WASHINGTON — Federal health advisers voted Monday to recommend over-the-counter sales of a weight-loss pill now sold only with a prescription.

GlaxoSmithKline Consumer Healthcare still needs final Food and Drug Administration approval before it can sell a nonprescription version of orlistat, a diet pill already marketed in prescription form as Xenical. The FDA approved the prescription version of the fat-blocking pill made by Roche in 1999.

A joint FDA advisory committee voted 11-3 to recommend approval late Monday following a daylong hearing. The agency usually follows the recommendations of its outside panels of experts, but its final decision could take months. If approved, orlistat would be the first weight-loss drug sanctioned for over-the-counter sales. Roche will continue selling Xenical regardless.

"We are excited about the potential opportunity to provide consumers with an FDA-approved over-the-counter option that promotes gradual yet meaningful weight loss," said George Quesnelle, president of GlaxoSmithKline Consumer Healthcare North America.

In six-month clinical trials, obese people who took orlistat lost on average 5.3 pounds to 6.2 pounds more than did those who were given dummy pills. Glaxo wants people to use it for only six months at a time, but as an over-the-counter item, its use would not be policed.

The pill's effect ends once its use is stopped, said Dr. Julie Golden, a medical officer in the FDA's division of metabolism and endocrinology products. A previous study showed a progressive weight gain in patients after they discontinued use of orlistat, she said. Quesnelle said people could resume use or seek help from a doctor if they gain weight.

"I think the drug is safe enough to be OTC. It's an OTC indication. Although there are some i's that need to be dotted and t's crossed, it's suitable for OTC use," panel chairman Dr. Alastair Wood said following the vote.

The panel requested that the company conduct follow-up studies if and when the drug does reach the market, as well as rework the pill's label to ensure its proper use, Wood said.

Glaxo said the drug helps the overweight slim down only when combined with a diet and exercise regimen. The drug's actual effect on weight loss is "gradual and modest," said Steve Burton, Glaxo's vice president of weight control.

"There is no magic pill for weight loss and orlistat is not a magic pill. Orlistat is a tool that will help people control their calorie intake and modify their diet," said John Dent, the pharmaceutical company's senior vice president of research and development.

Dr. Sidney Wolfe of the watchdog group Public Citizen urged the panel to reject the company's application, calling it a "desperate attempt to revive this barely effective drug by an OTC switch."