebo (30 untrained men, 7 weeks) found CEE did not raise blood creatine, raised muscle creatine about as much as monohydrate, and gave no extra strength or body composition gain. A 4-week soccer trial with 10 players per group favoured CEE and creatine hydrochloride on some tests.
A 2022 systematic review of 17 trials of alternative forms found no consistent gain over placebo and only 3 trials that compared with monohydrate. The trials are small and short, and some reviewers have ties to the creatine industry.
Kidney blood tests
Creatinine is the waste product doctors use to judge kidney filtering. CEE raised it in the trial, and two case reports describe raised creatinine on CEE that returned to normal after stopping, one in a kidney transplant recipient whose graft checks were normal. This can look like kidney trouble that is not there.
No long-term safety study was found. Ask a doctor or pharmacist before using it, especially with kidney disease, and tell whoever orders your tests. For creatine in general, see the kidney page linked below.
Labels and quality
A survey of 175 creatine products on one online shop found 16 non-monohydrate forms, about 22 percent blends of forms and only 8 percent third-party certified. The survey did not say which products held CEE. Check the label for the form.
Food versus pills
CEE is not a food. Creatine itself comes from meat and fish. See the creatine-in-food page for foods and amounts.
At a glance
Traditional uses history, not proof
- No food or traditional use; a lab-made form of creatine
- Sold as powders and capsules for training, alone or in blends
Studied for research
- Better absorption than monohydrate, evidence against
- Muscle creatine, low certainty
- Strength, jumps and sprints, mixed certainty
- Thinking tasks, insufficient evidence
- Blood creatinine rise, low certainty (a safety signal)
Main compounds
- Creatine ethyl ester
- Creatine ethyl ester hydrochloride
- Creatinine (breakdown product)
Common forms
- Powders and capsules
- Blends with other creatine forms
Research links: 2009 trial: CEE vs monohydrate vs placebo, 30 men · 2022 critical review of creatine forms · 2022 systematic review of alternative creatine forms (17 trials) · 2019 case report: raised creatinine after CEE in a transplant recipient · 2013 lab study: stability of CEE at different acidity · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Creatine ethyl ester (CEE), also sold as creatine ethyl ester hydrochloride
- Synonyms
- Creatine ethyl ester HCl
- Common names
- Creatine ethyl ester (English); CEE (English); Etil ester de creatina (Spanish)
- Family or group
- A chemically altered form of creatine (an ester). Kreider 2022 describes it as creatine with a hydrogen removed and an ethyl group added through a reaction.
- Harvest and processing
- Made by a chemical reaction (esterification) of creatine, per Kreider 2022.
- Look-alikes and adulterants
- Name: Creatine monohydrate; Note: The most studied form; a different product with its own page.; Name: Creatine hydrochloride; Note: A different form that is sometimes combined with CEE; it has its own page.; Name: Creatinine; Note: A waste product, not a supplement; CEE can turn into it.
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
Traditional use shows how it was used. It does not show that it works or is safe today.
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 |
|---|---|---|---|---|
| Creatine ethyl ester | creatine ester | About 6.3 percent less creatine by molecular weight than monohydrate, per Kreider 2022. | Marketed as better absorbed; trial and lab evidence do not show this. 9 12 | Human data |
| Creatinine | breakdown product | Not read from a source. | An inactive waste product that CEE can turn into in solution. 4 5 | Lab |
| Ethanol | alcohol | Not read from a source. | Released with creatine when CEE splits in very strong acid (lab study). 5 | Lab |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Turning into creatinine instead of creatine | Not applicable | In water and buffer, CEE turned into creatinine, nearly instantly near pH 7.4 (Giese 2009). In very strong acid it was stable and gave creatine (Gufford 2013). Lab only. 4 5 | Lab |
| Fast breakdown in blood | Not applicable | A calculation gave a blood half-life of about one minute (Katseres 2009), suggesting it may not reach muscle as the ester. Lab and calculation only. 7 | Lab |
Absorption, metabolism and elimination
- Absorption
- Lab work suggests CEE crosses cell layers better than creatine (Gufford 2013), but in the trial CEE did not raise blood creatine compared with monohydrate (Spillane 2009).
- Distribution
- Not studied in people for CEE beyond muscle creatine in one trial.
- Metabolism
- Lab studies show conversion to creatinine; reviews disagree on how much occurs in the stomach.
- Elimination
- Not found.
- Bioavailability
- Not shown to exceed monohydrate; the 2022 review calls it less efficient than assumed.
Isolated compounds versus whole extracts
CEE is a made form, not a food. Creatine itself comes from meat and fish and the body makes some; CEE is not found in food. Food creatine and pills differ in amount and form.
Nutritional composition
This page does not state food amounts; see the creatine page for creatine in food.
1 mixed findings1 low certainty1 not enough evidence1 evidence against
What was looked at
The 4 benefits and uses checked for Creatine Ethyl Ester (CEE), each with how strong the evidence is. Tap one to open it.
