BOSTON -- The Food and Drug Administration is proposing a ban on over-the-counter skin-lightening creams. Researchers said the creams could put users at risk.

NewsCenter 5's Heather Unruh reported that the creams claim to make users look better by erasing age spots and scars by lightening skin.

The creams in question contain a drug called hydroquinone, a possible carcinogen. It's found in about 130 products on the market that are sold in stores and online.

The FDA said it is concerned because some studies show evidence that hydroquinone caused cancer in rodents.

Skin researcher Dr. Ethan Lerner said he isn't very concerned with the cancer risk.

"The cancer has only been in animals. I think the risk in people is small," he said. "From my view, the pigmentation problem is more problematic than the cancer one."

In fact, the FDA also warned that hydroquinone has been linked to a condition that disfigures the skin. Which is why, under the FDA ban, all skin bleaching products would only be given to patients under medical supervision.

Lerner said that is a good idea.

Lerner, a Boston University dermatologist, prescribes hydroquinone to patients every day. He said not everyone will suffer side effects.

"Darkly pigmented patients are more at risk because they use it for longer periods of time," Lerner said.

The FDA admitted that the risk of using the drug is not known and more testing needs to be done. The administration warned that for now, the drug should only be used under medical supervision.

NewsCenter 5 went to a local drug store and found that many of the major skin-lightening brands do not contain the ingredient hydroquinone. Patients with questions about hydroquinone should talk to their doctors.