Glutathione
Glutathione is the tripeptide gamma-L-glutamyl-L-cysteinyl-glycine, the most abundant low-molecular-weight thiol in aerobic cells. It is made in the cytosol in two ATP-dependent steps by glutamate cysteine ligase and glutathione synthase, with cysteine as the rate-limiting precursor, rather than being taken up intact from the diet.
Information on this page is provided for laboratory research reference. The compound is not a drug, supplement, or medical product, and is not for human or veterinary use, ingestion, or consumption.
No reviewed report has been published for this product family yet. The molecular values opposite are public reference data, not results measured on a CRX sample.
Browse published reports →Glutathione is the central cellular reductant. Working with glutathione peroxidases it removes hydrogen peroxide, lipid hydroperoxides and peroxynitrite; with glutathione transferases it conjugates electrophiles for detoxification; and glutathione reductase regenerates it from its disulfide, GSSG. After export it is degraded extracellularly by gamma-glutamyl transferase in the gamma-glutamyl cycle, and intestinal and hepatic gamma-glutamyltransferase is why a single oral dose does not measurably raise plasma glutathione in humans. The proposed skin-lightening action, as set out in a 2016 dermatology review, is direct and indirect inhibition of tyrosinase together with a switch from eumelanin to pheomelanin synthesis. That account is not settled, and the cell work points the other way: in cultured normal human melanocytes and melanoma cells, depleting glutathione to under 10% of control with buthionine sulfoximine lowered pigment content, tyrosine hydroxylase activity and radiolabelled melanin production rather than raising them, which is the opposite direction to the marketed 'more glutathione, less pigment' story. That experiment manipulated the cysteine/glutathione balance inside cells and did not administer glutathione, so it neither supports nor refutes supplementation directly; it does mean the mechanism cannot be presented as established.1,2,3,4
Skin & hair
In a 4-week randomised, double-blind, placebo-controlled trial in 60 healthy Thai medical students, oral glutathione lowered the melanin index at all six measured sites against baseline, but the reduction beat placebo at only two of them, the right side of the face (p = 0.021) and the sun-exposed left forearm (p = 0.036).5
In a 12-week randomised, double-blind, three-arm trial in healthy Thai women, oral glutathione in reduced and oxidised forms left melanin index and UV spots only trending below placebo at all sites measured. The one outcome reaching significance versus placebo was reduced wrinkling at some sites, in the reduced-form arm only; increased skin elasticity was a non-significant trend.6
In a 10-week randomised, double-blind, matched-pair trial in 30 healthy women aged 30 to 50, an oxidised-glutathione lotion applied topically to one side of the face gave a significantly lower melanin index than the placebo lotion on the same woman's other side (P<0.001 at 10 weeks), with increased stratum corneum moisture and reduced wrinkle formation later in the study.7
A 2025 systematic review found five randomised trials and one open-arm study in which oral glutathione significantly reduced the melanin index versus placebo, but only one placebo-controlled trial of the intravenous route, in which 6/16 (37.5%) responded versus 3/16 (18.7%) on placebo, p = 0.054 and so not significant. The reviewers judged intravenous glutathione contraindicated for lack of efficacy and side effects.8
A systematic review of four clinical studies in healthy volunteers, three of them placebo-controlled, found that oral glutathione and a topical oxidised-glutathione lotion brightened sun-exposed skin by melanin index, but found no significant melanin-index reduction at sun-protected sites for any product, and rated the overall evidence inconclusive given study quality and inconsistent findings.9
Inflammation & immunity
In a 1-month pilot in 12 healthy non-smoking adults aged 50 to 80, funded by the manufacturer of the liposomal glutathione tested, oral liposomal glutathione raised whole-blood glutathione up to 40% and mononuclear-cell glutathione 100% against each participant's own baseline at 2 weeks, with natural killer cytotoxicity up to 400% higher. Participants were randomised between two oral doses; there was no placebo arm.10
In HIV-positive adults randomised to 13 weeks of oral liposomal glutathione or an empty-liposome placebo, plasma TH1 cytokines IL-1beta, IL-12, IFN-gamma and TNF-alpha rose significantly, and free radicals and the immunosuppressive cytokines IL-10 and TGF-beta fell relative to the placebo cohort. Improved control of Mycobacterium tuberculosis was demonstrated only in vitro, in blood cells drawn from those participants after supplementation.11
In a 12-month randomised, single-blind, placebo-controlled trial in 54 adult and 51 paediatric cystic fibrosis patients, inhaled glutathione missed its primary endpoint of a 15% improvement in FEV1. FEV1 rose significantly from baseline at 3, 6 and 9 months only in patients with moderate lung disease, and the 6-minute walk test improved in the paediatric group.12
Longevity & anti-ageing
In 7 healthy volunteers given a single oral dose of glutathione, plasma glutathione, cysteine and glutamate did not rise significantly above baseline over the following 270 minutes. The authors concluded systemic availability is negligible in humans because intestinal and hepatic gamma-glutamyltransferase hydrolyse the tripeptide before it reaches the circulation.4
In a 6-month randomised, double-blind, placebo-controlled trial in 54 healthy non-smoking adults, daily oral glutathione raised glutathione against participants' own baseline by 30-35% in erythrocytes, plasma and lymphocytes and 260% in buccal cells at the higher dose, and by 17-29% in blood and erythrocytes at the lower. Natural killer cytotoxicity rose over twofold versus placebo at 3 months. Levels returned to baseline after a 1-month washout.13
Focus & brain health
In a randomised, double-blind pilot in 21 people with Parkinson's disease whose motor symptoms were inadequately controlled on medication, intravenous glutathione three times weekly for 4 weeks produced no significant UPDRS change versus placebo: the ADL-plus-motor score improved 2.8 units more on glutathione (P = 0.32), then worsened 3.5 units more over the next 8 weeks (P = 0.54).14
In a 3-month double-blind phase IIb trial in 45 people with Hoehn and Yahr stage 1-3 Parkinson's disease, intranasal glutathione was not superior to saline placebo at either dose. The high-dose group improved on total UPDRS (-4.6, P = 0.0025) against its own baseline, but every cohort improved including placebo, whose improvement was larger than in previous Parkinson's trials.15
What investigators recorded alongside the results above, at the rates their papers state.