- The 'better absorbed than monohydrate' claimEvidence against
- Muscle creatineLow certainty
- Strength, jumps and sprint performanceMixed findings
- Thinking and reaction tasksNot enough evidence
Lab markers tracked in the studies
Creatine in the blood (serum)Total creatine in muscleCreatinine in the blood (serum creatinine)Peak power in a cycling sprint test (Wingate)Reaction time
What is Creatine Ethyl Ester (CEE) good for?
The main studied questions and how strong the human evidence is for each. All results are for CEE as a supplement in small groups; none is a long-term study.
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.
The 'better absorbed than monohydrate' claim
Evidence againstSellers say CEE is absorbed faster and more fully than creatine monohydrate. In the one trial that measured it, CEE did not do better: blood creatine was lower than with monohydrate and muscle creatine was no higher.
4 studiesCEE and monohydrate, both as powders in the trial (study amounts are …
Studies, doses and limits
What the trials found
A 7-week trial in 30 untrained men found serum creatine was higher with placebo and with monohydrate than with CEE, and muscle creatine was higher than placebo with both creatine forms with no difference between them. A 2022 critical review says the claims for CEE are not backed by evidence and a 2011 review found little to no evidence that newer forms are better than monohydrate. A 2022 systematic review of 17 trials of alternative forms found only 3 compared with monohydrate.
Results
Not supported by the trial that tested it. The other trials cannot answer this question because they did not measure creatine levels against monohydrate.
Effect sizes as reported
Serum creatine: monohydrate higher than CEE (p = 0.005). Muscle creatine: no difference between CEE and monohydrate.
Why this rating
One small trial (30 men) and reviews whose authors have industry ties. The direction is consistent, but the trial is small and short.
Form and dose studied
CEE and monohydrate, both as powders in the trial (study amounts are in the studies table).
Who was studied
Untrained young men in the trial.
Limits
One trial, 7 weeks, 30 men in three groups. Lab studies point in different directions.
Why researchers looked
The claim is the main reason CEE is sold, so it is the first thing readers ask about.
Traditional use
Creatine itself is made in the body and found in meat and fish. Creatine ethyl ester is a lab-made form sold as a supplement; it has no food or traditional use of its own.
Proposed mechanism Proposed mechanism
CEE is creatine with an ethyl group added by a chemical reaction. For it to act like creatine, the ethyl group must come off cleanly. Lab studies disagree on how much does; some show it turns into creatinine instead. These are test-tube results, not measured in people.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for the creatinine rise.
Muscle creatine
Low certaintyIn the one trial that measured it, muscle creatine rose above placebo with CEE, about as much as with monohydrate. So CEE did raise muscle creatine in that trial, but not more than monohydrate.
2 studiesCEE in a loading then maintenance pattern, as studied.
Studies, doses and limits
What the trials found
In the 7-week trial, total muscle creatine was higher with monohydrate (p = 0.026) and with CEE (p = 0.041) than with placebo, with no difference between the two. A lab study that calculated CEE breaks down in blood in about a minute suggests it may not reach muscle as the ester, though some of it may still arrive as creatine.
Results
Preliminary. One small trial shows a rise in muscle creatine with CEE, equal to monohydrate.
Effect sizes as reported
Muscle creatine higher than placebo (p = 0.041 for CEE); CEE vs monohydrate no difference.
Why this rating
Low: a single 30-man trial, short, no repeat.
Form and dose studied
CEE in a loading then maintenance pattern, as studied.
Who was studied
Untrained young men.
Limits
No second trial measured muscle creatine for CEE alone.
Why researchers looked
Muscle creatine is what a creatine supplement is meant to raise.
Traditional use
Creatine itself is made in the body and found in meat and fish. Creatine ethyl ester is a lab-made form sold as a supplement; it has no food or traditional use of its own.
Proposed mechanism Established nutrition
Creatine is stored in muscle as phosphocreatine and used for quick energy; this is established for creatine in general. How well CEE does the same is not settled.
A proposed mechanism does not show that the effect happens in people.
Strength, jumps and sprint performance
Mixed findingsResults are mixed. The 7-week trial found no difference in strength or body composition between CEE, monohydrate and placebo. A small 4-week soccer trial found larger gains with CEE and creatine hydrochloride than monohydrate on some tests.
4 studiesCEE or creatine hydrochloride versus monohydrate; amounts differ betw…
Studies, doses and limits
What the trials found
The 7-week trial (30 untrained men) saw body composition, strength and power change over time with no differences between groups. The 2022 review also describes a 6-week study of underweight untrained men where CEE beat placebo for body weight and leg press strength, but with no monohydrate group and no muscle creatine measure. A 4-week trial of 40 soccer players (10 per group) found all creatine groups beat placebo, and the CEE and hydrochloride groups gained more than monohydrate on jumps, sprint, L-run and peak power. A 2022 systematic review of 17 trials found no consistent performance gain for alternative forms over placebo.
Results
Mixed. Small, short trials disagree, and none shows a clear lasting edge over monohydrate.
