Role of Antioxidants in Melasma: A Systematic Review

Melasma is a common skin disorder characterized by facial hyperpigmentation, often aggravated by sun exposure. Antioxidants are being studied as a treatment option for their potential to reduce oxidative stress and improve skin pigmentation. A comprehensive literature search was conducted in PubMed for articles published over the past decade, up to January 31, 2024, on the use of antioxidants in melasma treatment. The systematic review, conducted by two independent investigators, included 30 studies on antioxidants in melasma, covering vitamin C, cysteamine, silymarin, PLE, tomato extract/lycopene, zinc sulfate, melatonin, and other antioxidants. Findings indicated that combining vitamin C with physical therapies, such as peels and lasers, yielded better results. Cysteamine, a naturally occurring aminothiol, showed efficacy comparable to hydroquinone with fewer side effects. Silymarin was effective in reducing melasma severity with minimal adverse effects. PLE showed mixed results but potential as an effective antioxidant when combined with other treatments. Lycopene from tomato extract demonstrated significant improvements in melasma when used as an adjuvant therapy. Zinc sulfate showed some effectiveness but was less potent than hydroquinone. Melatonin had antioxidant capabilities but showed no statistically significant improvement. Glutathione is emerging as a new antioxidant therapy showing efficacy in melasma in combination with other topicals and microneedling. Other antioxidants, including combinations of vitamins C, E, and ferulic acid, showed potential as adjuncts in melasma treatment. These findings highlight the diverse efficacy of antioxidants in managing melasma, suggesting their potential as safe and effective treatments.