What is the effect of glutathione on skin whitening?

From the Guidelines

Glutathione whitening products are not recommended for skin lightening due to limited scientific evidence supporting their effectiveness and potential safety concerns. Glutathione is a naturally occurring antioxidant in the body that some believe can lighten skin when taken orally, applied topically, or injected. However, the FDA has not approved injectable glutathione for skin lightening, and oral supplements may not effectively increase glutathione levels in the skin.

Key Points to Consider

• The provided evidence does not support the use of glutamine or glutathione for skin lightening or whitening, as the studies primarily focus on radiation-induced diarrhea, mucositis, and skin toxicity, as well as the management of vitiligo 1.
• If you're concerned about skin discoloration or hyperpigmentation, safer alternatives include topical treatments containing ingredients like hydroquinone (2-4%), kojic acid, vitamin C, niacinamide, or retinoids, which have better evidence for effectiveness 1.
• These treatments should be used with daily broad-spectrum sunscreen (SPF 30+) to prevent further darkening.
• The desire for skin lightening often stems from cultural beauty standards, but it's essential to understand that skin tone variations are natural and healthy.
• If you're experiencing unusual skin changes, consult a dermatologist who can provide personalized advice and rule out any underlying medical conditions.

Important Considerations

• The use of glutathione for skin whitening is not supported by strong scientific evidence, and its safety and efficacy are not well established.
• Topical treatments with proven effectiveness, such as hydroquinone, kojic acid, and retinoids, are preferred for managing skin discoloration and hyperpigmentation.
• Sun protection is crucial in preventing further skin darkening and promoting overall skin health.

From the Research

Glutathione Whitening Effects

• The clinical effect of glutathione on skin color and other related skin conditions has been studied, with results showing that both oral glutathione with a dosage of 500 mg/day and topical 2.0% oxidized glutathione could brighten skin color in sun-exposed areas measured by skin melanin index 2.
• However, the current evidence of the skin whitening effect of glutathione is still inconclusive due to the quality of included studies and inconsistent findings 2.
• Glutathione has anti-melanogenic and antioxidant properties, which led to its use as a skin-lightening agent, but its efficacy and safety as a skin-whitening agent are still debated 3, 4, 5, 6.

Forms of Glutathione Administration

• Topical glutathione, particularly glutathione 0.5%, has been shown to be significantly more effective compared to glutathione 0.1% and placebo in skin lightening 4.
• Oral glutathione at doses of 250 mg once a day, 250 mg twice a day, and 500 mg once a day has been shown to reduce the melanin index compared to placebo 4.
• Intravenous glutathione is contraindicated due to lack of efficacy and side effects 4.
• Parenteral glutathione preparations have been associated with adverse effects, whereas oral preparations have been well tolerated 5, 6.

Safety and Efficacy

• The safety profiles of oral glutathione preparations have been well tolerated, but more research is needed to determine the longevity of skin-lightening effects and maintenance protocols 2, 5, 6.
• The use of intravenous glutathione injections has been warned against by the Food and Drug Administration of Philippines due to adverse effects and lack of evidence to prove its efficacy 6.
• More randomized, double-blind, placebo-controlled trials with larger sample size, long-term follow-up, and well-defined efficacy outcomes are warranted to establish the relevance of glutathione in disorders of hyperpigmentation and skin lightening 2, 3, 4, 5, 6.