Vitamins & Supplements · Antioxidant
Glutathione
Glutathione (GSH) · also called GSH, reduced glutathione, L-glutathione, glutatión
Glutathione is a small molecule your body makes in its own cells and is described as its most abundant natural antioxidant. It is also sold as capsules, under-the-tongue products and drips. Small trials show it can raise blood levels, but they do not show it improves health. Drips for skin lightening carry the most risk. Ask a doctor or pharmacist before use, especially during cancer treatment.
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 Glutathione
Glutathione is made by the body and also sold as a supplement. Trials show blood levels can rise, but health benefits are not shown, and drips carry the most risk.
What glutathione is
Glutathione is a small molecule made inside the body's cells. Researchers describe it as the body's most abundant natural antioxidant and a regulator of oxidative stress and immune function. It is not described as an essential nutrient, and no official recommended intake or upper limit was found.
Supplements come as capsules, tablets, under-the-tongue products, dissolving films and liquids called liposomal or micellar. Drips given into a vein are a separate medical topic. N-acetylcysteine (NAC) is a different compound.
Does a supplement raise glutathione?
In a 6-month placebo-controlled trial of 54 healthy adults, oral glutathione raised levels in red blood cells, plasma and white cells by about 30 to 35 percent at the higher amount, and in cheek cells much more. Levels went back to baseline a month after stopping.
One abstract says the gut breaks glutathione down, so food is not a major way to raise it. Small studies suggest some special forms give higher blood levels than a standard capsule. This is about absorption, not proven health benefit, and results for one product cannot be applied to another.
What the research shows
No trial read showed that glutathione prevents or treats a disease in healthy people. Small trials found a lab measure of immune cells rose, slightly lighter sun-exposed skin on a colour test, and better insulin sensitivity in 20 obese men. Each rests on one small study or on reviews of mixed quality.
Evidence is against drips for skin lightening and against a growth benefit in children with cystic fibrosis, and insufficient for acne and Parkinson's disease.
Food versus pills
No food amounts for glutathione were read, so none are given. Trial results above are for supplements. No trial compared food with pills.
At a glance
Traditional uses history, not proof
- A compound the body makes for itself
- Marketed as a supplement for skin lightening, immunity and general antioxidant support
Studied for research
- Body-made antioxidant role, high certainty
- Raising blood and cell levels, low certainty
- Skin colour (oral and topical), low certainty
- Immune lab marker and cystic fibrosis growth, low certainty
- Insulin sensitivity, fatty liver, COPD and gut bacteria, very low certainty
- Acne and Parkinson's disease, insufficient evidence
- Skin lightening by drip, evidence against
Main compounds
- Reduced glutathione (GSH)
- Oxidised glutathione (GSSG)
- Liposomal, micellar, sublingual and film forms
Common forms
- Capsules and tablets
- Liposomal and micellar liquids
- Under-the-tongue products and dissolving films
- Topical products
- Intravenous drips (medical or cosmetic settings)
Research links: 2015 randomised trial: oral glutathione and body stores (54 adults) · 2019 systematic review: glutathione and skin colour · 2025 systematic review: glutathione as a skin-lightening agent and in melasma · 2025 case report: reaction after a cosmetic glutathione drip · 2025 systematic review: antioxidants during radiotherapy · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Glutathione (GSH), a small molecule made of three amino acids, made by the body's cells
- Common names
- Glutathione (English); GSH (English); Reduced glutathione (English); L-glutathione (English); Glutatión (Spanish)
- Family or group
- A thiol tripeptide (three amino acids joined, with a sulphur group) that works as an antioxidant. The three amino acids are glutamate, cysteine and glycine according to our existing summary and PubChem's chemical name; no abstract read spells this out.
- Look-alikes and adulterants
- Name: N-acetylcysteine (NAC); Note: A different compound that supplies cysteine, one of the building blocks. It has its own page.; Name: Glutathione disulfide (GSSG); Note: The used, oxidised form. Trials report the ratio of reduced to oxidised glutathione as a marker.
- 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 |
|---|---|---|---|---|
| Reduced glutathione (GSH) PubChem 124886 | thiol tripeptide | Not read from a source. | The active, reduced form that works as an antioxidant. PubChem CID and formula checked through the PubChem web service on 2026-10-26. 21 14 | Human data |
| Oxidised glutathione (GSSG) PubChem 65359 | disulfide of glutathione | Not read from a source. | The used form. Its ratio to reduced glutathione is a lab marker of oxidative stress in trials. 21 14 | Human data |
| Supplement forms: standard capsule, liposomal, micellar, sublingual, orobuccal tablet, dissolving film, topical oxidised glutathione | delivery forms | Not applicable | Compared by blood levels in small studies; see the Benefits tab. 3 16 18 10 5 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Antioxidant defence and redox balance in cells | Not specified in the abstracts | Described in trial abstracts as the most abundant natural antioxidant and a regulator of oxidative stress and immune function. 14 | Human data |
| Breakdown in the gut | Gamma-glutamyltransferase (an intestinal enzyme) | One abstract says the gut enzyme breaks glutathione down, so dietary glutathione is not a major way to raise it. Another paper calls the amount reaching the blood after swallowing controversial. 3 10 | Human data |
| Absorption through the mouth lining | Not specified | A reconstructed mouth-lining lab model absorbed glutathione over time, and volunteers' blood levels rose within 30 to 60 minutes of a mouth-lining tablet. 3 | In vitro and human |
| Skin pigment production | Tyrosinase (the pigment enzyme) | The proposed idea is that glutathione blocks tyrosinase and shifts pigment production toward a lighter type. The review says translating this into clear skin results is uncertain. 1 | Hypothesis |
| Antioxidant enzymes in blood | SOD3 and GPX1 | Both enzymes rose in both groups in a COPD study; the difference between groups was not significant. 6 | Human biomarker |
| Reductive stress | Not specified | A 2026 review raises a possible risk of too much reducing power from antioxidant supplementation and says it should be studied. It is not shown in people. 4 | Hypothesis |
Absorption, metabolism and elimination
- Absorption
- Debated. One abstract says the gut breaks glutathione down; another calls the amount reaching the blood controversial. Special forms (liposomal, micellar, sublingual, film) gave higher blood levels in small single-product studies.
- Distribution
- Not covered by the abstracts read.
- Metabolism
- Gut enzymes break it down (one abstract).
- Elimination
- Not covered.
- Bioavailability
- Varies by form and product. In one crossover study a micellar form gave about 2.5 times the blood exposure of a standard form at the amounts used.
Isolated compounds versus whole extracts
Food glutathione and supplement glutathione are different questions. One abstract says the gut breaks down glutathione from food, so food is not a major way to raise levels. No food amounts or food trials were read for this page.
Nutritional composition
No USDA FoodData Central or NIH figures for glutathione in foods were read, so none are stated.
1 high certainty6 low certainty4 very low certainty2 not enough evidence1 evidence against
What was looked at
The 14 benefits and uses checked for Glutathione, each with how strong the evidence is. Tap one to open it.
- A compound the body makes for itselfHigh certainty
- Raising glutathione levels in blood and cellsLow certainty
- Capsule, liposomal, under-the-tongue and film formsLow certainty
- Skin colour (oral and topical use)Low certainty
- Skin lightening by drip (intravenous)Evidence against
- Immune cell activity (lab marker)Low certainty
- Insulin sensitivity in obese menVery low certainty
- Gut bacteria in type 2 diabetesVery low certainty
- Fatty liver disease (liver enzyme)Very low certainty
- Chronic lung disease (COPD) markersVery low certainty
- Growth in children with cystic fibrosisLow certainty
- AcneNot enough evidence
- Parkinson's disease (drip and nasal use)Not enough evidence
- During cancer treatment (radiotherapy)Low certainty
Lab markers tracked in the studies
Glutathione in blood and cellsReduced-to-oxidised glutathione ratio (GSH/GSSG)Skin melanin indexNatural killer cell activityALT (liver enzyme)Insulin sensitivity (clamp test)IL-8 and TNF-alpha (inflammation markers)Weight-for-age z-score
What is Glutathione good for?
The main studied uses and how strong the human evidence is for each. A normal job in the body is not proof that extra supplements add benefit.
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.
A compound the body makes for itself
High certaintyGlutathione is made inside the body's cells. Researchers describe it as the body's most abundant natural antioxidant and a regulator of oxidative stress and immune function. It is not a vitamin you must get from food.
2 studiesNot applicable here; forms are discussed in the card on supplement fo…
Studies, doses and limits
What the trials found
The abstracts of two human papers describe glutathione as the most abundant natural antioxidant and as a regulator of oxidative stress and immune function.
Results
Glutathione has a real job in the body. That does not show that swallowing more of it helps health. No official recommended intake or upper limit was found for it.
Effect sizes as reported
No effect sizes apply: this is a role in the body, not a trial result.
Why this rating
High that the body makes glutathione and uses it as an antioxidant (stated in trial and review abstracts). That is separate from any supplement benefit, which is rated in the cards below.
Who was studied
Everyone; the body makes it.
