Protocols › Glutathione

Glutathione for lighter skin

Goal: What trials of glutathione by mouth used to lighten skin colour, and how strong their results are.

Each protocol describes what studies used, for one goal or for one group of people. It is not advice for you: talk to a doctor before you start a supplement.

Updated 10 Nov 2026
Dose

250 mg once or twice a day, or 500 mg once a day, in the trials of a 2025 review.[1] One trial split 500 mg a day into two doses.[2]

Form

Glutathione by mouth, in one trial as capsules.[2] In one trial, 250 mg of glutathione with 500 mg of L-cystine worked better than either one alone.[3]

How long

4 to 12 weeks.[2][3]

What studies found

A 2025 review found 5 randomized trials in which glutathione by mouth lowered the melanin index, a measure of skin pigment, more than placebo.[1] A 2019 review called the evidence inconclusive and saw a trend toward lighter skin only in areas exposed to the sun.[4]

Ask a doctor first

Long-term safety of glutathione for skin lightening has not been established.[2] Glutathione into a vein for this use lacked effect and caused side effects.[1] EFSA's safety assessment of S-acetyl glutathione did not cover pregnant or breastfeeding women.[5]

People who are pregnant or breastfeeding should ask a doctor or pharmacist first.[5]

References

  1. Glutathione as a skin-lightening agent and in melasma: a systematic review. Sarkar R, Yadav V, Yadav T, P J, Mandal I Int J Dermatol, 2025. PMID 39444151
  2. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. Arjinpathana N, Asawanonda P J Dermatolog Treat, 2012. PMID 20524875
  3. The effects of the oral supplementation of L-Cystine associated with reduced L-Glutathione-GSH on human skin pigmentation: a randomized, double-blinded, benchmark- and placebo-controlled clinical trial. Duperray J, Sergheraert R, Chalothorn K, Tachalerdmanee P, Perin F J Cosmet Dermatol, 2022. PMID 33834608
  4. The clinical effect of glutathione on skin color and other related skin conditions: A systematic review. Dilokthornsakul W, Dhippayom T, Dilokthornsakul P J Cosmet Dermatol, 2019. PMID 30895708
  5. Safety of S-acetyl glutathione as an novel food pursuant to Regulation (EU) 2015/2283. Turck D, Bohn T, Cámara M, Castenmiller J, De Henauw S, Jos Á, et al. EFSA J, 2026. PMID 42683004