Effect sizes as reported
Soccer trial: CEE and hydrochloride vs monohydrate p < 0.05 on jumps, sprint, peak power. 7-week trial: no group differences.
Why this rating
Mixed: two small trials point opposite ways, and the review found no consistent gain.
Form and dose studied
CEE or creatine hydrochloride versus monohydrate; amounts differ between studies.
Who was studied
Untrained men, underweight men, and young male soccer players.
Limits
Group sizes of 10; short; men only; the soccer trial's abstract does not state the CEE amount.
Why researchers looked
Creatine forms are mainly sold for training performance.
Traditional use
Creatine itself is made in the body and found in meat and fish. Creatine ethyl ester is a lab-made form sold as a supplement; it has no food or traditional use of its own.
Proposed mechanism Proposed mechanism
The idea is that more muscle creatine allows more work in short efforts. Whether CEE does this better than monohydrate is not shown.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for the blood creatinine rise.
Thinking and reaction tasks
Not enough evidenceEvidence is thin. One 2009 study reported better scores on some thinking tasks with CEE and said it needs repeating. A 2026 menopause trial tested CEE only in a blend and did not report a benefit for the blend.
2 studiesCEE alone (2009) and CEE with creatine hydrochloride (2026).
Studies, doses and limits
What the trials found
Ling 2009 (double-blind, placebo-controlled; the abstract gives no numbers) reported improvement on several of five cognitive tasks and said the results need replication using objective measures of compliance. Korovljev 2026 randomised 36 perimenopausal and menopausal women to creatine hydrochloride alone, creatine hydrochloride plus CEE (800 mg a day) or placebo for 8 weeks; the medium-dose hydrochloride group beat placebo on reaction time and frontal brain creatine, and the abstract does not report a benefit for the blend. All interventions were reported as well tolerated.
Results
Insufficient evidence for CEE alone. The one positive study is small, old and unrepeated.
Effect sizes as reported
Not reported for CEE.
Why this rating
Insufficient: one small, old study without objective compliance checks, and a trial where CEE was only part of a blend.
Form and dose studied
CEE alone (2009) and CEE with creatine hydrochloride (2026).
Who was studied
Healthy volunteers; menopausal women.
Limits
Neither study isolates CEE with a clear result.
Why researchers looked
Creatine is also studied for brain energy.
Traditional use
Creatine itself is made in the body and found in meat and fish. Creatine ethyl ester is a lab-made form sold as a supplement; it has no food or traditional use of its own.
Proposed mechanism Proposed mechanism
The proposed idea is that brain energy capacity affects thinking performance. This is untested for CEE in the studies read.
A proposed mechanism does not show that the effect happens in people.
Connections to the rest of health
How Creatine Ethyl Ester (CEE) 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
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Peak Performance | Evidence against | The 'better absorbed than monohydrate' claim: Sellers say CEE is absorbed faster and more fully than creatine monohydrate. In the one trial that measured it, CEE did not do better: blood creatine was lower than with monohydrate and muscle creatine was no higher. Strength, jumps and sprint performance: Results are mixed. The 7-week trial found no difference in strength or body composition between CEE, monohydrate and placebo. A small 4-week soccer trial found larger gains with CEE and creatine hydrochloride than monohydrate on some tests. | 12 9 6 3 1 | |
| Peak Performance | Low certainty | Muscle creatine: In the one trial that measured it, muscle creatine rose above placebo with CEE, about as much as with monohydrate. So CEE did raise muscle creatine in that trial, but not more than monohydrate. | 12 7 | |
| Focus And Memory | Not enough evidence | Thinking and reaction tasks: Evidence is thin. One 2009 study reported better scores on some thinking tasks with CEE and said it needs repeating. A 2026 menopause trial tested CEE only in a blend and did not report a benefit for the blend. | 11 8 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Musculoskeletal System | Biological association | Evidence against | Studied for: The 'better absorbed than monohydrate' claim Studied for: Muscle creatine | 12 9 6 3 7 1 |
| Bones Joints Muscles | Biological association | Evidence against | Studied for: The 'better absorbed than monohydrate' claim Studied for: Strength, jumps and sprint performance | 12 9 6 3 1 |
| Nervous System | Biological association | Not enough evidence | Studied for: Thinking and reaction tasks | 11 8 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Kidney diseases | Case report | A kidney transplant recipient's creatinine rose on CEE and normalised after stopping. Preparation or compound: Creatine ethyl ester |
10 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Creatinine | Clinical trial and case reports | CEE raised blood creatinine in a 7-week trial and two case reports, which can make kidney tests look worse than they are. Preparation or compound: Creatine ethyl ester |
12 10 13 | |
| Creatine in the blood (serum) | Biological association | Low certainty | Measured in trials: higher with monohydrate, not with CEE. A lab change is not the same as a health benefit. | 12 |
| Total creatine in muscle | Biological association | Low certainty | Measured in trials: higher. A lab change is not the same as a health benefit. | 12 |
| Creatinine in the blood (serum creatinine) | Biological association | Low certainty | Measured in trials: higher. A lab change is not the same as a health benefit. | 12 10 13 9 |
| Peak power in a cycling sprint test (Wingate) | Biological association | Low certainty | Measured in trials: higher. A lab change is not the same as a health benefit. | 1 12 |
| Reaction time | Biological association | Not enough evidence | Measured in trials: faster. A lab change is not the same as a health benefit. | 8 |
K. Biological pathways
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Creatine ethyl ester | Biological association | Human | Marketed as better absorbed; trial and lab evidence do not show this. | 9 12 |
| Creatinine | Biological association | Lab | An inactive waste product that CEE can turn into in solution. | 4 5 |
| Ethanol | Biological association | Lab | Released with creatine when CEE splits in very strong acid (lab study). | 5 |
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 4 outcomes
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.