Limits
Role statements come from abstracts, not from a primary biochemistry source read in full.
Why researchers looked
People ask whether a supplement can add to something the body already makes.
Traditional use
Not a traditional remedy. It is a modern supplement ingredient.
Proposed mechanism Established biology
Glutathione helps cells handle oxidative stress. This is established biology; being an antioxidant in cells does not show that a pill prevents disease.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for what is known about supplements.
Raising glutathione levels in blood and cells
Low certaintyIn one 6-month trial in healthy adults, glutathione capsules raised glutathione in blood cells and cheek cells. Levels went back to the starting point a month after stopping. A higher blood level is a lab number, not a health benefit.
4 studiesPlain capsules and special forms were both tested; see the next card.
Studies, doses and limits
What the trials found
A 54-person placebo-controlled trial found rises in several blood compartments over 6 months. Two smaller trials of different forms also found rises over 3 to 4 weeks, but they tested particular products.
Results
Oral glutathione raised blood and cell levels in short trials in healthy adults. This shows the number can change. It does not show any illness prevented or symptom relieved.
Effect sizes as reported
Red cell, plasma and lymphocyte glutathione up about 30 to 35 percent in the high-amount group at 6 months; cheek cells up 260 percent.
Why this rating
Low because the best trial is one study of 54 people measuring a lab marker, and the other trials are very small and test branded products. Higher levels have not been linked to better health in these trials.
Form and dose studied
Plain capsules and special forms were both tested; see the next card.
Who was studied
Healthy adults, and in one small study people with metabolic syndrome.
Limits
Lab marker only. Short trials. Healthy people with normal glutathione. Some of the products tested are branded.
Why researchers looked
The first question for any glutathione pill is whether it changes levels in the body at all.
Proposed mechanism Human biomarker
Levels in blood rose in trials. How much of the swallowed glutathione is absorbed whole is still debated; one abstract says the gut breaks it down.
A proposed mechanism does not show that the effect happens in people.
No harm signals in these short trials; see the Safety tab.
Capsule, liposomal, under-the-tongue and film forms
Low certaintySmall studies compare forms of glutathione by how much appears in the blood after a dose. Some special forms gave higher blood levels than a standard capsule. None of these studies tested whether people got healthier.
5 studiesStandard capsule, liposomal, micellar, sublingual and orally dissolvi…
Studies, doses and limits
What the trials found
Four small human studies compared forms: a mouth-lining tablet (15 people, no comparison group), a sublingual form against oral glutathione and NAC (20 people with metabolic syndrome), a micellar form against standard and liposomal capsules (14 people), and a dissolving film against a tablet. A 2026 review says better delivery has not been shown to bring meaningful benefit.
Results
Some special forms raised blood glutathione more than standard capsules in single-product studies. That is about absorption, not health. Results for one product cannot be applied to another.
Effect sizes as reported
Micellar form about 2.5 times the blood exposure of the standard form (14 people); sublingual form higher GSH/GSSG ratio than oral glutathione, p = 0.003.
Why this rating
Low: small studies, each testing one product, some branded, measuring blood levels only. A 2026 systematic review says benefit from better delivery is not shown.
Form and dose studied
Standard capsule, liposomal, micellar, sublingual and orally dissolving film were studied.
Who was studied
Healthy adults, and 20 people with metabolic syndrome.
Limits
Tiny samples, short follow-up, branded products, possible maker links. No health outcomes.
Why researchers looked
Because ordinary glutathione is partly broken down in the gut, makers sell special forms and people ask if they work better.
Proposed mechanism Pharmacokinetic
Special forms are meant to get glutathione into the blood intact. One abstract says the gut enzyme gamma-glutamyltransferase breaks glutathione down, and lab work showed absorption through mouth lining.
A proposed mechanism does not show that the effect happens in people.
Short trials of these forms reported no adverse events or no changes in liver and kidney markers; see the Safety tab.
Skin colour (oral and topical use)
Low certaintyGlutathione is widely sold in parts of Asia as a skin-lightening supplement. Small trials in healthy volunteers found a lower skin melanin index in sun-exposed skin with oral or topical glutathione, but reviewers call the evidence inconclusive.
2 studiesOral and topical forms (oral amounts studied are listed in the Eviden…
Studies, doses and limits
What the trials found
A 2019 systematic review of 4 studies in healthy volunteers and a 2025 systematic review of trials (5 randomised oral trials and one open-label study) both reported a lower melanin index than placebo. The 2019 authors called the evidence inconclusive; the 2025 authors call the effects moderate but unsustainable.
Results
Skin in sun-exposed areas looked a little lighter on a skin-colour measurement in several small trials. Sun-protected skin did not change clearly. Studies were of mixed quality, the effect fades when treatment stops, and this is a cosmetic result, not a health benefit.
Effect sizes as reported
No pooled numbers in the abstracts.
Why this rating
Low: several small placebo-controlled trials point the same way, but both reviews report mixed or inconsistent study quality and one calls the evidence inconclusive.
Form and dose studied
Oral and topical forms (oral amounts studied are listed in the Evidence tab).
Who was studied
Healthy volunteers; not people with a pigment disorder such as melasma (the 2025 review also covers melasma).
Limits
Small trials, mixed risk of bias, short follow-up, effect not lasting. Some non-serious side effects were reported.
Why researchers looked
Skin-lightening is the best-known marketing use of glutathione.
Traditional use
Marketing use, not a traditional remedy.
Proposed mechanism Hypothesis
In lab studies glutathione is said to block the enzyme tyrosinase and shift pigment production. This is a hypothesis; the trials measure skin colour, not that mechanism.
A proposed mechanism does not show that the effect happens in people.
Non-serious side effects were reported; see the Safety tab.
Skin lightening by drip (intravenous)
Evidence againstGlutathione drips are sold for skin lightening. A 2025 systematic review found only one placebo-controlled trial, with a result that was not statistically significant, and says IV use is contraindicated. Serious reactions have been reported.
3 studiesIntravenous only.
Studies, doses and limits
What the trials found
One placebo-controlled IV trial was found: 6 of 16 improved with glutathione and 3 of 16 with placebo (p 0.054). A 2026 narrative review says evidence is too limited to justify routine cosmetic use and notes vitamin C is often given at the same time.
Results
There is no good evidence that drips lighten skin, and reviewers raise safety concerns. A case report describes a collapse with fever and liver injury within an hour of an unregulated drip.
Effect sizes as reported
6 of 16 versus 3 of 16, p = 0.054 (one trial).
Why this rating
Against: the one controlled trial did not reach statistical significance, two reviews say it is not justified or is contraindicated, and harms have been reported. This rating is about cosmetic use of drips.
Form and dose studied
Intravenous only.
Who was studied
Adults seeking skin lightening.
Limits
One small trial; vitamin C is often given too; unregulated products vary.
Why researchers looked
Drips and injections are marketed as a faster route than capsules.
Traditional use
Marketing use, not a traditional remedy.
Proposed mechanism Hypothesis
The idea is the same as for oral use, that glutathione affects pigment production; this remains unproven in people.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab: this is the highest-risk use.
Immune cell activity (lab marker)
Low certaintyIn the 6-month trial of healthy adults, a lab measure of immune cells, natural killer cell activity, more than doubled with the high amount at 3 months. Nobody counted infections, so a real-world immune benefit is not shown.
1 studiesOral glutathione capsules.
Studies, doses and limits
What the trials found
One placebo-controlled trial measured natural killer cell cytotoxicity in a subset of its 54 healthy adults.
Results
A lab measure of immune cell activity went up in one trial. It was not linked to fewer colds or infections.
Effect sizes as reported
Natural killer cell cytotoxicity more than doubled versus placebo in the high-amount group at 3 months (P < 0.05).
Why this rating
Low: one trial, measured in a subset, lab marker only.
Form and dose studied
Oral glutathione capsules.
Who was studied
Healthy non-smoking adults.
Limits
Subset of participants; no infection outcomes; not repeated.
Why researchers looked
Glutathione is described as a regulator of immune function, so trials checked immune markers.
Proposed mechanism Human biomarker
Not established. The trial measured a lab marker only.
A proposed mechanism does not show that the effect happens in people.
None reported.
Insulin sensitivity in obese men
Very low certaintyIn a small 3-week trial of 20 obese men, with and without type 2 diabetes, insulin sensitivity measured by a clamp test rose with oral glutathione. Oxidative stress markers did not change, and the study needs repeating.
1 studiesOral reduced glutathione.
Studies, doses and limits
What the trials found
One randomised, placebo-controlled trial of 20 men, 10 with type 2 diabetes.
Results
Insulin sensitivity improved in the glutathione group over 3 weeks. It is one very small trial, and the authors say oxidative stress markers did not change.
Effect sizes as reported
Insulin sensitivity rose significantly in the glutathione group; muscle glutathione about +19 percent (not significant).
Why this rating
Very low: 20 men, 3 weeks, one study, no repeat, and no clear mechanism.
Form and dose studied
Oral reduced glutathione.
Who was studied
Obese men, with or without type 2 diabetes.
Limits
Tiny sample; short; men only.
