Glutathione
A tripeptide every cell makes, sold as a pill, a drip and a skin lightener; oral doses raised body stores in a six-month trial, while the IV drip's evidence is thin
Glutathione is a three-amino-acid peptide (glutamate, cysteine, glycine) that cells use to neutralise reactive oxygen species. Oral supplements were long assumed to be digested, but a 2015 randomised trial found they raised body stores over six months. Its use as an intravenous skin lightener rests on very little controlled evidence.
What is it?
Glutathione is the most abundant small antioxidant inside cells. Its cysteine carries the thiol group that donates electrons to neutralise reactive molecules, after which two glutathione molecules pair up as the oxidised form; the ratio of reduced to oxidised glutathione is a standard measure of oxidative stress.
Because the body makes its own, the question for supplements is whether taking more changes anything. The trials below show oral glutathione can raise levels in blood cells over weeks to months and shift oxidative-stress markers. Whether that improves health outcomes has not been shown in a trial designed to test it.
Intravenous glutathione has its most interesting result in the heart. In 100 patients having primary angioplasty for a heart attack, four infusions over three days blunted inflammation and troponin release against placebo, and a later subanalysis found shorter hospital stays. That is one trial, and its stay finding was not the primary outcome.
Elsewhere the trials are small and mostly negative or mixed. Added to ketamine for depression, it did nothing extra; in autistic children it did not change behaviour; in acne the changes were not significant. With entecavir in chronic hepatitis B, liver measures improved more than with entecavir alone. An alternative is to supply its building blocks: glycine plus N-acetylcysteine restored glutathione and improved several ageing markers in older adults.
Its most visible use is cosmetic: oral, topical and intravenous glutathione sold to lighten skin. Small randomised trials report modest changes in melanin with oral and topical forms; a 2026 review judged intravenous use unsupported and flagged liver, allergic, kidney and hormonal safety concerns.
Mechanism of Action
Glutathione is a cysteine-containing tripeptide, the most abundant small antioxidant inside cells; the ratio of its reduced to oxidised forms is a standard marker of oxidative stress.
Antioxidant
Its thiol donates electrons to neutralise reactive molecules, and two oxidised molecules pair up afterwards.
Inflammation after reperfusion
Infused around angioplasty, it lowered NOX2 activation, inflammatory markers and troponin release.
Building blocks
Supplying glycine and N-acetylcysteine, its precursors, restored glutathione levels in older adults.
Published Research
Human trials and two reviews naming glutathione, read from their PubMed abstracts on October 4, 2026.
Six months of oral glutathione
54 healthy non-smoking adults were randomised, double-blind, to 250 or 1,000 mg/day or placebo for six months. At the high dose, glutathione rose 30-35% in red cells, plasma and lymphocytes and 260% in cheek cells; levels returned to baseline after a one-month washout, and oxidised-glutathione ratios fell in both dose groups.
Liposomal glutathione pilot
In 12 healthy adults taking 500 or 1,000 mg/day of liposomal glutathione for a month, blood levels rose within a week, peaking after two weeks (up to 40% in whole blood), with lower 8-isoprostane and higher natural-killer cell activity. A small pilot without a placebo group.
Diabetes and the gut microbiome
In Indian adults with type 2 diabetes randomised to 500 mg/day for six months alongside their diabetes treatment, the authors' earlier report showed higher glutathione stores and stabilised HbA1c; here, stool sequencing showed fewer Proteobacteria and less Escherichia/Shigella in the supplemented group.
Oral plus topical for skin
46 participants received oral glutathione or placebo and applied glutathione cream to one side of the face and placebo to the other for 8 weeks. The combination gave the lowest melanin index and was significantly better than placebo; both forms were effective alone, the combination more so.
Infusion around primary angioplasty
In 100 STEMI patients, glutathione 2,500 mg infused over 10 minutes before PCI and at 24, 48 and 72 hours lowered inflammatory markers, NOX2 activation and troponin release against placebo, and a smaller inflammatory response tracked better heart function at follow-up.
Shorter hospital stays after STEMI
In a subanalysis of that trial, patients given glutathione stayed 8.6 days against 10.8 on placebo; length of stay was not the trial's primary outcome.
Film versus tablet
An orally dissolving film gave higher plasma glutathione at 4 and 6 hours than a tablet; over 4 weeks both raised circulating glutathione without changing oxidative-stress markers.
Chronic hepatitis B
In 90 patients with chronic hepatitis B on entecavir, adding reduced glutathione for 3 months gave larger improvements in liver enzymes, bilirubin, albumin and fibrosis markers than entecavir alone.
Added to ketamine for depression
In a double-blind trial of 30 people with major depression, adding intravenous glutathione to ketamine infusions did not improve depression scores over ketamine with saline.
Autistic children
In a double-blind crossover pilot, glutathione alone or with vitamin C and N-acetylcysteine did not improve behaviour or biological measures in autistic children with disruptive behaviour.
Acne
In a randomised trial in mild to moderate acne, oral glutathione for 4 weeks produced non-significant falls in nitric oxide and IL-1α, with 7 of 22 patients improving to mild.
GlyNAC in older adults
In older adults with glutathione deficiency, 16 weeks of glycine plus N-acetylcysteine, its building blocks, corrected glutathione levels and improved oxidative stress, mitochondrial markers and physical function against placebo.
Type 1 diabetes in adolescents
Better glucose control over 3 months, with or without dietary antioxidants, did not change blood glutathione or oxidation markers in adolescents with type 1 diabetes.