The evidence
The research centre for Creatine Ethyl Ester (CEE). 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 started from our existing CEE summary, re-read PubMed abstracts for every trial, case report and review listed, and read the 2022 Kreider review in full via Europe PMC.
Study library: every study we checked 13
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Duan 2026 Creatine formulations and repeated sprint training: effects on physical and physiological adaptations in soccer players during the short-term preparation phase. J Int Soc Sports Nutr · PMID 42720250 · DOI |
Randomised controlled trial |
40 40 male collegiate soccer players, 4 weeks of repeated sprint training (10 per group) |
Creatine monohydrate, creatine ethyl ester, creatine hydrochloride or placebo Oral supplement 4 weeks, 12 training sessions · vs Placebo and creatine monohydrate |
All groups improved with training. The creatine groups improved more than placebo on physical performance, peak power and fatigue index. The ethyl ester and hydrochloride groups showed larger gains than the monohydrate group on jumps, sprint, L-run and peak power. Mean power and VO2max did not differ between groups. Creatine groups vs placebo p = 0.001; ethyl ester and hydrochloride vs monohydrate p < 0.05 (Not reported in the abstract) Methods, limits and fundingOutcomes: Countermovement jump, 20 m sprint, L-run, Wingate peak power and fatigue index, VO2max Limitations: Only 10 people per group, 4 weeks, one sport; the training amount of each form is not stated in the abstract. This result runs against the earlier 7-week trial, so one trial does not settle the question. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Escalante 2022 Analysis of the efficacy, safety, and cost of alternative forms of creatine available for purchase on Amazon.com: are label claims supported by science? Heliyon · PMID 36544833 · DOI |
Market survey not applicable |
175 175 creatine products for sale on Amazon.com |
Creatine products Powders, capsules and other forms |
The products contained 16 forms of creatine other than monohydrate. About 21.7 percent were blends of different forms. Only 8 percent were third-party certified. About 88 percent of the alternative creatine products were classed as having limited to no evidence for bioavailability, efficacy and safety. Blends 21.7%; third-party certified 8%; limited or no evidence about 88% (Not applicable) Methods, limits and fundingOutcomes: Forms, label claims, third-party certification, cost Limitations: A snapshot of one online shop at one time; the abstract does not say which products contained CEE. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Fazio 2022 Efficacy of Alternative Forms of Creatine Supplementation on Improving Performance and Body Composition in Healthy Subjects: A Systematic Review. J Strength Cond Res · PMID 36000773 · DOI |
Systematic review |
17 randomised placebo-controlled trials of non-monohydrate creatine forms in healthy people | Alternative creatine forms: magnesium-creatine chelate, citrate, malate, ethyl ester, nitrate, pyruvate Oral supplement Varies between trials Varies · vs Placebo; only 3 trials also compared with monohydrate |
Only 3 of the 17 trials compared an alternative form with monohydrate. There were no consistent findings of performance gains for alternative forms compared with placebo. Monohydrate remained the most studied and the lowest-cost form. No pooled numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Exercise performance and body composition Limitations: Few trials per form; the abstract does not separate out CEE. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Giese 2009 Non-enzymatic cyclization of creatine ethyl ester to creatinine. Biochem Biophys Res Commun · PMID 19660433 · DOI |
Laboratory study lab |
Test-tube study (water and phosphate-buffered saline at 37 C) | Creatine ethyl ester Test-tube solution |
In mild watery conditions CEE turned into creatinine, an inactive waste product, as the only product, and this became nearly instant near pH 7.4. The authors conclude CEE is a pronutrient for creatinine rather than creatine and expect no performance effect. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Products formed from CEE in solution Limitations: Lab study only; not measured in people. The authors' conclusion is stronger than later work: another lab study found CEE fairly stable in very strong acid. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Gufford 2013 pH-dependent stability of creatine ethyl ester: relevance to oral absorption. J Diet Suppl · PMID 23957855 · DOI |
Laboratory study lab |
Test-tube and cell-layer study (Caco-2 cells, pig skin) | Creatine ethyl ester hydrochloride Test-tube solution and cell layers |
CEE was most stable in very strong acid (half-life 570 hours at pH 1.0), where it turns into creatine and ethanol. At pH 1.0 and above it turns into creatinine, faster as pH rises. It crossed cell layers better than creatine or creatinine. The authors suggest CEE may have better oral absorption potential than creatine, which has not been shown in people. Half-life 570 hours at pH 1.0; 23 seconds above pH 8.0 (Not applicable) Methods, limits and fundingOutcomes: Stability at different acidity; passage across cells Limitations: Lab and cell study only. Its more hopeful reading differs from the trial, where CEE did not raise serum creatine. Funding and conflicts: Listed as US National Institutes of Health extramural and non-US government support in the database record. Read: abstract |