Why researchers looked
Researchers tested whether an antioxidant supplement changes how the body handles sugar.
Proposed mechanism Human biomarker
Unclear. Muscle glutathione rose about 19 percent but not significantly, and the oxidative-stress markers measured did not change, so the reason for the effect is unknown.
A proposed mechanism does not show that the effect happens in people.
People using glucose-lowering medicines should ask a pharmacist; see the Safety tab.
Gut bacteria in type 2 diabetes
Very low certaintyA follow-up of a 6-month trial in people with type 2 diabetes found changes in gut bacteria with oral glutathione. These are lab counts of bacteria, not health results.
1 studiesOral glutathione alongside diabetes treatment.
Studies, doses and limits
What the trials found
A secondary analysis of a randomised trial using stool sequencing.
Results
Some bacteria groups rose and Escherichia/Shigella fell. The authors read this as a healthier mix, but bacteria counts are not symptoms or outcomes.
Effect sizes as reported
P < 0.05 for the named changes; no counts in the abstract.
Why this rating
Very low: a secondary lab analysis, size not given in the abstract, no clinical outcome.
Form and dose studied
Oral glutathione alongside diabetes treatment.
Who was studied
Indian adults with type 2 diabetes.
Limits
Bacteria changes are not clinical outcomes; the HbA1c result belongs to an earlier paper not read here.
Why researchers looked
Researchers asked whether glutathione changes the gut bacteria mix in diabetes.
Proposed mechanism Human biomarker
Not established.
A proposed mechanism does not show that the effect happens in people.
None reported in the abstract.
Fatty liver disease (liver enzyme)
Very low certaintyA small single-arm pilot of 29 finishers found the liver enzyme ALT fell after 4 months of oral glutathione that followed a 3-month lifestyle programme. With no placebo group, the drop cannot be credited to glutathione.
1 studiesOral glutathione.
Studies, doses and limits
What the trials found
One open-label pilot with no control group.
Results
ALT, triglycerides and ferritin went down. Because everyone got glutathione after a lifestyle programme, other causes cannot be ruled out.
Effect sizes as reported
ALT fell significantly (no numbers in the abstract); liver-fat measure fell only in people whose ALT dropped.
Why this rating
Very low: single-arm pilot with no placebo, 5 dropouts.
Form and dose studied
Oral glutathione.
Who was studied
Adults with fatty liver disease.
Limits
No control group; lifestyle programme first; small.
Why researchers looked
Glutathione drips have long been used for liver conditions, so an oral pilot was run.
Proposed mechanism Human biomarker
Not established.
A proposed mechanism does not show that the effect happens in people.
None reported in the abstract.
Chronic lung disease (COPD) markers
Very low certaintyIn 50 people with COPD, adding glutathione under the tongue to usual treatment did not give a statistically significant difference in inflammation markers compared with usual treatment alone.
1 studiesSublingual glutathione added to formoterol.
Studies, doses and limits
What the trials found
One small controlled study.
Results
Inflammation markers fell in both groups. The difference between groups was not significant. No symptom or flare-up results were reported.
Effect sizes as reported
No numbers in the abstract; between-group P > 0.05.
Why this rating
Very low: 50 people, blood markers only, no clear difference.
Form and dose studied
Sublingual glutathione added to formoterol.
Who was studied
People with COPD.
Limits
Small; markers only; how people were assigned is not stated.
Why researchers looked
Researchers tested whether an antioxidant add-on changes inflammation and antioxidant markers in COPD.
Proposed mechanism Human biomarker
Blood antioxidant enzymes (SOD3, GPX1) rose in both groups.
A proposed mechanism does not show that the effect happens in people.
None reported in the abstract.
Growth in children with cystic fibrosis
Low certaintyA 24-week trial in 58 children with cystic fibrosis found no difference in growth or inflammation markers between glutathione and placebo.
1 studiesOral reduced glutathione.
Studies, doses and limits
What the trials found
One multicentre, placebo-controlled, double-blind phase II trial.
Results
Growth did not differ from placebo and glutathione was well tolerated.
Effect sizes as reported
Weight-for-age z-score difference -0.08 (95% CI -0.22 to 0.06; P = 0.25).
Why this rating
Low certainty that it does not help growth: one well-run but small trial in a single rare condition.
Form and dose studied
Oral reduced glutathione.
Who was studied
Children aged 2 to 10 with cystic fibrosis and pancreatic insufficiency.
Limits
Small; one condition; does not apply to healthy children.
Why researchers looked
Inflammation in the gut may hurt nutrition in cystic fibrosis, so glutathione was tried to help growth.
Proposed mechanism Human clinical
Not shown.
A proposed mechanism does not show that the effect happens in people.
Described as safe and well tolerated in this trial.
Acne
Not enough evidenceIn 40 people with mild to moderate acne, 4 weeks of oral glutathione did not significantly lower blood inflammation markers. Seven of 22 moved from moderate to mild acne.
1 studiesOral glutathione.
Studies, doses and limits
What the trials found
One small randomised trial.
Results
No significant change in markers. A third of the glutathione group improved a grade, but the abstract does not give the placebo group's result, so this cannot be called an effect.
Effect sizes as reported
7 of 22 (31.8 percent) improved a grade; marker changes not significant (P > 0.05).
Why this rating
Insufficient: one small, short trial with non-significant results.
Form and dose studied
Oral glutathione.
Who was studied
People with mild to moderate acne.
Limits
Small; short; the abstract does not report placebo acne results.
Why researchers looked
The authors say oxidative stress contributes to acne, so glutathione was tried.
Proposed mechanism Human clinical
Not established.
A proposed mechanism does not show that the effect happens in people.
No adverse reactions were reported.
Parkinson's disease (drip and nasal use)
Not enough evidenceSmall trials of glutathione given by drip or nose in Parkinson's disease found no significant benefit. A 2026 review calls the glutathione findings inconclusive. These were not capsules.
2 studiesIntravenous or intranasal glutathione, not oral.
Studies, doses and limits
What the trials found
A 21-person placebo-controlled IV pilot and a 9-study systematic review (196 people).
Results
No significant difference in symptom scores with IV glutathione; intranasal glutathione only modestly raised brain levels. NAC, a different compound, did better in the review.
Effect sizes as reported
UPDRS 2.8 units better during treatment (P = 0.32), 3.5 units worse over the next 8 weeks (P = 0.54).
Why this rating
Insufficient: small pilot and short studies with different routes.
Form and dose studied
Intravenous or intranasal glutathione, not oral.
Who was studied
People with Parkinson's disease.
Limits
Small studies; not capsules.
Why researchers looked
Researchers think low glutathione contributes to nerve cell damage in Parkinson's disease, so replacing it was tried.
Proposed mechanism Hypothesis
The idea is oxidative stress lowers glutathione in brain cells. Whether swallowed or infused glutathione reaches the brain in useful amounts is unproven.
A proposed mechanism does not show that the effect happens in people.
The IV pilot reported no safety concerns under clinical supervision.
During cancer treatment (radiotherapy)
Low certaintyA 2025 systematic review found glutathione-enhanced treatment helped people keep to radiotherapy but did not give significant protection against side effects. It also warned that antioxidants in general may weaken cancer treatment.
1 studiesGlutathione among many antioxidants.
Studies, doses and limits
What the trials found
One systematic review covering many antioxidants.
Results
No clear protection from side effects. Several studies suggested antioxidants may reduce tumour control. The authors say clinical recommendations are premature.
Effect sizes as reported
No numbers in the abstract.
Why this rating
Low: the abstract gives little glutathione-specific detail.
Form and dose studied
Glutathione among many antioxidants.
Who was studied
People having radiotherapy.
Limits
Review covers many antioxidants; glutathione studies not itemised in the abstract.
Why researchers looked
Antioxidants are studied to reduce radiation side effects.
Proposed mechanism Hypothesis
Radiotherapy works partly by making free radicals, so antioxidants might also protect cancer cells. This is a concern raised by the reviewers.
A proposed mechanism does not show that the effect happens in people.
Ask the oncology team before any supplement; see the Safety tab.