Skin lightening and melasma
Five randomised trials of oral glutathione, at 250 mg once or twice a day or 500 mg once a day, reduced the melanin index compared with placebo; topical 0.5% outperformed 0.1%; only one placebo-controlled trial of intravenous glutathione was found.
The case against the IV drip
A critical review of intravenous glutathione for skin lightening found modest, variable pigment changes in small, short studies, with vitamin C usually given alongside, and raised concerns about liver toxicity, hypersensitivity and possible kidney and hormonal effects; it judged routine cosmetic use unjustified.
Brain glutathione in depression
Across 8 magnetic resonance spectroscopy studies, glutathione was lower in the occipital cortex of people with depression but not in the medial frontal cortex.
Dosing Data
Glutathione is not an FDA-approved drug. Oral products are supplements; trial doses below include an intravenous regimen from a heart-attack study.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Side Effects & Contraindications
Reported Side Effects
From the trials and reviews above.
Contraindications & Cautions
Not a regulated drug in the US, so no label lists them.
Legal Status
Sold as a dietary supplement and cosmetic ingredient; not an approved drug.
Frequently Asked Questions
?Does oral glutathione get absorbed?
A six-month randomised trial found 1,000 mg/day raised glutathione in red cells, plasma and lymphocytes by 30-35%, so some does reach the body.
?Does glutathione lighten skin?
Small randomised trials report modest drops in melanin with oral and topical forms; intravenous use has very little controlled evidence and raises safety concerns.
?Is IV glutathione safe?
Not established. A 2026 review flagged liver, allergic, kidney and hormonal concerns and judged cosmetic use unjustified.
?Is glutathione a peptide?
Yes: a tripeptide of glutamate, cysteine and glycine, with an unusual gamma bond.
?Does IV glutathione help after a heart attack?
One 100-patient trial found infusions around primary angioplasty reduced inflammation and troponin release, and a subanalysis found shorter hospital stays. No larger confirmatory trial appeared in the sources read.
?Are there better ways to raise glutathione?
In older adults with low levels, 16 weeks of glycine plus N-acetylcysteine, its building blocks, restored glutathione in a placebo-controlled trial.
References
- [pubmed] Richie JP Jr, et al. "Randomized controlled trial of oral glutathione supplementation on body stores of glutathione." Eur J Nutr, 2015;54(2):251-63. PMID: 24791752.
- [pubmed] Sinha R, et al. "Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function." Eur J Clin Nutr, 2018;72(1):105-111. PMID: 28853742.
- [pubmed] Gaike AH, et al. "Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals." FEMS Microbiol Lett, 2023;370. PMID: 37935462.
- [pubmed] Wahab S, et al. "Combination of topical and oral glutathione as a skin-whitening agent: a double-blind randomized controlled clinical trial." Int J Dermatol, 2021;60(8):1013-1018. PMID: 33871071.
- [pubmed] Sarkar R, et al. "Glutathione as a skin-lightening agent and in melasma: a systematic review." Int J Dermatol, 2025;64(6):992-1004. PMID: 39444151.
- [pubmed] Aloraini K, 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;19(7):511-523. PMID: 42751591.
- [pubmed] Santacroce G, et al. "Glutathione: Pharmacological aspects and implications for clinical use in non-alcoholic fatty liver disease." Front Med (Lausanne), 2023;10:1124275. PMID: 37035339.
- [pubmed] Tanzilli G, et al. "Glutathione Infusion Before and 3 Days After Primary Angioplasty Blunts Ongoing NOX2-Mediated Inflammatory Response." J Am Heart Assoc, 2021;10(18):e020560. PMID: 34533039.
- [pubmed] Arrivi A, et al. "Early and prolonged glutathione infusion favorably impacts length of hospital stay in ST-elevation myocardial infarction patients: a subanalysis of the GSH2014 Trial." Minerva Cardiol Angiol, 2023;71(2):147-152. PMID: 36083043.
- [pubmed] Jung ES, 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;226:115174. PMID: 42392376.
- [pubmed] Wei Q, et al. "Therapeutic effects of reduced glutathione on liver function, fibrosis, and HBV DNA clearance in chronic hepatitis B patients." BMC Gastroenterol, 2025;25(1):68. PMID: 39920583.
- [pubmed] Eshkevari L, et al. "Efficacy of addition of the anti-inflammatory, IV glutathione to standard ketamine IV therapy in major depressive disorder." Psychiatry Res, 2024;337:115949. PMID: 38795698.
- [pubmed] Williams PG, et al. "Glutathione, Vitamin C, and Cysteine Use in Autistic Children With Disruptive Behavior: A Double-Blind, Placebo-Controlled Crossover Pilot Study." J Dev Behav Pediatr, 2025;46(1):e17-e24. PMID: 39960783.
- [pubmed] Mawu FO, 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;34(3):95-99. PMID: 41014073.
- [pubmed] Kumar P, et al. "Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial." J Gerontol A Biol Sci Med Sci, 2023;78(1):75-89. PMID: 35975308.
- [pubmed] Benson M, et al. "Improved glycemic control either alone, or combined with antioxidant supplementation, fails to restore blood glutathione or markers of oxidative stress in adolescents with poorly controlled type 1 diabetes." Nutr Res, 2023;117:83-90. PMID: 37515943.
- [pubmed] Bell CJM, et al. "Glutathione alterations in depression: a meta-analysis and systematic review of proton magnetic resonance spectroscopy studies." Psychopharmacology (Berl), 2025;242(4):717-724. PMID: 39708105.
Sources & Citations
Studies were read from their PubMed abstracts. Read October 7, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.