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TripeptideLimited humanNot FDA approved

Glutathione

Glutathione (reduced glutathione)

Last reviewed October 27, 2026 · 23 sources · Written for general readers · Compare with another compound →

The bottom line

Glutathione is an antioxidant your body makes on its own from three amino acids, and the liver relies on it to neutralize some toxins. Small trials suggest pills or creams can lighten skin a little for as long as people keep taking them, but pills do not always raise body levels, inhaled and IV forms did not help lung or Parkinson's patients, and a 2025 systematic review advised against IV use for skin. FDA has warned about compounded IV glutathione made from supplement grade powder that made patients sick.

Where the evidence stands

What it is

Glutathione is a tripeptide, a very small peptide made of three amino acids, that the body makes on its own. It acts as an antioxidant, which means it helps neutralize damaging molecules inside cells.[1][2]

The body builds it from glutamate, cysteine and glycine. Levels tend to be lower in older adults, and giving older adults cysteine and glycine as building blocks raised their glutathione in a small trial.[1][3]

It is sold as pills, lozenges, creams, inhaled sprays and IV drips, and it is widely promoted for skin lightening, detox and anti aging.[2][4]

Name
Glutathione (Glutathione (reduced glutathione))
Other names
GSH, L-glutathione, glutathione IV, glutathione injections
Type
Tripeptide
CAS number
70-18-8
Formula
C10H17N3O6S
Molecular weight
About 307.3 g/mol

What it does in the body

Glutathione is a natural tripeptide that nearly every cell makes from glutamate, cysteine and glycine.[1][3] It acts as a built in antioxidant, and the liver relies on it to help neutralize some toxins; an FDA approved overdose antidote is thought to work partly by restoring it.[2][8]

This is the biology, area by area. A change measured in the body, like a higher blood level, does not always mean a person feels a benefit. The claims check below covers that.

Liver and detox

Well established

After an acetaminophen overdose, a toxic breakdown product can injure the liver. The FDA approved antidote acetylcysteine is thought to protect the liver by maintaining or restoring glutathione, or by binding the toxic product directly.[8] This is the clearest proof that the liver depends on glutathione for detox. Taking glutathione itself for everyday detox has not been tested well: a fatty liver pilot study without a comparison group found lower liver stress markers after four months of pills.[9]

Antioxidant stores

Measured in people

Whether swallowed glutathione raises body levels is debated. In a six month placebo controlled trial of 54 adults, pills raised glutathione in blood by about 17 to 35 percent and in cheek cells by up to 260 percent, and levels fell back one month after stopping.[6] But in a four week placebo controlled trial of 40 adults, pills did not change glutathione in red blood cells or markers of oxidative stress.[10] In 12 adults given a liposomal form for one month without a placebo group, whole blood glutathione rose up to 40 percent.[11]

Skin and pigment

Measured in people

Glutathione is thought to shift pigment cells from dark brown melanin toward a lighter, reddish type.[2][5] In trials, pills lowered measured melanin modestly versus placebo, and the effect faded after stopping.[4][12] Some experts worry the reddish type of melanin could offer less sun protection, but this has not been proven.[5]

Immune system

Measured in people

In the six month pill trial, natural killer cell activity, part of the immune defense against viruses and tumors, more than doubled at three months in one group.[6] In the small liposomal study, natural killer activity rose up to fourfold within two weeks, but there was no placebo group.[11] No trial has shown fewer infections or illnesses.

Lungs

Measured in people

In 153 people with cystic fibrosis who inhaled glutathione or placebo for six months, glutathione levels rose in their mucus, showing it reached the lungs. But lung function did not improve, and markers of oxidative stress and inflammation did not fall.[13]

Aging and mitochondria

Measured in people

In a 16 week placebo controlled trial, 24 older adults took glycine and N acetylcysteine (a cysteine source), the building blocks of glutathione. Their glutathione deficiency was corrected, and mitochondrial fat burning, inflammation, insulin resistance, strength and walking speed improved.[3] This tested building blocks, not glutathione itself, and the trial was small.