Connections to the rest of health
How Glutathione 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 |
|---|---|---|---|---|
| Cellular Protection | High certainty | A compound the body makes for itself: Glutathione is made inside the body's cells. Researchers describe it as the body's most abundant natural antioxidant and a regulator of oxidative stress and immune function. It is not a vitamin you must get from food. | 14 3 | |
| Cellular Protection | Low certainty | Raising glutathione levels in blood and cells: In one 6-month trial in healthy adults, glutathione capsules raised glutathione in blood cells and cheek cells. Levels went back to the starting point a month after stopping. A higher blood level is a lab number, not a health benefit. | 14 10 18 16 | |
| Cellular Protection | Low certainty | Capsule, liposomal, under-the-tongue and film forms: Small studies compare forms of glutathione by how much appears in the blood after a dose. Some special forms gave higher blood levels than a standard capsule. None of these studies tested whether people got healthier. | 3 16 18 10 4 | |
| Healthy Skin | Low certainty | Skin colour (oral and topical use): Glutathione is widely sold in parts of Asia as a skin-lightening supplement. Small trials in healthy volunteers found a lower skin melanin index in sun-exposed skin with oral or topical glutathione, but reviewers call the evidence inconclusive. Skin lightening by drip (intravenous): Glutathione drips are sold for skin lightening. A 2025 systematic review found only one placebo-controlled trial, with a result that was not statistically significant, and says IV use is contraindicated. Serious reactions have been reported. | 5 15 1 17 | |
| Immune Support | Low certainty | Immune cell activity (lab marker): In the 6-month trial of healthy adults, a lab measure of immune cells, natural killer cell activity, more than doubled with the high amount at 3 months. Nobody counted infections, so a real-world immune benefit is not shown. | 14 | |
| Blood Sugar Balance | Very low certainty | Insulin sensitivity in obese men: In a small 3-week trial of 20 obese men, with and without type 2 diabetes, insulin sensitivity measured by a clamp test rose with oral glutathione. Oxidative stress markers did not change, and the study needs repeating. | 19 | |
| Metabolic Health | Very low certainty | Insulin sensitivity in obese men: In a small 3-week trial of 20 obese men, with and without type 2 diabetes, insulin sensitivity measured by a clamp test rose with oral glutathione. Oxidative stress markers did not change, and the study needs repeating. | 19 | |
| Gut Health | Very low certainty | Gut bacteria in type 2 diabetes: A follow-up of a 6-month trial in people with type 2 diabetes found changes in gut bacteria with oral glutathione. These are lab counts of bacteria, not health results. | 7 | |
| Blood Sugar Balance | Very low certainty | Gut bacteria in type 2 diabetes: A follow-up of a 6-month trial in people with type 2 diabetes found changes in gut bacteria with oral glutathione. These are lab counts of bacteria, not health results. | 7 | |
| Liver Support | Very low certainty | Fatty liver disease (liver enzyme): A small single-arm pilot of 29 finishers found the liver enzyme ALT fell after 4 months of oral glutathione that followed a 3-month lifestyle programme. With no placebo group, the drop cannot be credited to glutathione. | 9 | |
| Lung Support | Very low certainty | Chronic lung disease (COPD) markers: In 50 people with COPD, adding glutathione under the tongue to usual treatment did not give a statistically significant difference in inflammation markers compared with usual treatment alone. | 6 | |
| Metabolic Health | Low certainty | Growth in children with cystic fibrosis: A 24-week trial in 58 children with cystic fibrosis found no difference in growth or inflammation markers between glutathione and placebo. | 2 | |
| Healthy Skin | Not enough evidence | Acne: In 40 people with mild to moderate acne, 4 weeks of oral glutathione did not significantly lower blood inflammation markers. Seven of 22 moved from moderate to mild acne. | 12 | |
| Healthy Aging | Not enough evidence | Parkinson's disease (drip and nasal use): Small trials of glutathione given by drip or nose in Parkinson's disease found no significant benefit. A 2026 review calls the glutathione findings inconclusive. These were not capsules. | 8 13 | |
| Cellular Protection | Low certainty | During cancer treatment (radiotherapy): A 2025 systematic review found glutathione-enhanced treatment helped people keep to radiotherapy but did not give significant protection against side effects. It also warned that antioxidants in general may weaken cancer treatment. | 11 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Whole Body | Biological association | High certainty | Studied for: A compound the body makes for itself Studied for: Raising glutathione levels in blood and cells | 14 3 10 18 16 4 11 |
| Immune System | Biological association | High certainty | Studied for: A compound the body makes for itself Studied for: Immune cell activity (lab marker) | 14 3 |
| Skin Hair Beauty | Biological association | Low certainty | Studied for: Skin colour (oral and topical use) Studied for: Skin lightening by drip (intravenous) | 5 15 1 17 12 |
| Endocrine System | Biological association | Very low certainty | Studied for: Insulin sensitivity in obese men | 19 |
| Metabolism Weight | Biological association | Very low certainty | Studied for: Insulin sensitivity in obese men | 19 |
| Digestive System | Biological association | Very low certainty | Studied for: Gut bacteria in type 2 diabetes Studied for: Growth in children with cystic fibrosis | 7 2 |
| Hepatic System | Biological association | Very low certainty | Studied for: Fatty liver disease (liver enzyme) | 9 |
| Respiratory System | Biological association | Very low certainty | Studied for: Chronic lung disease (COPD) markers | 6 |
| Nervous System | Biological association | Not enough evidence | Studied for: Parkinson's disease (drip and nasal use) | 8 13 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Glutathione in blood and cells | Biological association | Low certainty | Measured in trials: higher in trials. A lab change is not the same as a health benefit. | 14 10 |
| Reduced-to-oxidised glutathione ratio (GSH/GSSG) | Biological association | Low certainty | Measured in trials: improved in some trials. A lab change is not the same as a health benefit. | 14 16 18 |
| Skin melanin index | Biological association | Low certainty | Measured in trials: lower in sun-exposed skin in several small trials. A lab change is not the same as a health benefit. | 5 15 |
| Natural killer cell activity | Biological association | Low certainty | Measured in trials: higher in one trial. A lab change is not the same as a health benefit. | 14 |
| ALT (liver enzyme) | Biological association | Very low certainty | Measured in trials: lower in a single-arm pilot. A lab change is not the same as a health benefit. | 9 |
| Insulin sensitivity (clamp test) | Biological association | Very low certainty | Measured in trials: higher in one small trial. A lab change is not the same as a health benefit. | 19 |
| IL-8 and TNF-alpha (inflammation markers) | Biological association | Very low certainty | Measured in trials: fell in both groups, no clear difference. A lab change is not the same as a health benefit. | 6 |
| Weight-for-age z-score | Biological association | Low certainty | Measured in trials: no difference. A lab change is not the same as a health benefit. | 2 |
K. Biological pathways
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| N-acetylcysteine (NAC) | Preliminary mechanism | Human | Supplies cysteine, a building block of glutathione. Compared with glutathione in one small crossover study. | 16 |
| GSH/GSSG redox ratio | Preliminary mechanism | Human | The lab ratio used in trials as a measure of oxidative stress. | 14 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Reduced glutathione (GSH) | Biological association | Human | The active, reduced form that works as an antioxidant. PubChem CID and formula checked through the PubChem web service on 2026-10-26. | 21 14 |
| Oxidised glutathione (GSSG) | Biological association | Human | The used form. Its ratio to reduced glutathione is a lab marker of oxidative stress in trials. | 21 14 |
| Supplement forms: standard capsule, liposomal, micellar, sublingual, orobuccal tablet, dissolving film, topical oxidised glutathione | Biological association | Human | Compared by blood levels in small studies; see the Benefits tab. | 3 16 18 10 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 14 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 Glutathione. 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 glutathione summary, looked up the chemistry in PubChem and re-read PubMed abstracts for trials, reviews and a case report. Only abstracts were read. Official NIH fact sheets were not found or were blocked, and are marked unread.
