Arbutin is a naturally occuring derivative of hydroquinone found in the leaves of cranberry, bearberry, and blueberry shrubs, most types of pears, and many other plants. Arbutin may inhibit melanogenesis by affecting tyrosinase activity.
Arbutin has been used in the treatment of disorders of hyperpigmentation such as postinflammatory hyperpigmentation caused by acne, trauma, allergic reactions, infections, injuries, phototoxic reactions, reactions to medications, reactions to cosmetics, and inflammatory diseases.
Arbutin concentration protocols for skin whitening have not yet been established. Low concentrations have no effect, while high concentrations of about 5% or more can be as irritating as hydroquinone and may potentially result in unexpected hyperpigmentation (darkening).
Shiseido patented the use of Arbutin in skin-whitening cosmetics. Some companies bypass the patents by using Arbutin-containing plant extracts such as bearberry. There is inadequate research data showing that Arbutin extracted from plants has any skin whitening effects.