Brain and nerves

Measured in people

In Parkinson's disease, four weeks of IV glutathione in 21 patients and three months of a nasal spray in 45 patients did not improve symptoms more than placebo.[14][15]

How it works

The proposed idea for skin is that glutathione changes how pigment is made.

  • Glutathione is thought to affect melanogenesis, the process skin cells use to make pigment.[2]
  • Some experts worry the shift toward a reddish type of melanin could raise sun related skin cancer risk, though this has not been proven.[5]
  • Swallowed glutathione can raise the body’s own glutathione stores over months, which suggests some of it is absorbed or helps the body make more.[6]
  • When IV glutathione is given with vitamin C, as is common, it is hard to tell which ingredient did what.[7]

The skin and detox ideas are mostly theory. Studies have not shown how much IV glutathione changes skin over time.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

Lab and theory, not the focus

  • Lab studies suggest glutathione affects melanogenesis, the way pigment cells make melanin.[2]
  • Glutathione is believed to push pigment cells from dark brown melanin toward a lighter, reddish type, which is the basis for theoretical worries about sun damage.[5]
  • Reviews describe lab and early research on how glutathione affects pigment, but the debate centers on human cosmetic use.[7]

Limit: Lab findings on pigment cells do not tell us what a pill or drip does to the whole body.

Human studies

Small, short trials; pills help a little, IV not supported

  • Pills for skin: 60 healthy medical students in Thailand took glutathione capsules or placebo for four weeks. Melanin fell at all six sites measured, and the drop beat placebo at two. Both groups tolerated treatment very well.[12]
  • Pills for skin aging: healthy women took glutathione pills, a related form called oxidized glutathione, or placebo for 12 weeks. Wrinkles fell with glutathione, melanin and dark spots tended to be lower, and no serious side effects occurred.[18]
  • Cream and pills: 46 people used glutathione cream and pills, or placebo, for eight weeks. The combination lightened skin more than placebo.[16]
  • IV for skin: in the only placebo controlled IV trial, 6 of 16 responded on glutathione versus 3 of 16 on placebo, which was not significant.[4]
  • Body stores: 54 adults took glutathione pills or placebo for six months. Glutathione in blood and cheek cells rose and immune cell activity increased, then fell back after stopping.[6]
  • Body stores, short term: 40 healthy adults took glutathione pills or placebo for four weeks. Glutathione in red blood cells and markers of oxidative damage did not change.[10]
  • Liposomal form: 12 healthy adults took a liposomal glutathione for one month, without a placebo group. Whole blood glutathione rose up to 40 percent and immune cell activity rose by two weeks.[11]
  • Fatty liver: in an uncontrolled pilot study, 29 people who finished four months of glutathione pills had lower ALT, a liver stress marker.[9]
  • Parkinson’s disease: four weeks of IV glutathione in 21 patients showed no significant benefit over placebo and was well tolerated.[14] A three month nasal spray trial in 45 patients also found no benefit over placebo.[15]
  • Cystic fibrosis: 153 patients inhaled glutathione or placebo for six months. Glutathione reached the lungs, but lung function did not improve versus placebo, and side effects were similar in both groups.[13]
  • Building blocks in older adults: 24 older adults took glycine and N acetylcysteine or placebo for 16 weeks. Glutathione deficiency, mitochondrial function, inflammation and walking speed improved, and the mix was well tolerated. This did not test glutathione itself.[3]
  • Reviews: a 2026 review called the skin studies small, short and inconsistent, and said they do not support routine cosmetic use.[7]

Limit: Studies are small and brief, skin effects fade after stopping, and none show IV glutathione is safe over the long term.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Lightens skin

