Glutathione is sold for brighter, lighter or more even skin. It comes as pills, creams and IV drips. You probably want to know two things. Does it work? And which form, if any?
The trials give a clearer answer than you might expect. The small forms show small effects. The dramatic form, the drip, has the least behind it. The molecule is covered in the glutathione guide, under the longevity goal.
Why glutathione would affect skin color
Tyrosinase is an enzyme the skin uses to make melanin, its main pigment. The authors of one trial describe reduced glutathione as lightening skin by blocking tyrosinase [3].
That is the theory. The trials below measured the melanin index, a device reading of skin pigment. None of them measured whether people were happier with their skin.
Oral glutathione: pills and capsules
The first placebo-controlled trial enrolled 60 healthy medical students in Bangkok [1]. Half took 500 mg of glutathione a day, split into two doses. Half took placebo. The trial lasted 4 weeks.
Melanin readings dropped at all six sites measured. The drop beat placebo at two of them: the right side of the face (p = 0.021) and the sun-exposed left forearm (p = 0.036). Both groups tolerated their capsules well.
The authors were careful. They wrote that oral glutathione lightened skin in a small number of people. They added that long-term safety had not been established [1].
A later 12-week trial tested a lower dose, 250 mg a day, in healthy women [2]. It compared reduced glutathione, oxidized glutathione and placebo. Melanin and UV spots tended to be lower on both forms. Some wrinkle measures improved on reduced glutathione. There were no serious side effects.
Topical glutathione: creams and lotions
A 10-week trial had 30 women aged 30 to 50 treat each side of the face differently [3]. One side got a 2% oxidized glutathione lotion twice a day. The other side got a placebo lotion.
The treated side had a lower melanin index from the early weeks on. By week 10 the gap was clear (P<0.001). Skin moisture, smoothness and wrinkles also improved later in the trial. No marked side effects were reported.
A 2025 review of topical glutathione found five clinical trials in total [5]. It called the results promising. It also said safety data are limited and more randomized trials are needed. For other peptides used on skin, see which peptides for skin have human trials.
What a systematic review concluded
A 2025 systematic review graded the evidence across forms [4]. It found five randomized trials and one open study of oral glutathione. All showed a lower melanin index than placebo, at 250 mg to 500 mg a day.
Topical glutathione at 0.5% beat both 0.1% and placebo. Combining a 2% cream with oral glutathione beat either alone. The review’s summary is balanced: both forms work moderately, but the effects do not last and the costs vary [4].
IV glutathione drips
IV glutathione is where the marketing is loudest and the evidence is thinnest. The same review found only one placebo-controlled IV trial. [4]
In it, 6 of 16 people responded on glutathione, or 37.5%, against 18.7% on placebo. The p-value was 0.054, just short of the usual bar. The review concluded that IV glutathione is contraindicated for lightening, because of lack of efficacy and side effects [4].
A 2016 review raised a longer-term question [6]. Glutathione may shift skin pigment from brown toward red melanin. The authors suggest that could raise sun-related skin cancer risk. That is a concern they raise, not a measured result.
What this means for you
If you want to try glutathione for skin, the trials favor the modest forms. Oral and topical glutathione showed small, measurable changes over weeks. The 2025 review calls those effects unsustainable [4].
The IV drip has one trial, and it missed significance. Whether a pill reaches your blood at all is covered in whether oral glutathione raises levels in the body.