| Jager 2011 Analysis of the efficacy, safety, and regulatory status of novel forms of creatine. Amino Acids · PMID 21424716 · DOI |
Narrative review mixed |
Review of newer creatine forms versus monohydrate | Creatine monohydrate and newer forms Oral supplement |
The authors report little to no evidence that any newer form of creatine is more effective or safer than monohydrate, and say the safety, efficacy and regulatory status of other forms is less clear. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Efficacy, safety and regulatory status of newer creatine forms Limitations: A narrative review from 2011; newer trials have appeared since. Abstract read only. Funding and conflicts: The authors have ties to the creatine industry (see the 2022 review for the same group). Read: abstract |
| Katseres 2009 Non-enzymatic hydrolysis of creatine ethyl ester. Biochem Biophys Res Commun · PMID 19524547 · DOI |
Laboratory study lab |
Test-tube study at 37 C across pH 1.6 to 7.0 | Creatine ethyl ester Test-tube solution |
The authors calculate that the half-life of CEE in blood is about one minute, suggesting it may break down too quickly to reach muscle cells as the ester. Blood half-life about 1 minute (calculated) (Not applicable) Methods, limits and fundingOutcomes: Rate at which CEE breaks down Limitations: Lab and calculation only; not measured in people. Funding and conflicts: Listed as non-US government research support in the database record; no company named. Read: abstract |
| Korovljev 2026 The Effects of 8-Week Creatine Hydrochloride and Creatine Ethyl Ester Supplementation on Cognition, Clinical Outcomes, and Brain Creatine Levels in Perimenopausal and Menopausal Women (CONCRET-MENOPA): A Randomized Controlled Trial. J Am Nutr Assoc · PMID 40854087 · DOI |
Randomised controlled trial |
36 36 apparently healthy perimenopausal and menopausal women, mean age 50.1, 8 weeks |
Creatine hydrochloride alone, or creatine hydrochloride plus creatine ethyl ester, or placebo Oral supplement Creatine hydrochloride 750 or 1,500 mg a day, or creatine hydrochloride plus creatine ethyl ester 800 mg a day (study amounts) 8 weeks · vs Placebo |
Medium-dose creatine hydrochloride beat placebo on reaction time, frontal brain creatine and blood lipids. The abstract highlights this group and does not report a benefit for the creatine hydrochloride plus CEE group. All interventions were well tolerated with no severe adverse effects reported. Medium-dose creatine hydrochloride vs placebo: reaction time p < 0.01 (this is the hydrochloride form, not CEE) (Not reported in the abstract) Methods, limits and fundingOutcomes: Cognition, mood, brain creatine, blood markers, adverse effects Limitations: Only 36 women across four groups. CEE was tested only as a blend with creatine hydrochloride, so the trial cannot say what CEE alone does. Registered as NCT06660004. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Kreider 2022 Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review. Nutrients · PMID 35268011 · DOI |
Narrative review mixed |
Review of marketed creatine forms, including CEE (full text read via Europe PMC) | Creatine monohydrate and other marketed creatine forms including CEE Oral supplement |
The authors conclude that monohydrate is the only creatine source with substantial evidence for bioavailability, efficacy and safety. In the full text they call CEE a chemical alteration of creatine, say lab and trial data suggest it is less efficient than assumed, note that CEE has about 6.3 percent less creatine than monohydrate by molecular weight, and report FDA new dietary ingredient notifications for CEE (2003) and CEE hydrochloride (2004), with several creatine-form notifications initially objected to by the FDA. No pooled numbers (Not applicable) Methods, limits and fundingOutcomes: Bioavailability, efficacy, safety and regulatory status of creatine forms Limitations: A narrative review, not a systematic one. The authors have ties to the creatine industry. FDA files were not opened by us. Funding and conflicts: The authors have worked with the creatine industry, mainly on monohydrate; this is a possible bias, and it is why the review is read alongside independent trials. Read: full-text (Europe PMC) |
| Law 2019 Elevation of serum creatinine in a renal transplant patient following oral creatine supplementation. Clin Kidney J · PMID 31384454 · DOI |
Case report |
1 One kidney transplant recipient |
Oral creatine ethyl ester (CEE), but not creatine monohydrate Oral supplement |
Serum creatinine was raised while taking CEE, but not while taking monohydrate. Standard checks for transplant problems, including ultrasound and biopsy, were normal, and creatinine returned to normal after the supplement was stopped. The authors say that in such cases creatinine is not a valid stand-in for true kidney filtering. Case report: no numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Serum creatinine; tests for graft problems Limitations: A single case report; it shows a possible link, not how common it is. Funding and conflicts: Not applicable (case report). Read: abstract |