Study library: every study we checked 21
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Aloraini 2026 Glutathione for skin lightening via intravenous, oral, and topical routes: a critical narrative review of current evidence, safety, and the evidence-practice gap. J Med Life · PMID 42751591 · DOI |
Narrative review |
Mechanism, preclinical and clinical studies of glutathione for skin lightening (searched to March 2026) | Glutathione, mainly intravenous IV, oral, topical |
The review found limited evidence of modest, varied improvement in pigmentation. Studies were small, used different methods and had short follow-up. Vitamin C is often given with IV glutathione, so the effect of glutathione alone is unclear. The authors describe new safety concerns: liver toxicity, allergic reactions, and possible kidney and hormone effects. They conclude evidence is too limited to justify routine cosmetic use. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Efficacy and safety of IV glutathione for cosmetic skin lightening Limitations: A narrative review, so studies were not pooled; the safety signals are concerns raised in the literature, not rates. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Bozic 2020 Oral Glutathione and Growth in Cystic Fibrosis: A Multicenter, Randomized, Placebo-controlled, Double-blind Trial. J Pediatr Gastroenterol Nutr · PMID 32960827 · DOI |
Randomised controlled trial |
58 58 children aged 2 to 10 with cystic fibrosis and pancreatic insufficiency (30 glutathione, 28 placebo) |
Reduced glutathione by mouth Oral supplement 24 weeks · vs Placebo |
No significant difference between glutathione and placebo in weight-for-age z-score, weight or BMI, and none in the other secondary outcomes, including blood and stool inflammation markers. The authors called glutathione safe and well tolerated. Weight-for-age z-score difference -0.08 (95% CI -0.22 to 0.06; P = 0.25) Methods, limits and fundingOutcomes: Change in weight-for-age z-score; other growth measures; inflammation markers Limitations: Phase II trial in one rare condition; says nothing about healthy children. Funding and conflicts: Research support is listed as non-US government; Not stated in the abstract. Read: abstract |
| Buonocore 2016 Bioavailability Study of an Innovative Orobuccal Formulation of Glutathione. Oxid Med Cell Longev · PMID 26649136 · DOI |
Pharmacokinetic study |
15 15 healthy volunteers (plus a lab model of mouth lining) |
Glutathione in a branded fast-slow release tablet held in the mouth Orobuccal (mouth-lining) tablet Short single-dose test |
The lab model showed glutathione was absorbed through reconstructed mouth lining over time. In the volunteers blood glutathione rose within 30 and 60 minutes. The authors wrote that the gut breaks glutathione down, so dietary glutathione is not a major way to raise it. No numbers in the abstract (Not reported in the abstract) Methods, limits and fundingOutcomes: Glutathione blood level after dosing; absorption through reconstructed mouth lining in the lab Limitations: Very small, short; a blood level, not a health result; one branded product, so it says nothing about other products. Funding and conflicts: Research support is listed as non-US government; product maker involvement not stated in the abstract. Read: abstract |
| Carnib 2026 Glutathione in redox homeostasis: Bridging molecular mechanisms, bioavailability constraints, and translational challenges in systemic therapeutics. Biomed Pharmacother · PMID 42585816 · DOI |
Systematic review |
Published glutathione research from 2004 to 2025, systematic review with research-mapping | Glutathione, with liposomal, intranasal and sublingual delivery systems Various |
The authors say clinical use is held back by low oral absorption and rapid breakdown. Newer delivery forms may improve stability and blood availability, but evidence that this brings meaningful benefit is limited. Current findings support the biology and pharmacokinetics rather than proven treatment effect. They also raise a possible risk of reductive stress, which they present as a point to study. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Pharmacokinetic barriers and whether better delivery leads to clinical benefit Limitations: A review and mapping exercise; the abstract does not give study counts or safety rates. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Dilokthornsakul 2019 The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. J Cosmet Dermatol · PMID 30895708 · DOI |
Systematic review |
4 studies in healthy volunteers (3 placebo-controlled trials, 1 single-arm trial) | Glutathione, oral (3 studies) or topical oxidised glutathione (1 study) Oral and topical Oral studies used 250 to 500 mg a day (amounts studied, not advice); topical 2 percent · vs Placebo in three studies |
Oral glutathione at the higher amount and the 2 percent topical form lightened skin in sun-exposed areas by the melanin index. No clear difference in sun-protected areas. There was a trend toward better wrinkles, elasticity and UV spots. Some non-serious side effects were reported. The authors called the evidence inconclusive because of study quality and inconsistent findings. No pooled numbers in the abstract (Not reported in the abstract) Methods, limits and fundingOutcomes: Skin melanin index (a skin colour measure), wrinkles, elasticity, UV spots, side effects Limitations: Only 4 small studies, mixed quality; healthy volunteers rather than people with a pigment condition; searched up to October 2017. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Farag 2023 Evaluation of the antioxidant and anti-inflammatory effect of sublingual glutathione on COPD patients. J Med Life · PMID 38585534 · DOI |
Controlled trial |
50 50 people with chronic obstructive pulmonary disease (COPD) |
Glutathione under the tongue added to usual treatment (formoterol inhaler) Sublingual 300 mg twice a day (amount studied, not advice) 2 months · vs Usual treatment alone |
Both groups had lower inflammation markers (IL-8, TNF-alpha) than their own starting levels, but the difference between the groups was not statistically significant. Antioxidant enzyme markers (SOD3, GPX1) rose in both groups. The abstract says they were higher with glutathione, but gives P above 0.05 for that comparison. No numbers in the abstract (P > 0.05 between groups) Methods, limits and fundingOutcomes: Serum IL-8, TNF-alpha, SOD3 and GPX1 Limitations: Small; blood markers only, no symptoms or flare-ups; how people were assigned is not stated in the abstract. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Gaike 2023 Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals. FEMS Microbiol Lett · PMID 37935462 · DOI |
Randomised controlled trial secondary analysis |
Indian adults with type 2 diabetes from a randomised trial | Glutathione by mouth, alongside diabetes treatment Oral supplement 500 mg once a day (amount studied, not advice) 6 months · vs Diabetes treatment without glutathione |
Proteobacteria fell and some groups of bacteria (Megasphaera, Bacteroides, Megamonas) rose, while Escherichia/Shigella fell. The authors read this as restoring a healthier gut mix. The abstract says an earlier report from the same trial found body glutathione stores rose and HbA1c stabilised. No numbers in the abstract (P < 0.05 reported) Methods, limits and fundingOutcomes: Gut bacteria measured from stool by 16S sequencing Limitations: Changes in bacteria counts are not clinical outcomes; number of people not given in the abstract; the HbA1c claim comes from an earlier paper not read here. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Hauser 2009 Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord · PMID 19230029 · DOI |
Randomised controlled trial |
21 21 people with Parkinson's disease whose symptoms were not well controlled on their medicines (11 glutathione, 10 placebo; 20 analysed) |
Glutathione by intravenous infusion Intravenous 1,400 mg three times a week (amount studied, not advice) 4 weeks, then 8 weeks of follow-up · vs Placebo infusion |
No significant differences in UPDRS change. During treatment scores improved by 2.8 units more with glutathione (P = 0.32); in the next 8 weeks they worsened by 3.5 units more (P = 0.54). Glutathione was well tolerated and adverse events were similar in both groups. The authors say a mild symptom effect is possible but needs a larger study. UPDRS +2.8 units better during treatment; 3.5 worse after (P = 0.32 and P = 0.54) Methods, limits and fundingOutcomes: Unified Parkinson's Disease Rating Scale (UPDRS) scores; safety Limitations: Very small pilot, 4 weeks. Done in a supervised clinical trial with a medical-grade product, which is different from cosmetic drips. Funding and conflicts: Research support is listed as non-US government; Not stated in the abstract. Read: abstract |
| Honda 2017 Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study. BMC Gastroenterol · PMID 28789631 · DOI |
Single arm pilot trial |
34 34 adults with fatty liver disease (nonalcoholic fatty liver disease); 29 finished |
Glutathione by mouth after a 3-month lifestyle programme Oral supplement 300 mg a day (amount studied, not advice) 4 months |
ALT fell significantly after 4 months of glutathione. Triglycerides, free fatty acids and ferritin also fell. The liver-fat measure fell only in people whose ALT dropped by more than about 12.9 percent. Responders were younger and had less severe diabetes. No numbers in the abstract (Not reported in the abstract) Methods, limits and fundingOutcomes: ALT (a liver enzyme); triglycerides; ferritin; liver fat and stiffness by elastography Limitations: No placebo group, so the drop may be due to the lifestyle programme, time or chance. 5 people dropped out. Registered as UMIN000011118. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Jung 2026 Formulation-dependent differences in systemic glutathione availability: Comparative pharmacokinetics of orally dissolving film and tablet formulations in healthy adults. Eur J Pharm Biopharm · PMID 42392376 · DOI |
Randomised crossover trial |
Healthy adults (number not stated in the abstract) | Glutathione as an orally dissolving film or as a tablet Orally dissolving film vs tablet Single dose of 300 mg; then 100 mg a day for 4 weeks (amounts studied, not advice) Single dose, then 4 weeks · vs Tablet versus film |
Plasma glutathione was higher with the film at 4 and 6 hours, with a trend toward more total exposure. After 4 weeks both forms raised circulating glutathione, with no significant change in oxidative-stress markers. No adverse events were reported. No numbers in the abstract (Not reported in the abstract) Methods, limits and fundingOutcomes: Plasma glutathione over 6 hours; oxidative-stress markers after 4 weeks; adverse events Limitations: Small, short; open-label for the first study; blood levels only. Registered as KCT0011710. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Limbrunner 2025 The influence of antioxidant supplementation on adverse effects and tumor interaction during radiotherapy: a systematic review. Clin Exp Med · PMID 40691411 · DOI |
Systematic review |
