Discovered in the early 1800s, "Hydroquinone has primarily been used as a photographic developer through history," says Jeannette Graf, M.D., assistant clinical professor of dermatology, Mount Sinai School of Medicine, New York.
Found in the leaves of many plants, especially bearberry, mountain cranberry and whortleberry berry leaves, hydroquinone also has antioxidant properties and is a component of glucoside arbutin.
"The question about its safety has been, 'Does it cause cancer?' However, there have been absolutely no reports of human malignancies linked to hydroquinone - only animal leukemias and renal adenomas (Nordlund JJ, Grimes PE, Ortonne JP. J Eur Acad Dermatol Venereol. 2006; 20(7):781-787)."
In 1978, the Food and Drug Administration (FDA) first proposed rules and recommendations to establish a monograph for miscellaneous over-the-counter (OTC) drugs, including skin-bleaching products, Dr. Graf says.
"In 1982, the FDA published a tentative final monograph for over-the-counter skin-bleaching agents. It proposed that hydroquinone in concentrations of 1.5 to 2 percent be considered generally regarded as safe and effective (GRASE) as an active ingredient in over-the-counter skin-bleaching drug products," she says.
Dr. Graf says that in 2006, however, the FDA proposed changing the classification of existing OTC skin-bleaching agents as misbranded and not GRASE. "This would also apply to any new drug products in the category, which would effectively reverse the 1982 decision. We are currently awaiting the final monograph. Presently, the FDA is getting all sorts of feedback from interested parties, including manufacturers and dermatologists who want to see over-the-counter hydroquinone products available because hydroquinone is the most effective skin-lightening agent," Dr. Graf says.
The FDA's potential reclassification of hydroquinone would affect only the OTC variety, Dr. Graf says. The agency's main concern here is for the agent's potential to cause exogenous ochronosis. In this regard, "There have only been 32 cases reported in the United States." Several nations have nixed OTC hydroquinone, including those of the European Union (in 2006). Dr. Graf says if the FDA bans OTC hydroquinone, products containing the agent will be available by prescription.
Disclosures: Dr. Graf is a consultant for Allergan, Medicis, Johnson & Johnson, Merz/BioForm, Aveeno and ROC, but she has no financial interests in any products.