| Ling 2009 Cognitive effects of creatine ethyl ester supplementation. Behav Pharmacol · PMID 19773644 · DOI |
Controlled clinical trial |
Healthy volunteers tested on five cognitive tasks (number not given in the abstract) | Creatine ethyl ester Oral supplement · vs Placebo |
Creatine dosing led to improvement over placebo on several measures. The authors say the results need replication using objective measures of compliance. No numbers in the abstract (Not reported) Methods, limits and fundingOutcomes: Performance on five cognitive tasks Limitations: Number of people, dose and length are not in the abstract; compliance was not checked objectively. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Spillane 2009 The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels. J Int Soc Sports Nutr · PMID 19228401 · DOI |
Randomised controlled trial |
30 30 non-resistance-trained men, 7 weeks with heavy resistance training |
Creatine ethyl ester (CEE), creatine monohydrate (CRT) or maltodextrose placebo Oral powder About 20 g a day for 5 days, then about 5 g a day for 42 days (study amounts, 0.30 then 0.075 g per kg fat-free mass) 7 weeks (5 + 42 days) · vs Maltodextrose placebo and creatine monohydrate |
Serum creatine was higher with placebo and monohydrate than with CEE. Serum creatinine was greater with CEE than with placebo or monohydrate and rose at days 6, 27 and 48. Total muscle creatine was higher than placebo with both monohydrate and CEE, with no difference between the two. Body composition, strength and power changed over time but not between groups. The authors concluded CEE was not as effective as monohydrate. Serum creatine: monohydrate vs CEE p = 0.005. Serum creatinine: CEE vs placebo p = 0.001 and vs monohydrate p = 0.001. Muscle creatine: monohydrate p = 0.026 and CEE p = 0.041 vs placebo. (Not reported in the abstract) Methods, limits and fundingOutcomes: Body composition, muscle strength and power, serum and muscle creatine, serum creatinine Limitations: Small trial (30 men split into three groups) in untrained men; 7 weeks. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Velema 2011 Elevated plasma creatinine due to creatine ethyl ester use. Neth J Med · PMID 21411845 |
Case report |
1 One person using creatine ethyl ester |
Creatine ethyl ester Oral supplement |
Plasma creatinine was raised while using CEE and had normalised one week after stopping. The authors say CEE may be converted into creatinine in the gut and that use may lead to a false assumption of kidney failure. Case report: no numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Plasma creatinine Limitations: A single case report; the stated gut conversion is the authors' explanation, not measured in the case. Funding and conflicts: Not applicable (case report). Read: abstract |
What we do not know yet
- No long-term safety study of CEE was found.
- Only one trial compared CEE with monohydrate for blood and muscle creatine.
- The soccer trial's abstract does not state the CEE amount.
- No data in pregnancy, breastfeeding or children were found.
- FDA database entries were not opened; they are described through one review.
- The NIH Office of Dietary Supplements was not checked for CEE.
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 5
Creatine in the blood (serum)
Higher with monohydrate, not with CEE in trials
The amount of creatine itself circulating in the blood after taking a supplement.
Low certaintyResults and what it means
Why it was measured
To see whether a form of creatine actually gets into the blood as creatine.
Statistical vs. clinical meaning
Suggests CEE is not a reliable source of blood creatine, though it is one small trial.
Safety implication
None on its own.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Higher with placebo and monohydrate than with CEE (p = 0.007 and p = 0.005) | 30 untrained men, 7 weeks | CEE vs monohydrate vs placebo |
Total creatine in muscle
Higher in trials
The creatine content of a small muscle sample.
Low certaintyResults and what it means
Why it was measured
The main way to see whether a supplement gets creatine into muscle.
Statistical vs. clinical meaning
CEE raised muscle creatine in this one trial, not above monohydrate.
Safety implication
None on its own.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Higher than placebo with CEE (p = 0.041) and monohydrate (p = 0.026); no difference between them | 30 untrained men, 7 weeks | CEE vs monohydrate vs placebo |
Creatinine in the blood (serum creatinine)
Higher in trials
A waste product made from creatine. Doctors use it to estimate how well the kidneys filter the blood.
Low certaintyResults and what it means
Why it was measured
Lab studies show CEE can turn into creatinine, so this number can read high even if the kidneys are fine.
Statistical vs. clinical meaning
A raised result can look like poor kidney function. It does not prove kidney damage, and no long-term study of CEE was found.