People having radiotherapy for cancer, in studies of antioxidant supplements (searched April 2024) | Antioxidants including vitamins C and E, curcumin, EGCG and glutathione Various · vs Various |
Some antioxidants reduced radiation side effects. Glutathione-enhanced treatment improved compliance (people kept to treatment) but did not give significant protection against side effects. Several studies suggested that antioxidants taken during cancer treatment may weaken tumour control, increase recurrence and reduce survival. The authors say clinical recommendations are premature. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Radiation side effects; tumour control; survival; quality of life Limitations: Inconsistent evidence; glutathione is one of many antioxidants covered; the abstract does not say how many glutathione studies there were. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Mawu 2025 Effectiveness of oral glutathione in reducing nitric oxide and IL-1α concentrations for clinical improvement in mild to moderate acne vulgaris: a randomized controlled trial. Acta Dermatovenerol Alp Pannonica Adriat · PMID 41014073 |
Randomised controlled trial |
40 40 people with mild to moderate acne (22 glutathione, 18 placebo) |
Glutathione by mouth Oral supplement 500 mg once a day (amount studied, not advice) 4 weeks · vs Placebo |
Nitric oxide and IL-1 alpha were lower in the glutathione group but the changes were not statistically significant. Seven people (31.8 percent) in the glutathione group moved from moderate to mild acne. No adverse reactions were reported. The authors call it a non-significant trend. 7 of 22 (31.8 percent) improved a grade; marker changes not significant (P > 0.05) Methods, limits and fundingOutcomes: Blood nitric oxide and IL-1 alpha; acne severity (Lehmann criteria) Limitations: Small and short; the abstract gives no figure for the placebo group's acne change; needs repeating. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Mohammed 2026 The role of N-acetylcysteine and glutathione in the management of Parkinson's disease: a systematic review of oxidative biomarkers and clinical outcomes. Amino Acids · PMID 41874704 · DOI |
Systematic review |
196 9 studies, 196 people with Parkinson's disease (studies from 2009 to 2019) |
N-acetylcysteine (NAC) and glutathione (GSH), mostly by non-oral routes for glutathione Intranasal and other routes · vs Placebo or healthy controls |
NAC improved symptoms and some markers in the included studies. Intranasal glutathione gave only modest rises in brain levels with no significant symptom or oxidative-stress improvement. The authors call findings for glutathione inconclusive and evidence for both preliminary. No numbers in the abstract (Not reported in the abstract) Methods, limits and fundingOutcomes: Movement and non-movement symptoms (UPDRS), brain and blood glutathione, DaTscan Limitations: Small studies, short duration, differing routes and amounts; mostly not oral glutathione. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Richie JP Jr 2015 Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr · PMID 24791752 · DOI |
Randomised controlled trial |
54 54 healthy non-smoking adults |
Reduced glutathione by mouth Oral supplement (form not detailed in the abstract) 250 or 1,000 mg a day (amounts studied, not advice) 6 months, then 1-month washout · vs Placebo |
Blood glutathione rose at 1, 3 and 6 months versus the start at both amounts. At 6 months the high amount raised levels about 30 to 35 percent in red blood cells, plasma and lymphocytes and 260 percent in cheek cells. Levels went back to baseline after the washout. The oxidised-to-reduced ratio in whole blood fell. Natural killer cell cytotoxicity more than doubled versus placebo in the high-amount group at 3 months. Red cell, plasma and lymphocyte glutathione up 30 to 35 percent (high amount); cheek cells up 260 percent; low amount up 17 percent (blood) and 29 percent (red cells) (P < 0.05 reported; no intervals in the abstract) Methods, limits and fundingOutcomes: Glutathione in blood, red blood cells, plasma, lymphocytes and cheek cells; oxidised-to-reduced ratio; immune markers in a subset Limitations: Lab markers only; no illness or symptom outcomes. Immune markers were measured in a subset only. Healthy adults. Funding and conflicts: Research support is listed as non-US government; Not stated in the abstract. Read: abstract |
| Sarkar 2025 Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol · PMID 39444151 · DOI |
Systematic review |
Trials of topical, oral and intravenous glutathione for skin lightening and melasma (searched the past 10 years) | Glutathione: topical, oral and intravenous Topical, oral and IV Oral trials used 250 mg once or twice a day, or 500 mg once a day (amounts studied, not advice) · vs Placebo or other treatment |
Five randomised trials and one open-label study of oral glutathione reported a bigger drop in melanin index than placebo. Topical 2 percent plus oral was better than either alone. Only one placebo-controlled trial of IV glutathione existed (6 of 16 versus 3 of 16 improved, p 0.054). Risk of bias was low in about half the studies and high in the rest. The authors say IV glutathione is contraindicated because of lack of efficacy and side effects, and that skin-lightening effects are unsustainable. IV trial: 6/16 (37.5 percent) versus 3 (18.7 percent), p 0.054 (Not reported in the abstract) Methods, limits and fundingOutcomes: Melanin index; melasma improvement; side effects Limitations: Mixed study quality; short trials; the skin colour result is cosmetic, not a health result. Funding and conflicts: Review authors: Not stated in the abstract. Read: abstract |
| Schmitt 2015 Effects of N-acetylcysteine, oral glutathione (GSH) and a novel sublingual form of GSH on oxidative stress markers: A comparative crossover study. Redox Biol · PMID 26262996 · DOI |
Randomised crossover trial |
20 20 volunteers with metabolic syndrome |
N-acetylcysteine, ordinary oral glutathione and a novel sublingual glutathione Oral and sublingual 3 weeks per period (crossover) · vs Each treatment against the others |
Compared with ordinary oral glutathione, the sublingual form gave higher total and reduced glutathione in plasma and a higher GSH/GSSG ratio (p = 0.003). Vitamin E in plasma rose only with the sublingual form. The authors concluded the sublingual form was better for raising glutathione than oral glutathione or NAC. GSH/GSSG ratio higher with sublingual (p = 0.003); vitamin E up 0.83 umol/g (p = 0.04) (Not reported in the abstract) Methods, limits and fundingOutcomes: Plasma glutathione, GSH/GSSG ratio, vitamin E and other oxidative stress markers Limitations: 20 people, 3 weeks; blood markers only; tests one novel product, so it does not apply to other products. Funding and conflicts: Not stated in the abstract. The paper tests a novel product, so industry links are possible. Read: abstract |
| Sharma 2025 Systemic Inflammatory Response Syndrome Following High-Dose Intravenous Glutathione-Containing Revitalising Solution in a Patient on Tirzepatide: A Case Report. Cureus · PMID 40556995 · DOI |
Case report |
1 One woman who received a cosmetic IV infusion for skin lightening |
High-dose unregulated glutathione infusion (Glutax 75GX DCRP) Intravenous infusion Single infusion |
Within an hour she collapsed with shock and a temperature above 41 C. Tests showed very high white cells, high inflammation markers, acute liver injury (ALT 311 IU/L) and slow clotting. No infection was found. She recovered fully with supportive care. The authors suggest endotoxin contamination of the unregulated product, or a combined effect of very high glutathione in a person who was eating very little while on tirzepatide, but the cause was not proven. ALT 311 IU/L; CRP 160 mg/L; white cells 26 x 10^9/L; PT 26.4 s (Not applicable) Methods, limits and fundingOutcomes: Illness after the infusion Limitations: One case; cause not proven; cannot show how often this happens. Funding and conflicts: Case-report authors: Not stated in the abstract. Read: abstract |
| Solnier 2026 A Targeted Metabolomic Assessment of Oral Glutathione Bioavailability and Safety in Humans: A Randomized Crossover Clinical Trial. Antioxidants (Basel) · PMID 41897500 · DOI |
Randomised crossover trial |
14 14 healthy adults |
Standard oral glutathione, liposomal glutathione and a branded micellar glutathione (LipoMicel) Oral capsule forms Single doses of 500 mg (standard) and 300 mg (micellar); then 600 mg a day of the micellar form (amounts studied, not advice) Single-dose crossover, then 30 days single-arm · vs Standard form (crossover); none in the 30-day part |
The micellar form gave about 2.5 times the blood glutathione exposure of the standard form at the doses used. The GSH/GSSG ratio was higher with the micellar form. Over 30 days, liver and kidney blood markers (ALT, AST, ALP, creatinine) did not change significantly. iAUC 1287.5 vs 517.8 ug.mL.h (p = 0.0064); ratio higher (p = 0.001) (Not reported as intervals in the abstract) Methods, limits and fundingOutcomes: Whole-blood glutathione exposure; GSH/GSSG ratio; ALT, AST, ALP and creatinine Limitations: Only 14 people; the 30-day safety part had no comparison group; one branded product. Registered as NCT06345950. Funding and conflicts: Tests a branded product (LipoMicel); funding and any maker involvement are not stated in the abstract, so treat it as possibly industry-linked. Read: abstract |
| Søndergård 2021 The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial. Appl Physiol Nutr Metab · PMID 33740389 · DOI |
Randomised controlled trial |
20 20 obese men: 10 with type 2 diabetes, 10 without |
Reduced glutathione by mouth Oral supplement 1,000 mg a day (amount studied, not advice) 3 weeks · vs Placebo |
Whole-body insulin sensitivity rose in the glutathione group. Muscle glutathione rose about 19 percent but not significantly. Muscle mitochondrial hydrogen peroxide release and urine markers of oxidative damage did not change. The authors say glutathione did not change oxidative stress markers. Muscle glutathione about +19 percent (not significant) (Not reported in the abstract) Methods, limits and fundingOutcomes: Insulin sensitivity (clamp test); muscle glutathione; oxidative stress markers Limitations: Only 20 men, 3 weeks; the group sizes after splitting by diabetes are 5 to 10; needs repeating. Funding and conflicts: Registered as NCT02948673; Not stated in the abstract. Read: abstract |
| s-official-none Official fact sheets for glutathione (NIH Office of Dietary Supplements, NCCIH, MedlinePlus) · Source |
Reference database n/a |
Methods, limits and fundingRead: not-read | ||
| s-pubchem-gsh PubChem compound records: Glutathione (CID 124886) and Glutathione Disulfide (CID 65359) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial was read showing capsules prevent or treat disease in healthy people.
- No official intake figure or upper limit was found.
- The forms were each tested in single small studies, so no form is shown to be better for health.
- Long-term, pregnancy and breastfeeding safety were not covered.
- No source on label accuracy or contamination of oral products was read.
- Regulator statements on drips were not read directly.
