Study summary · research use only
The clinical effect of glutathione on skin color and other related skin conditions: A systematic review
Plain-language summary
Paraphrased from the published abstract below — not a verdict on whether anything works.
This systematic review of human studies (healthy volunteers) examined the clinical effects of glutathione, commonly used as a skin-lightening agent in Asia, on skin color and related conditions, drawing on four included studies (three placebo-controlled RCTs, one single-arm trial; one used a topical form, others oral). Oral glutathione at 500 mg/day and topical 2.0% oxidized glutathione were both associated with lighter skin color in sun-exposed areas, measured by skin melanin index, with no significant difference in sun-protected areas. Glutathione also showed a tendency toward improved skin wrinkle, elasticity, and UV spots. Some nonserious adverse events were reported. The authors describe current evidence on glutathione's skin-lightening effect as inconclusive given study quality and inconsistent findings, though noting a trend toward lighter skin color in sun-exposed areas.
Abstract
Glutathione is one of agents which is commonly used to lighten skin color in Asia as a dietary supplement. Previous studies suggest its potential effect of glutathione on skin color. However, the clinical efficacy of glutathione in oral form is still questionable due to its limited absorption and bioavailability. To determine the clinical effects of glutathione on skin color and related skin conditions. A systematic review was conducted using PubMed, CINAHL, Scopus, EMBASE and Cochrane library were searched from inceptions to October 2017. All clinical studies evaluating the effect of glutathione on any skin effects in healthy volunteer were included. A total of four studies were included. Three studies were RCTs with placebo control, while one was a single-arm trial. One study used topical form, while others used oral form of glutathione with 250 to 500 mg/day. We found that both oral glutathione with the dosage of 500 mg/day and topical 2.0% oxidized glutathione could brighten skin color in sun-exposed area measured by skin melanin index. No significant differences in the reduction in skin melanin index were observed in sun-protected area for any products. In addition, glutathione also has a trend to improve skin wrinkle, skin elasticity, and UV spots. Some adverse events but nonserious were reported. Current evidence of the skin whitening effect of glutathione is still inconclusive due to the quality of included studies and inconsistent findings. However, there is a trend that glutathione might brighten skin color at skin-exposed area.
pepmg summarizes the peer-reviewed literature and links to every source — it sells nothing, ships nothing, and gives no medical, dosing, or human-use guidance. Don't just trust this summary: follow the citation to its source and read it yourself. Research use only.