Washington ? Fat Americans may be just months away from gaining a new ally in the battle of the bulge.

The fat-blocking pill, already named Alli, is meant to help the overweight and obese shed pounds as part of an overall diet and exercise program.

A panel of experts voted 11-3 late Monday to recommend that the Food and Drug Administration approve sales of the pill without a prescription. The drug is formally called orlistat and is already available for sale in prescription form as Xenical.

The FDA still needs to sign off on the recommendation. It usually follows the advice of its outside panels of expert scientists and doctors.

If the FDA does OK the pill, it would become the first agency-sanctioned weight-loss drug available for purchase without a prescription.

Alli would have half the dosage of Xenical, but would be freely available for purchase by adults. GlaxoSmithKline Consumer Healthcare estimates 5 million to 6 million overweight Americans could buy the pills, which would cost $12 to $25 a week.

The prescription form, approved by the FDA in 1999, would continue to be sold by Roche.

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. Once patients stopped taking the pills, they regained some of that lost weight, said Dr. Julie Golden, a medical officer in the FDA’s division of metabolism and endocrinology products. Quesnelle said people could resume taking the pills or seek help from a doctor if they gain weight.

The panel requested that the company conduct follow-up studies if the drug does reach the market, as well as rework the pill’s label to ensure its proper use, panel chairman Dr. Alastair Wood said following the vote.

“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,” said Wood, who spoke earlier of the drug’s “underwear problem.”

Orlistat acts by blocking the absorption of about one-quarter of any fat consumed in a meal. That fat – the equivalent of about 150 to 200 calories – is passed out of the body in stools, which can be loose or oily as a result. Other side effects include fecal incontinence, gas and oily spotting of undergarments. About half of patients in trials experienced such side effects, the company said.

Eating less fat helps control those side effects and cuts the intake of calories, it added.