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 8
Glutathione in blood and cells
Higher in trials in trials
The amount of glutathione measured in whole blood, red blood cells, plasma, white cells or cheek cells.
Low certaintyResults and what it means
Why it was measured
To see whether a glutathione supplement changes levels in the body.
Statistical vs. clinical meaning
A level can be changed. It is a lab marker, and higher levels have not been shown to bring a health benefit.
Safety implication
No adverse events were reported in the short trials read.
| Study | Result | People | Product |
|---|---|---|---|
| 14 | About 30 to 35 percent higher in red blood cells, plasma and lymphocytes and 260 percent higher in cheek cells at 6 months (high amount); back to baseline after a 1-month washout | 54 healthy adults | Oral glutathione versus placebo for 6 months |
| 10 | Both a tablet and a dissolving film raised circulating glutathione over 4 weeks | Healthy adults | Oral tablet or film |
Reduced-to-oxidised glutathione ratio (GSH/GSSG)
Improved in some trials in trials
A lab ratio of the active (reduced) form of glutathione to the used (oxidised) form. Researchers use it as a sign of oxidative stress.
Low certaintyResults and what it means
Why it was measured
A lower oxidised share is read as less oxidative stress in cells.
Statistical vs. clinical meaning
A change in a lab ratio. It is not proof of better health.
Safety implication
None reported in these trials.
| Study | Result | People | Product |
|---|---|---|---|
| 14 | The oxidised-to-reduced ratio in whole blood fell after 6 months in both amount groups | 54 healthy adults | Oral glutathione versus placebo |
| 16 | Higher GSH/GSSG ratio with a sublingual form than with oral glutathione (p = 0.003) | 20 people with metabolic syndrome | Sublingual glutathione versus oral glutathione and NAC |
| 18 | Higher GSH/GSSG ratio after a micellar form than after the standard form (p = 0.001) | 14 healthy adults | Micellar versus standard oral glutathione, single dose |
Skin melanin index
Lower in sun-exposed skin in several small trials in trials
A device reading of how much pigment (melanin) is in the skin. A lower number means lighter skin.
Low certaintyResults and what it means
Why it was measured
It is the usual way skin-lightening trials measure colour.
Statistical vs. clinical meaning
A cosmetic measurement. The effect does not last after stopping.
Safety implication
Non-serious side effects were reported; IV use carries more risk.
| Study | Result | People | Product |
|---|---|---|---|
| 5 | Lower melanin index in sun-exposed skin with oral and with 2 percent topical oxidised glutathione; no significant difference in sun-protected skin | 4 studies in healthy volunteers | Oral or topical glutathione |
| 15 | Five randomised oral trials and one open-label study reported a significant drop in melanin index versus placebo; one IV placebo-controlled trial: 6 of 16 versus 3 of 16 improved, p 0.054 | Trials of skin lightening and melasma | Oral, topical and IV glutathione |
Natural killer cell activity
Higher in one trial in trials
A lab test of how well a type of immune cell kills target cells.
Low certaintyResults and what it means
Why it was measured
A rise is read as more active immune cells.
Statistical vs. clinical meaning
A lab marker; no infection outcomes.
Safety implication
None reported.
| Study | Result | People | Product |
|---|---|---|---|
| 14 | More than doubled versus placebo in the high-amount group at 3 months (P < 0.05) | Subset of 54 healthy adults | Oral glutathione for 3 months |
ALT (liver enzyme)
Lower in a single-arm pilot in trials
Alanine aminotransferase, a blood test that rises when liver cells are stressed.
Very low certaintyResults and what it means
Why it was measured
Used to follow fatty liver disease.
Statistical vs. clinical meaning
Cannot be credited to glutathione without a placebo group.
Safety implication
ALT did not rise in this pilot or in a 30-day trial of 14 healthy adults.
| Study | Result | People | Product |
|---|---|---|---|
| 9 | ALT fell significantly after 4 months; no placebo group | 29 adults with fatty liver disease who finished | Oral glutathione after a 3-month lifestyle programme |
Insulin sensitivity (clamp test)
Higher in one small trial in trials
How well the body responds to insulin, measured by the hyperinsulinaemic-euglycaemic clamp.
Very low certaintyResults and what it means
Why it was measured
Poor insulin sensitivity underlies type 2 diabetes.
Statistical vs. clinical meaning
One 3-week trial in 20 men.
Safety implication
None reported.
| Study | Result | People | Product |
|---|---|---|---|
| 19 | Whole-body insulin sensitivity increased significantly with glutathione | 20 obese men, 10 with type 2 diabetes | Oral glutathione versus placebo for 3 weeks |
IL-8 and TNF-alpha (inflammation markers)
Fell in both groups, no clear difference in trials
Blood proteins that rise with inflammation.
Very low certaintyResults and what it means
Why it was measured
Used to follow inflammation in COPD.
Statistical vs. clinical meaning
No clear added effect.
Safety implication
None reported.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Both groups fell from their starting levels; the difference between groups was not significant (P > 0.05) | 50 people with COPD | Sublingual glutathione added to usual treatment versus usual treatment |
Weight-for-age z-score
No difference in trials
How a child's weight compares with other children of the same age.
Low certaintyResults and what it means
Why it was measured
Growth is a key goal in cystic fibrosis.
Statistical vs. clinical meaning
No growth benefit shown.
Safety implication
Well tolerated.
| Study | Result | People | Product |
|---|---|---|---|
| 2 | Difference -0.08 (95% CI -0.22 to 0.06; P = 0.25) between glutathione and placebo over 24 weeks | 58 children aged 2 to 10 with cystic fibrosis | Oral glutathione versus placebo |
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 4
- Glutathione drips for skin lightening are the highest-risk use. A 2025 case report describes a woman who collapsed with shock, a temperature above 41 C and acute liver injury within an hour of an unregulated cosmetic glutathione drip. She recovered fully with hospital care. A 2026 review lists liver toxicity, allergic reactions and possible kidney and hormone effects as concerns. A 2025 systematic review says IV glutathione is contraindicated because of lack of efficacy and side effects. A small supervised trial of IV glutathione in Parkinson's disease reported no safety concerns, so the risk likely depends on the product and setting, but that cannot be told from the sources. Case report and reviews 17 1 15 8
- Ask the cancer team before using any antioxidant during cancer treatment. A 2025 systematic review found glutathione-enhanced treatment did not significantly protect against radiotherapy side effects. It also reported that several studies suggest antioxidants used during cancer treatment may weaken tumour control, raise recurrence and lower survival. The authors call clinical recommendations premature. Systematic review 11
- Long-term safety of capsules is not known. The longest oral trial read lasted 6 months in 54 healthy adults. Short trials of oral forms reported no adverse events or no changes in liver and kidney blood markers. Longer use, pregnancy, breastfeeding and kidney or liver disease were not covered by the sources read. Randomised trials (short) 14 18 10
- Skin-lightening products can carry unknown ingredients. The case report authors suggest the reaction may have been caused by contamination (endotoxin) of the unregulated infusion. This was a hypothesis, not proven. Products sold for skin lightening are not all made to medical standards. Case report (hypothesis) 17
Side effects 4
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Non-serious side effects in skin-lightening studies The review does not name the effects in its abstract. A 2025 review says topical use has minimal and oral use more than minimal adverse effects, without detail. | Not given in the abstract | Non-serious Not stated | Systematic review 5 |
| Shock, fever, acute liver injury and clotting problems after a high-dose cosmetic drip The patient was also using tirzepatide and eating very little. The cause was not proven. | One reported case; no rate | Severe; hospital care; full recovery Recovered fully with supportive care | Case report 17 |
| Liver toxicity, allergic reactions, and possible kidney and hormone effects with IV glutathione These are concerns raised in a review of the literature. | No rates given | Described as concerns Not stated | Narrative review 1 |
| No adverse events in some short oral trials A 24-week trial in children with cystic fibrosis described oral glutathione as safe and well tolerated. Short trials can miss rarer problems. | None reported in the 4-week film and tablet trial or in the 4-week acne trial | Not applicable Not applicable | Randomised trials 10 12 2 |
Liver
One case of acute liver injury (ALT 311 IU/L) followed a high-dose unregulated IV product, and a 2026 review lists liver toxicity as a concern with IV use. In contrast, 30 days of a micellar oral form in 14 healthy adults did not change ALT, AST or ALP significantly. A small pilot in people with fatty liver found ALT fell, with no placebo group. No LiverTox entry was read. 17 1 18 9
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Glutathione supports liver health.
