arbutin

Arbutin is a glycosylated hydroquinone, specifically hydroquinone linked to a glucose molecule. It occurs naturally in several plants, most notably bearberry (Arctostaphylos uva-ursi), and exists in two stereoisomeric forms: alpha-arbutin and beta-arbutin. Its chemical formula is commonly cited as C12H16O7.

In cosmetics and dermatology, arbutin is used as a skin-lightening agent due to its ability to influence melanin production. It is considered a tyrosinase inhibitor, the enzyme responsible for a key step in melanin synthesis. In the skin, arbutin may act as a competitive inhibitor and, upon enzymatic hydrolysis, can release hydroquinone, which also contributes to its depigmenting effect. The two isomers differ in stability and activity, with alpha-arbutin generally described as more stable and often more potent in topical applications.

Applications include creams, serums, and lotions intended to treat hyperpigmentation, age spots, and melasma. Usage levels in products vary by regulation and formulation, with manufacturers selecting concentrations that balance efficacy and safety.

Safety and regulatory considerations vary by jurisdiction. Arbutin is generally regarded as safer than hydroquinone, but concerns exist about the potential release of hydroquinone in the skin. Regulatory assessments have evaluated alpha- and beta-arbutin for cosmetic use and established usage limits or data requirements in many regions. As with all active cosmetic ingredients, products should be used according to label directions, and ingestion or improper use should be avoided.