Toxic epidermal necrolysis attributed to orally taken glutathione whitening pills in a single patient, with causation supported by enzyme-linked immunospot assay and liquid chromatography-mass spectrometry.16
single published case report
A 2016 peer-reviewed dermatology review reports that adverse effects caused by intravenous glutathione led the Food and Drug Administration of the Philippines to issue a public warning condemning its use for off-label indications including skin lightening. The same review states there is no evidence proving the efficacy of intravenous glutathione injections. This is the review's account of the regulator's action, not the regulator's own notice.2
regulatory action reported second-hand in a review, incidence not quantified
No published study of long-term intravenous glutathione exists for any indication. A MEDLINE review found every included trial ran only a few intravenous doses or 4-12 weeks, and found no published study at all of intravenous glutathione used for skin lightening.17
absence of long-term safety data
Theoretical risk of increased sun-induced skin cancer, because the proposed mechanism switches pigment production from brown eumelanin to red pheomelanin in individuals whose skin was previously photoprotected. Raised by reviewers as a safety concern; not measured in any trial.17
hypothesised, not measured
Cardiomyopathy developed in one participant in the high-dose intranasal glutathione cohort of a phase IIb Parkinson's disease trial.15
1 participant, in the high-dose cohort of 45 randomised across three arms
A 2025 systematic review characterised oral glutathione's adverse effects as substantial relative to topical glutathione's minimal ones, and judged the intravenous route contraindicated on grounds of both lack of efficacy and side effects.8
review judgement, incidence not pooled
- 1.Glutathione and glutathione-dependent enzymes: From biochemistry to gerontology and successful aging. · Ageing Research Reviews · 2023 · PMID 37683986
- 2.Glutathione as a skin whitening agent: Facts, myths, evidence and controversies. · Indian Journal of Dermatology, Venereology and Leprology · 2016 · PMID 27088927
- 3.Co-regulation of melanin precursors and tyrosinase in human pigment cells: roles of cysteine and glutathione. · Cellular and Molecular Biology (Noisy-le-Grand, France) · 1999 · PMID 10644002
- 4.The systemic availability of oral glutathione. · European Journal of Clinical Pharmacology · 1992 · PMID 1362956
- 5.Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. · The Journal of Dermatological Treatment · 2012 · PMID 20524875
- 6.Glutathione and its antiaging and antimelanogenic effects. · Clinical, Cosmetic and Investigational Dermatology · 2017 · PMID 28490897
- 7.Skin-whitening and skin-condition-improving effects of topical oxidized glutathione: a double-blind and placebo-controlled clinical trial in healthy women. · Clinical, Cosmetic and Investigational Dermatology · 2014 · PMID 25378941
- 8.Glutathione as a skin-lightening agent and in melasma: a systematic review. · International Journal of Dermatology · 2025 · PMID 39444151
- 9.The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. · Journal of Cosmetic Dermatology · 2019 · PMID 30895708
- 10.Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. · European Journal of Clinical Nutrition · 2018 · PMID 28853742
- 11.Liposomal Glutathione Supplementation Restores TH1 Cytokine Response to Mycobacterium tuberculosis Infection in HIV-Infected Individuals. · Journal of Interferon & Cytokine Research · 2015 · PMID 26133750
- 12.Randomized, single blind, controlled trial of inhaled glutathione vs placebo in patients with cystic fibrosis. · Journal of Cystic Fibrosis · 2015 · PMID 25458463
- 13.Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. · European Journal of Nutrition · 2015 · PMID 24791752
- 14.Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. · Movement Disorders · 2009 · PMID 19230029
- 15.Phase IIb Study of Intranasal Glutathione in Parkinson's Disease. · Journal of Parkinson's Disease · 2017 · PMID 28436395
- 16.Glutathione Whitening Pills Induced Toxic Epidermal Necrolysis: An Unusual Case Confirmed by Enzyme-Linked Immunospot Assay and Liquid Chromatography-Mass Spectrometry. · Dermatitis · 2021 · PMID 34608063
- 17.Intravenous glutathione for skin lightening: Inadequate safety data. · South African Medical Journal · 2016 · PMID 27499402