Hydroquinone derivative isolated from the leaves of the bearberry shrub, cranberry, blueberry, some mushrooms, and most types of pears. Because of arbutin’s hydroquinone content, it can have melanin-inhibiting properties. Although the research describing arbutin’s effectiveness is persuasive (even though most of the research has been performed on animals or in vitro), concentration protocols have not been established. That means we just don’t know how much arbutin it takes to have an effect in lightening the skin. Many cosmetics companies use plant extracts that contain arbutin, such as bearberry and mulberry leaf extract, but again, there is limited research, mostly animal studies or in vitro, showing that the arbutin-containing plant extracts used in skin-care products have any impact on skin. Whether or not these extracts are effective in the small amounts present in cosmetics has not been established (Sources: Phytotherapy Research
, July 2004, pages 475–479; Biological & Pharmaceutical Bulletin
, April 2004, pages 510–524; Clinical and Experimental Dermatology
, September 2002, pages 513–515; Analytical Biochemistry
, June 2002, pages 260–268, and June 1999, pages 207–219; Pigment Cell Research
, August 1998, pages 206–212; and Journal of Pharmacology and Experimental Therapeutics
, February 1996, pages 765–769).