Jan Marini, chief executive of the closely held San Jose, Calif., firm, said her representatives started notifying customers late last week that it would no longer sell Age Intervention Eyelash Conditioner in the U.S. Marini and several other companies sell eyelash products that contain ingredients that are similar to those in prescription drugs for an eye disease.

In November, the FDA dispatched agents to seize several thousand tubes of a similar, discontinued Jan Marini product that the agency called a "misbranded drug." The FDA hasn't acted against the reformulated version of the product that the Marini firm is now withdrawing from the U.S. market. Ms. Marini says she isn't aware of any safety complaints related to either the original formulation or the new one.

Ms. Marini said the decision will allow her to focus her attention on the rest of her skin-care products business. She said she doesn't know if the FDA will allow sales of eyelash conditioners like hers that blur the line between cosmetics and drugs, but "I don't think this issue is going away."

Another concern for the company was a burgeoning conflict with Allergan over patents. Allergan, which is believed to be testing an eyelash product called Lumilash, modeled on its glaucoma drug Lumigan, in November sued seven eyelash-product companies alleging patent infringement.

"It's unfortunate that this product is no longer available from Jan Marini because it truly does grow the eyelashes and has a quantifiable benefit," unlike many so-called cosmeceuticals, said Joel Schlessinger, an Omaha, Neb., dermatologist who sells it in his office and on his LovelySkin.com Web site. Confusion over its regulatory status shows the need for a third regulatory track for cosmeceuticals, separate from those for drugs and cosmetics, he added.

Last week, Allergan said it has dropped one of the lawsuit defendants upon assurance that its product uses a different mechanism that doesn't violate Allergan patents. Underscoring its intention to aggressively defend "the fruits of our scientists and other hard work," Allergan said it has "no intention of settling any case in a manner that would empower a defendant to continue to infringe our intellectual property portfolio."

Jan Marini Skin Research doesn't disclose financial results, but Ms. Marini said the eyelash conditioner product has been its top seller and accounted for roughly 30% of sales. The tubes have typically sold for $160 in physician offices, spas and online.