Medicines and supplements 4
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Cancer treatment, especially radiotherapy treatment | Radiotherapy works partly by making free radicals; antioxidants might also protect tumour cells (reviewers' concern). | A 2025 review reports that antioxidants during cancer treatment may reduce tumour control and survival; glutathione did not clearly protect against side effects. | Systematic review Low certainty 11 | Tell the oncology team about any supplement before starting. |
| Tirzepatide (weight-loss medicine) and low food intake prescription | Unknown. The case-report authors suggest a combined effect of very high glutathione in someone eating very little, or product contamination. | One severe reaction was reported in a person using this medicine, but a link was not shown. | Case report Very low certainty 17 | Ask a pharmacist or doctor. |
| Diabetes medicines prescription | Not studied. One 3-week trial found insulin sensitivity rose with oral glutathione. | No interaction study was found. This line exists because the trial result suggests the question is worth asking. | None found Not enough evidence 19 | Ask a pharmacist if you use glucose-lowering medicines. |
| Vitamin C given with IV glutathione supplement | Not studied. | Vitamin C is often given with IV glutathione, so the effect of glutathione alone is unclear. | Narrative review Low certainty 1 | Ask a pharmacist before combining supplements. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy and breastfeeding | No source read covered glutathione in pregnancy or breastfeeding. Ask a doctor or pharmacist. | None found |
| Children | One 24-week placebo-controlled trial gave oral glutathione to 58 children aged 2 to 10 with cystic fibrosis and described it as safe and well tolerated. This does not show safety in healthy children. | Randomised trial 2 |
| Kidney or liver disease | No source read covered this. A review lists possible kidney and liver concerns with IV use. | Narrative review 1 |
| Cancer treatment | Ask the oncology team before any antioxidant supplement. | Systematic review 11 |
| Allergy | Hypersensitivity reactions are listed as a concern with IV glutathione. No allergy data for capsules were read. | Narrative review 1 |
Overdose, product quality and regulators
Summary. No toxic amount of oral glutathione was identified in the sources read. A 2026 review raises a theoretical risk of reductive stress, which the authors present as something to study. IV products have more serious concerns.
Animal. Not reviewed.
High dose or long term signals. Not known; the longest oral trial lasted 6 months.
Overdose response. Not covered by the sources read.
Genotoxicity. Not researched.
No source read tested label accuracy or contamination of oral glutathione products.
Unregulated IV products. A case report suggests an unregulated cosmetic infusion may have been contaminated with endotoxin. This was not proven. 17
| Body | Action | Date |
|---|
When to get medical help
- Collapse, very high fever, confusion or trouble breathing within hours of a glutathione drip or injection: call emergency services.
- Rash, swelling of the face or lips, wheezing or a tight throat after any glutathione product: seek emergency care.
- Yellow skin or eyes, very dark urine or severe stomach pain after a drip or high-amount product: see a doctor today.
- If you are having cancer treatment, ask the oncology team before using any antioxidant supplement.
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 glutathione?
Does glutathione have an official recommended intake?
No official recommended intake or upper limit was found. Glutathione is made by the body and is not described as an essential nutrient in the sources read.
Do glutathione capsules raise glutathione in the body?
In one 6-month placebo-controlled trial of 54 healthy adults, blood and cell levels rose and then returned to baseline after stopping. That is a lab result, not a proven health benefit.
Does liposomal or under-the-tongue glutathione work better?
Can glutathione lighten skin?
Are glutathione drips safe?
Does glutathione help the liver?
A small pilot with no placebo group saw a liver enzyme fall in people with fatty liver. It cannot show that glutathione caused it.
Does glutathione help with diabetes or blood sugar?
Is glutathione the same as NAC?
No. NAC is a different compound that supplies cysteine, one building block of glutathione. One small crossover study compared them on blood markers only.
Is glutathione safe during cancer treatment?
Ask the cancer team first. A 2025 review found glutathione did not significantly reduce radiotherapy side effects and noted antioxidants in general may weaken tumour control.
Is glutathione safe in pregnancy or for children?
No source read covered pregnancy or breastfeeding. One trial gave oral glutathione to children with cystic fibrosis and called it well tolerated, which does not show safety in healthy children. Ask a doctor or pharmacist.
Can food give me glutathione?
No food amounts were read for this page. One abstract says the gut breaks glutathione down, so food is not a major way to raise it.
Explore by health goal
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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 started from our existing glutathione summary, looked up the chemistry in PubChem and re-read PubMed abstracts for trials, reviews and a case report. Only abstracts were read. Official NIH fact sheets were not found or were blocked, and are marked unread.
- 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. Trials of branded products may have maker links not stated in abstracts.
Sources 21
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Aloraini K, Alangari A, et al.. Glutathione for skin lightening via intravenous, oral, and topical routes: a critical narrative review of current evidence, safety, and the evidence-practice gap.. J Med Life. 2026. PMID 42751591. DOI 10.25122/jml-2026-0054. (abstract)
- Bozic M, Goss CH, et al.. Oral Glutathione and Growth in Cystic Fibrosis: A Multicenter, Randomized, Placebo-controlled, Double-blind Trial.. J Pediatr Gastroenterol Nutr. 2020. PMID 32960827. DOI 10.1097/MPG.0000000000002948. (abstract)
- Buonocore D, Grosini M, et al.. Bioavailability Study of an Innovative Orobuccal Formulation of Glutathione.. Oxid Med Cell Longev. 2016. PMID 26649136. DOI 10.1155/2016/3286365. (abstract)
- Carnib BL, Matos ERSB, et al.. Glutathione in redox homeostasis: Bridging molecular mechanisms, bioavailability constraints, and translational challenges in systemic therapeutics.. Biomed Pharmacother. 2026. PMID 42585816. DOI 10.1016/j.biopha.2026.119817. (abstract)
- Dilokthornsakul W, Dhippayom T, et al.. The clinical effect of glutathione on skin color and other related skin conditions: A systematic review.. J Cosmet Dermatol. 2019. PMID 30895708. DOI 10.1111/jocd.12910. (abstract)
- Farag A, Abass W. Evaluation of the antioxidant and anti-inflammatory effect of sublingual glutathione on COPD patients.. J Med Life. 2023. PMID 38585534. DOI 10.25122/jml-2023-0161. (abstract)
- Gaike AH, Kalamkar SD, et al.. Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals.. FEMS Microbiol Lett. 2023. PMID 37935462. DOI 10.1093/femsle/fnad116. (abstract)
- Hauser RA, Lyons KE, et al.. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease.. Mov Disord. 2009. PMID 19230029. DOI 10.1002/mds.22401. (abstract)
- Honda Y, Kessoku T, et al.. Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study.. BMC Gastroenterol. 2017. PMID 28789631. DOI 10.1186/s12876-017-0652-3. (abstract)
- Jung ES, Jang HY, et al.. Formulation-dependent differences in systemic glutathione availability: Comparative pharmacokinetics of orally dissolving film and tablet formulations in healthy adults.. Eur J Pharm Biopharm. 2026. PMID 42392376. DOI 10.1016/j.ejpb.2026.115174. (abstract)
- Limbrunner J, Doerfler J, et al.. The influence of antioxidant supplementation on adverse effects and tumor interaction during radiotherapy: a systematic review.. Clin Exp Med. 2025. PMID 40691411. DOI 10.1007/s10238-025-01804-x. (abstract)
- Mawu FO, Anwar AI, et al.. Effectiveness of oral glutathione in reducing nitric oxide and IL-1α concentrations for clinical improvement in mild to moderate acne vulgaris: a randomized controlled trial.. Acta Dermatovenerol Alp Pannonica Adriat. 2025. PMID 41014073. (abstract)
- Mohammed I, Nankya Y, et al.. The role of N-acetylcysteine and glutathione in the management of Parkinson's disease: a systematic review of oxidative biomarkers and clinical outcomes.. Amino Acids. 2026. PMID 41874704. DOI 10.1007/s00726-026-03513-5. (abstract)
- Richie JP Jr, Nichenametla S, et al.. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione.. Eur J Nutr. 2015. PMID 24791752. DOI 10.1007/s00394-014-0706-z. (abstract)
- Sarkar R, Yadav V, et al.. Glutathione as a skin-lightening agent and in melasma: a systematic review.. Int J Dermatol. 2025. PMID 39444151. DOI 10.1111/ijd.17535. (abstract)
- Schmitt B, Vicenzi M, et al.. Effects of N-acetylcysteine, oral glutathione (GSH) and a novel sublingual form of GSH on oxidative stress markers: A comparative crossover study.. Redox Biol. 2015. PMID 26262996. DOI 10.1016/j.redox.2015.07.012. (abstract)
- Sharma D, Daram S, et al.. Systemic Inflammatory Response Syndrome Following High-Dose Intravenous Glutathione-Containing Revitalising Solution in a Patient on Tirzepatide: A Case Report.. Cureus. 2025. PMID 40556995. DOI 10.7759/cureus.84736. (abstract)
- Solnier J, Du M, et al.. A Targeted Metabolomic Assessment of Oral Glutathione Bioavailability and Safety in Humans: A Randomized Crossover Clinical Trial.. Antioxidants (Basel). 2026. PMID 41897500. DOI 10.3390/antiox15030354. (abstract)
- Søndergård SD, Cintin I, et al.. The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial.. Appl Physiol Nutr Metab. 2021. PMID 33740389. DOI 10.1139/apnm-2020-1099. (abstract)
- . Official fact sheets for glutathione (NIH Office of Dietary Supplements, NCCIH, MedlinePlus). . . (not-read)
- . PubChem compound records: Glutathione (CID 124886) and Glutathione Disulfide (CID 65359). . . (full-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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