Safety implication
Tell whoever orders your blood tests. See the Safety tab.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Greater with CEE than with placebo or monohydrate (p = 0.001 each), at days 6, 27 and 48; the 2022 review describes more than a two-fold rise | 30 untrained men, 7 weeks | CEE vs monohydrate vs placebo |
| 10 | Raised on CEE, not on monohydrate; normalised after stopping | One kidney transplant recipient | Oral CEE |
Peak power in a cycling sprint test (Wingate)
Higher in trials
The highest power a person can produce in a short all-out cycling test.
Low certaintyResults and what it means
Why it was measured
A common test of short, hard efforts, the kind creatine is meant to help.
Statistical vs. clinical meaning
Small trial; not repeated; the 7-week trial found no group differences in strength or power.
Safety implication
None on its own.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | Ethyl ester and hydrochloride groups showed larger peak power gains than monohydrate (p < 0.05) | 40 young male soccer players, 4 weeks | CEE, creatine hydrochloride or monohydrate with sprint training |
Reaction time
Faster in trials
How fast a person responds to a signal on a computer test.
Not enough evidenceResults and what it means
Why it was measured
Used as a simple measure of thinking speed.
Statistical vs. clinical meaning
The finding was for creatine hydrochloride, not CEE alone.
Safety implication
No severe adverse effects reported in the trial.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | Medium-dose creatine hydrochloride beat placebo (1.2 vs 6.6 percent change, p < 0.01); no benefit reported for the creatine hydrochloride plus CEE group | 36 perimenopausal and menopausal women, 8 weeks | Creatine hydrochloride alone or with CEE |
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 3
- CEE can raise blood creatinine, which can look like poor kidney function. In a 7-week trial, serum creatinine was higher with CEE than with placebo or monohydrate. Two case reports describe raised creatinine on CEE that returned to normal after stopping, one in a kidney transplant recipient whose graft tests were normal. A raised result can send doctors looking for kidney trouble that is not there. Clinical trial and case reports 12 10 13 9
- Long-term safety is not known. No long-term safety study of CEE was found. Reviews ask for more safety research on forms of creatine other than monohydrate. Review 9 6
- Products often mix several creatine forms and are rarely independently tested. In a survey of 175 creatine products on one online shop, about 22 percent were blends of forms and only 8 percent were third-party certified. Market survey 2
Side effects 2
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Raised blood creatinine Not proof that CEE harms the kidneys. Ask a doctor if a test looks off. | Raised in the CEE group of a 30-man, 7-week trial; two case reports. The trial abstract notes values were above placebo and monohydrate at days 6, 27 and 48. | A lab-test change; kidney damage was not found in the case reports' checks Normalised after stopping in both case reports (within one week in one). | Clinical trial and case reports 12 10 13 |
| Other side effects Abstract-level only. Absence of reports is not proof of safety. | No severe adverse effects were reported in the 2026 menopause trial of creatine hydrochloride with or without CEE; the other trial abstracts do not list side effects. | Not reported Not reported | Clinical trial 8 |
Liver
No liver injury linked to CEE was found in the sources read.
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Creatine Ethyl Ester (CEE) supports liver health.
Medicines and supplements 2
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Kidney blood tests (serum creatinine, estimated kidney filtering) lab test | Lab studies show CEE can turn into creatinine, and case reports link CEE to raised creatinine; one report says CEE, unlike monohydrate, is converted into creatinine in the gut (the authors' explanation). | Creatinine can read high without a real drop in kidney function; a transplant case report advises other ways of measuring filtering. | Case reports and clinical trial Low certainty 10 13 12 4 | Tell the doctor or lab that you take CEE. |
| Medicines that affect the kidneys prescription | Not studied. | No interaction data for CEE were found in the sources read. | None found Not enough evidence | Ask a pharmacist. |
Who should check first 2
| Situation | Advice | Evidence |
|---|---|---|
| Kidney disease or a kidney transplant | A transplant case report found CEE raised creatinine and that normal graft checks were needed to sort it out. Ask a doctor first. | Case report 10 |
| Pregnancy, breastfeeding and children | No CEE data in these groups were found in the sources read. Ask a doctor or pharmacist. | None found |
Overdose, product quality and regulators
Summary. No toxicity study of CEE in people was found. The one marker that moved was blood creatinine.
Animal. Not reviewed.
Human doses studied. Trial amounts are in the studies table only.
Overdose response. Not found.
Genotoxicity. Not researched.
CEE-specific contamination data were not found. For products overall, one survey describes mixed forms and little third-party certification.
Blends and certification. About 21.7 percent of 175 creatine products were blends of forms and only 8 percent were third-party certified. 2
| Body | Action | Date |
|---|
When to get medical help
- Sudden swelling, very little urine, severe back or flank pain or new confusion: get medical care promptly and say what you take.
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 creatine ethyl ester?
A lab-made form of creatine with an ethyl group added. A 2022 review calls it a chemical alteration of creatine, not actually creatine.
Is creatine ethyl ester absorbed better than monohydrate?
Not in the one trial that measured it. Blood creatine was lower with CEE, and muscle creatine was no different from monohydrate.