Mixed results

Pills: in a four week trial of 60 Thai medical students, glutathione capsules lowered skin melanin at all six sites tested, but the drop beat placebo at only two (one side of the face and a sun exposed forearm).[12] A 2025 systematic review found five randomized trials of pills that lowered melanin versus placebo, with moderate effects that did not last after stopping.[4] Creams plus pills: in 46 people over eight weeks, the combination lightened skin more than placebo.[16] An earlier review of three trials found one showed no benefit and two helped only some body sites or age groups.[17]

IV drips give lighter, brighter skin

No benefit in trials so far

Only one placebo controlled IV trial exists. About 6 of 16 people responded on glutathione versus 3 of 16 on placebo, a difference that was not statistically significant.[4] The 2025 review said IV glutathione should not be used, given the lack of benefit and its side effects.[4] No study has looked at long term IV safety.[5]

Reduces wrinkles and skin aging

Mixed results

In a 12 week placebo controlled trial in healthy women, glutathione pills reduced wrinkles compared with placebo, and skin elasticity tended to improve.[18] This is a single small trial that has not been repeated.

Detoxes and protects the liver

Mixed results

In a pilot study of people with fatty liver disease, 29 finished four months of glutathione pills after a period of diet and exercise. A liver enzyme called ALT, a marker of liver stress, went down, as did blood fats. There was no comparison group, so the change cannot be credited to glutathione.[9] The liver does use glutathione to neutralize toxins, which is how the FDA approved acetaminophen overdose antidote is thought to work, but that drug is acetylcysteine, not glutathione.[8]

Boosts antioxidants and immunity

Mixed results

In a six month placebo controlled trial of 54 adults, glutathione pills raised glutathione in blood by about 17 to 35 percent and in cheek cells by up to 260 percent, and natural killer cell activity, part of the immune system, more than doubled at three months in one group. Levels went back to baseline one month after stopping.[6] A four week placebo controlled trial of 40 adults found no change in glutathione levels or oxidative stress markers.[10] These are lab markers, and no trial has shown fewer infections or illnesses.

Helps Parkinson’s disease and brain health

No benefit in trials so far

In 21 people with Parkinson’s disease, four weeks of IV glutathione did not improve symptom scores significantly more than placebo.[14] In 45 people over three months, a glutathione nasal spray was not better than a saltwater placebo, although all groups, including placebo, improved.[15]

Helps lung conditions when inhaled

No benefit in trials so far

In a six month placebo controlled trial of 153 people with cystic fibrosis aged 8 and up, inhaled glutathione reached the lungs but did not improve lung function, the main goal. A small gain seen at three months did not last, and inflammation markers did not fall.[13]

Slows aging and boosts energy

Not tested

No trial has given glutathione itself to test aging or energy. One small 16 week trial gave 24 older adults glycine and N acetylcysteine, glutathione's building blocks, and found better glutathione levels, mitochondrial function and strength than placebo.[3] Skin aging was tested separately in one small pill trial.[18]

Known risks and side effects

  • Contaminated compounded IV doses. In 2019 seven patients had nausea, vomiting and chills within minutes of compounded IV glutathione, and one was hospitalized. FDA found high levels of bacterial toxins in the powder used.[19] In 2024 FDA again warned compounders that food grade ingredients are not suitable for sterile injections.[20]
  • Side effects seen in trials. Pills were well tolerated in short trials, with no serious side effects reported.[12][18] In the nasal spray trial, one person on glutathione developed a heart muscle problem; the report does not say it was caused by the spray.[15]
  • Organ and allergy concerns with IV use. Reviews of IV use raise concerns about liver injury, allergic reactions and possible kidney and hormone effects, and no study has looked at repeated IV use over the long term.[7][5]
  • Unregulated products. Glutathione for injection is not FDA approved and is still under FDA review for compounding.[21] The 2019 problem came from powder meant only for supplements,[19] and products bought online for self injection carry the same risk.
  • Sport rules on IV drips. For athletes, WADA bans IV infusions over 100 mL in 12 hours outside hospital care.[22] The 2027 list, in force January 1, 2027, keeps the same rule.[23]

