Hydroquinone for Hyperpigmentation: A Comprehensive Review of Efficacy, Safety, and Current Perspectives

Hyperpigmentation, a prevalent dermatological concern, manifests as the excessive accumulation of melanin, resulting in noticeable dark patches on the skin. This condition encompasses various clinical presentations, including melasma, post-inflammatory hyperpigmentation, and solar lentigines, each arising from distinct etiological factors. Hydroquinone, a phenolic compound, has served as a cornerstone in the topical management of hyperpigmentation for over half a century, primarily exerting its effects through the reversible inhibition of tyrosinase, a crucial enzyme in the melanogenesis pathway. This literature review synthesizes the current understanding of hydroquinone’s efficacy across different hyperpigmentation types, drawing from studies published between 2015 and 2025. The analysis reveals that hydroquinone, particularly at concentrations of 2–4%, demonstrates significant effectiveness in reducing pigmentation associated with melasma and post-inflammatory hyperpigmentation. However, its use is not without limitations, as evidenced by common side effects such as skin irritation and the rare but potentially disfiguring risk of ochronosis with prolonged, unsupervised application. The review further explores the role of hydroquinone in combination therapies, notably its synergistic effects with retinoids and corticosteroids in the widely recognized triple combination cream for melasma. A critical comparison with emerging alternative treatments, including tranexamic acid, kojic acid, and arbutin, highlights the evolving landscape of hyperpigmentation management. Finally, the review provides an overview of the current regulatory status of hydroquinone in the United States, Europe, and other regions, reflecting the ongoing safety considerations and the shift toward prescription-based availability in many areas. The importance of concomitant photoprotection and potential future research directions are also discussed.