Does CEE turn into creatinine?
Could CEE make my kidney blood test look abnormal?
Is creatine ethyl ester safe?
Do any trials favour CEE?
One 4-week trial of 40 soccer players did, on some tests. It was small and short, and one trial does not settle it.
Does CEE build more muscle than monohydrate?
Does CEE help thinking or memory?
Evidence is insufficient. One 2009 study reported gains on some tasks and needs repeating.
Does CEE avoid bloating?
Sellers claim so. The reviews we read found no evidence for that claim.
Is CEE a food or a natural product?
No. It is a lab-made form. Creatine itself is found in meat and fish.
Is the FDA's view of CEE known?
A 2022 review says notifications for CEE were filed in 2003 and for CEE hydrochloride in 2004, and that several creatine-form notifications drew FDA objections. We did not open the FDA records.
Are creatine products labelled accurately?
One survey found about 22 percent were blends of forms and only 8 percent were third-party certified. It did not test label accuracy.
Explore by health goal
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 started from our existing CEE summary, re-read PubMed abstracts for every trial, case report and review listed, and read the 2022 Kreider review in full via Europe PMC.
- 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. Some key review authors have creatine-industry ties, which is noted where it applies.
Sources 13
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Duan C, Wang Z, Wang Q. Creatine formulations and repeated sprint training: effects on physical and physiological adaptations in soccer players during the short-term preparation phase.. J Int Soc Sports Nutr. 2026. PMID 42720250. DOI 10.1080/15502783.2026.2721147. (abstract)
- Escalante G, Gonzalez AM, St Mart D, Torres M, Echols J, Islas M, Schoenfeld BJ. Analysis of the efficacy, safety, and cost of alternative forms of creatine available for purchase on Amazon.com: are label claims supported by science?. Heliyon. 2022. PMID 36544833. DOI 10.1016/j.heliyon.2022.e12113. (abstract)
- Fazio C, Elder CL, Harris MM. Efficacy of Alternative Forms of Creatine Supplementation on Improving Performance and Body Composition in Healthy Subjects: A Systematic Review.. J Strength Cond Res. 2022. PMID 36000773. DOI 10.1519/JSC.0000000000003873. (abstract)
- Giese MW, Lecher CS. Non-enzymatic cyclization of creatine ethyl ester to creatinine.. Biochem Biophys Res Commun. 2009. PMID 19660433. DOI 10.1016/j.bbrc.2009.07.151. (abstract)
- Gufford BT, Ezell EL, Robinson DH, Miller DW, Miller NJ, Gu X, Vennerstrom JL. pH-dependent stability of creatine ethyl ester: relevance to oral absorption.. J Diet Suppl. 2013. PMID 23957855. DOI 10.3109/19390211.2013.822453. (abstract)
- Jager R, Purpura M, Shao A, Inoue T, Kreider RB. Analysis of the efficacy, safety, and regulatory status of novel forms of creatine.. Amino Acids. 2011. PMID 21424716. DOI 10.1007/s00726-011-0874-6. (abstract)
- Katseres NS, Reading DW, Shayya L, Dicesare JC, Purser GH. Non-enzymatic hydrolysis of creatine ethyl ester.. Biochem Biophys Res Commun. 2009. PMID 19524547. DOI 10.1016/j.bbrc.2009.06.037. (abstract)
- Korovljev D, Ostojic J, Panic J, Ranisavljev M, Todorovic N, Nedeljkovic D, Kuzmanovic J, Vranes M, Stajer V, Ostojic SM. The Effects of 8-Week Creatine Hydrochloride and Creatine Ethyl Ester Supplementation on Cognition, Clinical Outcomes, and Brain Creatine Levels in Perimenopausal and Menopausal Women (CONCRET-MENOPA): A Randomized Controlled Trial.. J Am Nutr Assoc. 2026. PMID 40854087. DOI 10.1080/27697061.2025.2551184. (abstract)
- Kreider RB, Jager R, Purpura M. Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review.. Nutrients. 2022. PMID 35268011. DOI 10.3390/nu14051035. (full-text (Europe PMC))
- Law JP, Di Gerlando S, Pankhurst T, Kamesh L. Elevation of serum creatinine in a renal transplant patient following oral creatine supplementation.. Clin Kidney J. 2019. PMID 31384454. DOI 10.1093/ckj/sfy101. (abstract)
- Ling J, Kritikos M, Tiplady B. Cognitive effects of creatine ethyl ester supplementation.. Behav Pharmacol. 2009. PMID 19773644. DOI 10.1097/FBP.0b013e3283323c2a. (abstract)
- Spillane M, Schoch R, Cooke M, Harvey T, Greenwood M, Kreider R, Willoughby DS. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels.. J Int Soc Sports Nutr. 2009. PMID 19228401. DOI 10.1186/1550-2783-6-6. (abstract)
- Velema MS, de Ronde W. Elevated plasma creatinine due to creatine ethyl ester use.. Neth J Med. 2011. PMID 21411845. (abstract)
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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