Regulatory status

Today: Glutathione is not an FDA approved injectable drug. FDA lists it in Category 1, meaning it is still under evaluation for use by compounding pharmacies.[21]

  1. FDA warns compounders after patients react to IV glutathione made from supplement grade powder.[19]
  2. FDA issues a compounding alert on using the dietary ingredient glutathione to make sterile injections.[19]
  3. FDA reminds compounders that food grade ingredients are not suitable for sterile injections and points back to its earlier glutathione warning.[20]
  4. FDA’s updated list keeps glutathione under evaluation for compounding.[21]

Sources

  1. U.S. FDA Global Substance Registration System. Glutathione (UNII GAN16C9B8O). FDA GSRS
  2. Alzahrani TF, Alotaibi SM, Alzahrani AA, et al. Exploring the Safety and Efficacy of Glutathione Supplementation for Skin Lightening: A Narrative Review. Cureus. 2025;17(1):e78045. PMID 40013212
  3. Kumar P, Liu C, Suliburk J, 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. DOI 10.1093/gerona/glac135
  4. Sarkar R, Yadav V, Yadav T, et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol. 2025;64(6):992-1004. PMID 39444151
  5. Davids LM, Van Wyk JC, Khumalo NP. Intravenous glutathione for skin lightening: Inadequate safety data. S Afr Med J. 2016;106(8):782-6. PMID 27499402
  6. Richie JP Jr, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015;54(2):251-263. PMID 24791752
  7. Alkhodairy F, Aloraini K, Alangari A, Arif JM. 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
  8. ACETADOTE (acetylcysteine) injection. Prescribing information. DailyMed, U.S. National Library of Medicine. Revised July 2025. DailyMed
  9. Honda Y, Kessoku T, Sumida Y, et al. Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study. BMC Gastroenterol. 2017;17(1):96. PMID 28789631
  10. Allen J, Bradley RD. Effects of Oral Glutathione Supplementation on Systemic Oxidative Stress Biomarkers in Human Volunteers. J Altern Complement Med. 2011;17:827-833. PMID 21875351
  11. Sinha R, Sinha I, Calcagnotto A, 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
  12. Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. J Dermatolog Treat. 2012;23(2):97-102. PMID 20524875
  13. Griese M, Kappler M, Eismann C, et al. Inhalation treatment with glutathione in patients with cystic fibrosis. A randomized clinical trial. Am J Respir Crit Care Med. 2013;188(1):83-89. PMID 23631796
  14. Hauser RA, Lyons KE, McClain T, et al. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord. 2009;24(7):979-983. PMID 19230029
  15. Mischley LK, Lau RC, Shankland EG, et al. Phase IIb Study of Intranasal Glutathione in Parkinson's Disease. J Parkinsons Dis. 2017;7(2):289-299. PMID 28436395
  16. Wahab S, Anwar AI, Zainuddin AN, 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
  17. Sitohang IBS, Ninditya S. Systemic Glutathione as a Skin-Whitening Agent in Adult. Dermatol Res Pract. 2020;2020:8547960. PMID 32373172
  18. Weschawalit S, Thongthip S, Phutrakool P, et al. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol. 2017;10:147-153. PMID 28490897
  19. U.S. Food and Drug Administration. FDA highlights concerns with using dietary ingredient glutathione to compound sterile injectables. Compounding alert, June 7, 2019. FDA
  20. U.S. Food and Drug Administration. FDA reminds compounders to use ingredients suitable for sterile compounding. Compounding alert, October 30, 2024. FDA
  21. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act. Updated May 14, 2026. FDA
  22. World Anti-Doping Agency. The Prohibited List (2026 List, in force from January 1, 2026). WADA
  23. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2027. Published September 2026, in force January 1, 2027. WADA 2027 Prohibited List
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

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