The Role of Glutathione as a Bleaching Agent in Whitening Skin: A Review

Objective: To review and compare the efficacy of glutathione formulations as skin-whitening agents in adults participating in several clinical studies. Methods: Using a MEDLINE search with the time frame specified up to March 2020 , seven clinical studies involving GSH use for lightening the skin were recognized and assessed for significance and validity. Results: Four controlled clinical trials (GSH capsules: 60 healthy volunteers; 250 mg oral GSH capsules:60; 2% glutathione lotion: 30s healthy volunteers; GSH as wash:74 healthy volunteers) and a case series(GSH lozenges: 30 patients) showed a significant reduction in melanin index. A case series (GSH soap: 15 patients) revealed a skin-lightening effect based on photography. Only one placebo-controlled study on IV GSH (1200 mg) in 60 healthy volunteers demonstrated a poor effect of glutathione as a whitening agent. Conclusion: The literature search revealed that glutathione is not useful enough as a skin-whitening agent, as it is only effective on some parts of the skin and did not present any long-lasting effect. Although the safety profile of topical and oral glutathione seemed to be good, long-term research studies employing better study design are required in order to evaluate the efficacy of this antioxidant.