Glutathione lightened the skin in several placebo-controlled clinical trials. At 500 mg a day for four weeks, the melanin index fell significantly on the face and on the sun-exposed forearm. In another trial, glutathione in a cream combined with capsules gave lighter skin than either form alone. Below you will find how glutathione affects skin pigment, what each trial measured and which forms have the best data.
What is glutathione?
Glutathione is a tripeptide, a short chain of three amino acids: glutamic acid, cysteine and glycine. The body makes it itself, and inside cells it occurs mainly in its reduced form, abbreviated GSH. Glutathione is one of the most important antioxidants inside the cell. It keeps the balance between oxidation and reduction, which means it neutralises reactive oxygen species.
Besides the reduced form there is an oxidised form, written GSSG. It forms when two glutathione molecules give up electrons to neutralise free radicals. Both forms have been studied as agents that improve the look of the skin. The wider background, including the role of glutathione as an antioxidant, is covered in the guide on NAD and glutathione injections.
How does glutathione affect skin colour?
Glutathione inhibits tyrosinase, the enzyme that starts pigment production in the skin. A 2016 review in the Indian Journal of Dermatology, Venereology and Leprology describes two routes for this effect. The first is direct and indirect inhibition of tyrosinase. The second is switching melanocytes from making dark eumelanin to the lighter pheomelanin.
Melanocytes produce both pigments side by side, and skin colour depends on the ratio between them. More eumelanin gives a brown tone, more pheomelanin a lighter, yellowish-pink one. Glutathione shifts this ratio towards the lighter side.
What did trials of glutathione capsules show?
Glutathione taken by mouth lowered the skin melanin index in several placebo-controlled trials. The melanin index is a number from a device that measures how much light the pigment in the skin absorbs. The lower the result, the lighter the skin. The table collects the three most often cited papers.
| Trial | Who took part | What was taken | Result |
|---|---|---|---|
| Arjinpathana and Asawanonda, 2012 | 60 medical students | 500 mg GSH a day for 4 weeks | melanin index fell at all 6 sites, significantly on the face and sun-exposed forearm |
| Weschawalit et al., 2017 | healthy women | 250 mg GSH or 250 mg GSSG a day for 12 weeks | trend towards a lower melanin index and fewer UV spots, fewer wrinkles at some sites with GSH |
| Wahab et al., 2021 | 46 people | glutathione in capsules and in cream, 8 weeks | the combination of both forms gave the lightest skin of all groups |
The first of these trials was run at a university hospital in Bangkok. Participants received 500 mg of glutathione in two portions, or placebo. After four weeks the melanin index had dropped at all six measured sites. The difference from placebo was significant on the right side of the face and on the sun-exposed forearm. The number of UV spots, counted with a VISIA device, fell in a similar way.
Does glutathione also work on wrinkles and elasticity?
In a 2017 trial, glutathione reduced the number of wrinkles at some of the measured sites. The paper was published in Clinical, Cosmetic and Investigational Dermatology. For 12 weeks women took 250 mg of the reduced form, 250 mg of the oxidised form or placebo. In the reduced-form group there were significantly fewer wrinkles at some sites than in the placebo group.
Both forms of glutathione also showed a trend towards better skin elasticity. The melanin index and the number of UV spots showed a trend towards lower values than on placebo, both on the face and on the arm. The authors stressed that doses lower than the previously studied 500 mg proved effective. There were no serious side effects in the whole trial.
Does glutathione cream lighten the skin?
Yes, glutathione applied to the skin also lowered the melanin index. A 2025 systematic review in the International Journal of Dermatology gathered trials from the past ten years. A cream with 0.5 percent glutathione worked significantly better than a 0.1 percent cream and better than placebo. Combining a 2 percent glutathione cream with capsules proved more effective than either form alone.
The same review counted five randomised trials and one open-label trial of oral glutathione. Doses were 250 mg once a day, 250 mg twice a day or 500 mg once a day. All of these papers showed a significant drop in the melanin index compared with placebo. The effect of a cream is local, while the effect of capsules covers the whole body.
On which parts of the body was the effect largest?
The clearest lightening was measured on sun-exposed sites such as the face and forearm. A 2019 systematic review in the Journal of Cosmetic Dermatology gathered four trials in healthy volunteers. Both 500 mg of oral glutathione and a cream with 2 percent of the oxidised form lightened the skin on sun-exposed sites.
On sun-protected sites, such as the inner side of the arm, no differences were found with either form. The result suggests that glutathione acts mainly where skin darkens from the sun. The natural skin colour on protected sites stayed the same.
