Written by Shereen, Product Management Associate · Updated 11 November 2026

Glutathione is an antioxidant your body already makes, and it has a growing set of placebo-controlled trials behind it for skin tone, many of them in Asian adults.

Here's what those trials found, how glutathione works on pigment, how long it takes, and how to choose a form that fits your day.

→ See SkinBright Thins, our glutathione strip that melts on the roof of your mouth

What is glutathione?

Glutathione is a small antioxidant molecule your cells make from three amino acids: glutamate, cysteine and glycine. It protects cells from oxidative damage and helps keep their chemistry in balance.^[1]

It's the most abundant antioxidant your body makes, and daily supplements can raise it. In a 6-month placebo-controlled trial of 54 adults, 1,000 mg of oral glutathione a day raised levels in red blood cells, plasma and immune cells by 30 to 35%.^[2] For its roles beyond skin, read our guide to glutathione, the body's master antioxidant.

How does glutathione brighten skin?

Glutathione works on melanin, the pigment that gives skin its colour, at several points in the process that makes it. Researchers have proposed a number of ways it does this, and these are three of the main ones:^[3]

• It slows tyrosinase. Tyrosinase is the enzyme that drives melanin production. Glutathione binds to the copper at its active site, which switches it off.^[3]
• It changes the type of pigment made. Glutathione shifts pigment cells towards phaeomelanin and away from eumelanin, the darker of the two types.^{[3] [4]}
• It mops up free radicals. Free radicals and peroxides help switch tyrosinase on, and glutathione neutralises them.^[3]

Because glutathione works on pigment as it's being made, its effect on skin tone builds with daily use over several weeks, as the trials below show.

Does oral glutathione work for skin?

Yes. A 2025 systematic review found that five randomised controlled trials and one open study of oral glutathione, at 250 mg once or twice a day or 500 mg once a day, showed a significant drop in the melanin index, a measure of the pigment in skin.^[5] Here are the key trials:

• 500 mg a day for 4 weeks (randomised, placebo-controlled). In 60 healthy medical students in Bangkok, who took their capsules as two doses a day, melanin readings fell at all six skin sites measured. The drop was significantly greater than with placebo at two of the six sites, the right side of the face and the sun-exposed left forearm, and changes in UV spots followed a similar pattern. Glutathione was very well tolerated.^[6]
• 250 mg a day for 12 weeks (randomised, placebo-controlled). In 60 women aged 20 to 50, melanin readings and UV spots on the face and arms tended to be lower than with placebo. In the women over 40, readings on the sun-exposed right forearm were significantly lower than with placebo.^[7]
• Glutathione with L-cystine for 12 weeks (randomised, placebo-controlled). In a trial of 124 Asian women, the group taking 250 mg of glutathione with 500 mg of the amino acid L-cystine each day had significantly lighter skin than the placebo group after 12 weeks. Their facial dark spots also got smaller after 6 and 12 weeks.^[4]
• A glutathione lozenge for 8 weeks (open study). In 30 Filipino women with skin types IV and V, a lozenge dissolved in the mouth each day lowered melanin readings significantly from where they started, with changes showing from 2 weeks. There were no serious side effects.^[8]
• Glutathione by mouth plus a glutathione cream for 8 weeks (randomised, placebo-controlled). In 46 people in Indonesia, oral glutathione used together with a glutathione cream gave significantly lower melanin readings than placebo.^[11]

The clearest results were on sun-exposed skin, such as the face and forearms.^{[6] [7]}

Which form of glutathione is best: capsule, liposomal or dissolving strip?

Capsules, liposomal glutathione and mouth-dissolving tablets and lozenges all have human research behind them. Capsules were used in two of the placebo-controlled skin trials above, liposomal glutathione raised blood levels within a week, and a tablet dissolved in the mouth raised them within 30 minutes.^{[9] [10]}

Capsule: placebo-controlled trials and a systematic review.^{[5] [6] [7]} Liposomal: pilot study.^[9] Lozenge and tablet: absorption and skin studies.^{[8] [10]} Cream: randomised controlled trial and systematic review.^{[5] [11]}

Glutathione absorbed through the lining of the mouth skips the enzyme in the gut that breaks down some swallowed glutathione.^[10] For a closer look at how each form is absorbed, read our guide: Does oral glutathione absorb? Forms compared. This article covers glutathione you take by mouth or apply to your skin; injections are a medical procedure and aren't covered here.

How long does glutathione take to work?

In trials, changes in skin tone showed from 2 to 4 weeks of daily use, with results measured up to 12 weeks. Glutathione levels in your blood rise much sooner.^{[6] [8] [10]}

• 30 minutes: blood glutathione rose 30 minutes after a glutathione tablet dissolved in the mouth, and was still higher at 60 minutes.^[10]
• 1 to 2 weeks: daily liposomal glutathione raised blood levels within 1 week, with the biggest rise at 2 weeks.^[9] In the lozenge study, melanin readings fell from 2 weeks.^[8]
• 4 weeks: 500 mg a day lowered melanin readings on the face and a sun-exposed forearm more than placebo.^[6]
• 6 weeks: facial dark spots got smaller with glutathione and L-cystine.^[4]
• 12 weeks: significantly lighter skin with glutathione and L-cystine in a trial of 124 Asian women, and lower melanin readings on a sun-exposed forearm in women over 40.^{[4] [7]}

Daily use is what counts. In the 6-month trial, glutathione stores mostly rose with time and dose, and settled back to where they started a month after people stopped.^[2] That's why we suggest giving glutathione at least 12 weeks of daily use before you judge your results.

