The FDA cites the possible risk of cancer and skin discoloration from hydroquinone typically found in these products.
However, those cancer studies were done on rats, not people.
"The actual risk to humans from use of hydroquinone has yet to be fully determined," the FDA states in its proposal, published in the U.S. government's Federal Register.
The type of skin discoloration noted by the FDA is called exogenous ochronosis, a darkening of the skin. The FDA cites research linking the condition to hydroquinone use.
The FDA isn't proposing a ban on prescription skin bleaching drug products. But all such products would need to submit a new drug application for the FDA's review.
Not all skin lighteners contain hydroquinone. The FDA knows of 200 products containing hydroquinone in strengths from 0.4% to 5%, about two-thirds of which "appear to be marketed as OTC [over-the-counter] drugs," says the FDA.
The FDA is taking comments on its proposal until Dec. 27.
WebMD spoke with dermatologist Susan Taylor, MD, of Society Hill Dermatology in Philadelphia, and the Skin of Color Center in New York about the FDA's proposal.
"I feel that hydroquinones are safe and effective treatment for pigmentary disorders," Taylor says. "I feel comfortable recommending that my patients continue to use hydroquinones if they have a pigmentary disorder."
"I think the evidence is quite weak with the link between hydroquinones and cancer," Taylor tells WebMD.
"Data on rats and mice cannot necessarily be extrapolated to human data," she says.
"In Africa, people have used hyrdoquinones for long periods of time ... meaning years, 10, 20, 30, years ... and at high concentrations," Taylor says. "We've not seen a proliferation of various types of cancers reported from that population.
Exogenous ochronosis is rare in the U.S., Taylor notes.
"If you look at the case reports, it's probably less than 200," Taylor says. "So it's really not a significant problem here in the United States."
Millions of Users
Taylor points out that "many patients have disorders that are truly disfiguring and devastating. And these conditions can be improved significantly with hydroquinone products."
"It's important therapy and it's used by millions and millions of people," Taylor says.
She says hydroquinone products are primarily used to lighten dark areas of the skin due to conditions including injury, rashes, acne, and sun damage.
"So there are real problems and this is a real solution," Taylor says. She adds that filing new drug applications can cost millions of dollars.
"My concern is that we could lose prescription products that we have," Taylor says. "That would have major consequences, I think."
"It's safe, effective; it's the gold standard, and I think our patients would benefit from continued use for these problems. I think those three points sum it up for me," Taylor says.
SOURCES: U.S. Government Printing Office, Federal Register, Aug. 29, 2006; vol 71: pp 51146-51155. Susan Taylor, MD, Society Hill Dermatology, Philadelphia, Skin of Color Center, New York.
By Miranda Hitti
Reviewed by Brunilda Nazario