What is known about glutathione given by injection?
Injected glutathione has far less data than capsules and cream. The 2025 review found only one placebo-controlled trial in which glutathione was given intravenously. Improvement was recorded in 6 of 16 people in the glutathione group against 3 people in the placebo group, and the difference did not reach statistical significance. The review authors advise against intravenous glutathione for skin lightening, because its effectiveness has not been shown and side effects have been described.
The most recent review, from 2026 in the Journal of Medicine and Life, judges the data too sparse to justify routine intravenous use. It also points to the need for larger safety studies. That is why glutathione in a vial is best treated as material for laboratory research, not a ready cosmetic treatment.
How long does the effect of glutathione last?
Studies have not settled this yet, because none followed participants long after glutathione was stopped. The longest oral trial lasted 12 weeks. The 2016 review names three open questions: how long to use glutathione, how long the lightening lasts and how to maintain it. The 2025 review judges the effect of cream and capsules as moderate and hard to maintain without continued use.
| Form | Placebo-controlled trials | What was shown |
|---|---|---|
| Capsules, 250-500 mg a day | 5 randomised and 1 open-label | lower melanin index, effect over the whole body |
| Cream, 0.5-2 percent | several trials | lower melanin index where applied |
| Cream and capsules together | 1 trial from 2021 | stronger effect than either form alone |
| Intravenous infusion | 1 trial | difference not statistically significant |
What is in a glutathione vial and how much does it cost?
The shop carries glutathione 1000 mg Bio-Peptide for 30 EUR. The vial contains 1000 mg of lyophilised powder, and the pack includes two 1 ml ampoules of solvent. A thousand milligrams is enough for many portions of the size used in laboratory research. A description of the molecule and the price per milligram are on the glutathione page.
Undissolved powder is kept cool and away from light. The rules for storing the powder and the ready solution are in the guide on how to store peptides. The code under the hologram and the batch certificate let you check that the product is genuine.
Frequently asked questions
Does glutathione lighten the skin?
In placebo-controlled trials, glutathione in capsules and in cream lowered the melanin index, most clearly on the face and forearm. The effect was judged moderate.
What dose of glutathione was studied?
Oral trials used 250 mg to 500 mg a day for 4 to 12 weeks. Creams contained 0.5 to 2 percent glutathione.
How does glutathione act on skin pigment?
It inhibits tyrosinase, the enzyme that starts pigment production, and switches melanocytes from dark eumelanin to the lighter pheomelanin.
Does glutathione work on wrinkles?
In a 2017 trial, 250 mg of reduced glutathione a day for 12 weeks significantly reduced the number of wrinkles at some of the measured sites.
Does injected glutathione have a proven effect on the skin?
No. There is only one placebo-controlled trial of intravenous glutathione, and the difference in it was not statistically significant. Capsules and creams have the best data.
This is information about published research, not medical advice. The choice of treatment belongs to a doctor.
Sources
- Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. Journal of Dermatological Treatment, 2012, 23(2): 97-102. https://doi.org/10.3109/09546631003801619
- Weschawalit S, Thongthip S, Phutrakool P, Asawanonda P. Glutathione and its antiaging and antimelanogenic effects. Clinical, Cosmetic and Investigational Dermatology, 2017, 10: 147-153. https://doi.org/10.2147/CCID.S128339
- 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. International Journal of Dermatology, 2021, 60(8): 1013-1018. https://doi.org/10.1111/ijd.15573
- Dilokthornsakul W, Dhippayom T, Dilokthornsakul P. The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. Journal of Cosmetic Dermatology, 2019, 18(3): 728-737. https://doi.org/10.1111/jocd.12910
- Sarkar R, Yadav V, Yadav T et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. International Journal of Dermatology, 2025, 64(6): 992-1004. https://doi.org/10.1111/ijd.17535
- Sonthalia S, Daulatabad D, Sarkar R. Glutathione as a skin whitening agent: Facts, myths, evidence and controversies. Indian Journal of Dermatology, Venereology and Leprology, 2016, 82(3): 262-272. https://doi.org/10.4103/0378-6323.179088
- Aloraini K, Alangari A, Arif J, Alkhodairy F. Glutathione for skin lightening via intravenous, oral, and topical routes: a critical narrative review of current evidence, safety, and the evidence-practice gap. Journal of Medicine and Life, 2026, 19(7): 511-523. https://pubmed.ncbi.nlm.nih.gov/42751591/