How do you get the best results from glutathione under Singapore's sun?

Pair it with daily sun protection. The National Environment Agency notes that Singapore's UV index commonly reaches Very High and Extreme levels between 11am and 3pm on days with little cloud.^[12]

1. Sunscreen every morning. The American Academy of Dermatology says treatment for dark spots begins with sunscreen: broad-spectrum, SPF 30 or higher, reapplied every 2 hours and after sweating.^[13]
2. Glutathione every day. Pick a time you'll remember, as steady daily use builds your glutathione stores.^[2]
3. A glutathione cream, if you like. A 2025 review found that oral and topical glutathione together worked better than either one alone.^{[5] [11]}

If you'd like to support your skin against UV from within too, Snow Tomato Glowjuice is our white tomato skin drink, and our guide to snow tomato's benefits for your skin explains how its colourless carotenoids work. For patches that darken in the heat, read our guide to melasma and pigmentation under the Singapore sun.

How do you choose the best glutathione supplement in Singapore?

Choose a clear dose close to what the trials used, in a form you'll happily take every day. Check the label for:

• The dose: skin trials used 250 to 500 mg of glutathione a day.^[5]
• The form: L-glutathione, also called reduced glutathione, was used in both 12-week skin trials.^{[4] [7]}
• The delivery: capsules suit people who are happy to swallow pills, while liposomal and mouth-dissolving forms raised blood glutathione quickly in studies.^{[9] [10]}
• Ease: results build with daily use, so pick a format that fits your day, at home or on the go.^[2]

Our SkinBright Thins gives you 200 mg of 90% pure liposomal L-glutathione in each cranberry mint strip. It uses a dual-delivery system: the thin melts on the roof of your mouth, so glutathione can be absorbed through the lining of your mouth, and the glutathione itself is liposomal, to preserve its stability and potency. Place it on the roof of your mouth rather than your tongue and let it dissolve, with no water and no pill to swallow. Each thin also contains vitamin C, zinc, selenium, magnesium, milk thistle, hyaluronic acid and L-cysteine. Take 1 thin a day, at any time of day; each box holds 15.

Shop SkinBright Thins

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Related reading: Does oral glutathione absorb? Forms compared · Glutathione beyond skin: the master antioxidant · Melasma and pigmentation under the Singapore sun

Frequently asked questions

Is glutathione safe to take every day?
In skin trials, oral glutathione at 250 to 500 mg a day was well tolerated, with no serious side effects reported over 4 to 12 weeks. A 6-month trial gave healthy adults up to 1,000 mg a day. If you're pregnant, breastfeeding, on medication or have allergies, check with your doctor first.

What time of day should I take glutathione?
Take it at a time you'll remember, as daily use matters more than timing. In one 12-week trial, women took their glutathione once a day at bedtime. SkinBright Thins can be taken at any time of day and needs no water, so you can take it at home or on the go.

Can glutathione help with wrinkles?
It may. In a 12-week placebo-controlled trial in women aged 20 to 50, 250 mg of glutathione a day led to significantly fewer wrinkles than placebo at some skin sites measured on the arms, and skin elasticity tended to improve. The researchers concluded that glutathione may also have anti-ageing benefits for skin.

Does glutathione work on Asian skin?
Yes. The main skin trials in this article were done in Asian adults: two in Thailand, one in the Philippines, one in Indonesia and one in 124 Asian women. Together they found lower melanin readings with daily glutathione, and lighter skin and smaller facial dark spots when it was taken with L-cystine, which makes the research especially relevant to skin in Singapore.

How do I take SkinBright Thins?
Take 1 thin a day: place it on the roof of your mouth and let it melt slowly. Keep it off your tongue, so the glutathione is absorbed through the lining of your mouth rather than swallowed. You don't need water, and each box holds 15 thins, a 15-day supply.

References
[1] Forman HJ et al. Glutathione: overview of its protective roles, measurement, and biosynthesis. Mol Aspects Med. 2009.
[2] Richie JP Jr et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015.
[3] Villarama CD, Maibach HI. Glutathione as a depigmenting agent: an overview. Int J Cosmet Sci. 2005.
[4] Duperray J et al. 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. J Cosmet Dermatol. 2022.
[5] Sarkar R et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol. 2025.
[6] Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. J Dermatolog Treat. 2012.
[7] Weschawalit S et al. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol. 2017.
[8] Handog EB et al. An open-label, single-arm trial of the safety and efficacy of a novel preparation of glutathione as a skin-lightening agent in Filipino women. Int J Dermatol. 2016.
[9] Sinha R et al. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. Eur J Clin Nutr. 2018.
[10] Buonocore D et al. Bioavailability study of an innovative orobuccal formulation of glutathione. Oxid Med Cell Longev. 2016.
[11] Wahab S et al. Combination of topical and oral glutathione as a skin-whitening agent: a double-blind randomized controlled clinical trial. Int J Dermatol. 2021.
[12] National Environment Agency. UV radiation and UV index. Updated 8 April 2026.
[13] American Academy of Dermatology. How to fade dark spots in darker skin tones. Updated 10 March 2025.

These statements have not been evaluated by any regulatory authority. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult a healthcare provider before use if you are pregnant, breastfeeding, or on prescribed medication.