All About Alli, the Weight Loss Pill (cont.)

The pills cost about $1.50 to $2 a day. A 60-count starter kit retails for $49.25 and a 90-count kit costs $62.99 at www.drugstore.com. GlaxoSmithKline is working with state insurers to get some of the costs covered by insurance.

A Magic Bullet?

If you take Alli and follow a sensible low-fat diet and exercise, you will lose 50% more weight than you would with diet and exercise alone. Instead of losing 10 pounds, a person who takes Alli will lose 15 pounds.

"It's an exciting new tool and widely available, but to think this is the only thing or some magic quick fix is wrong," says Gary Foster, MD, director of the Center of Obesity Research and Education at Temple University in Philadelphia, who helped develop the Alli program. "For the same amount of effort [as with a traditional diet and exercise plans], you get 50% more weight loss. It makes it easier, not effortless," he tells WebMD.

"Alli is an add-on," says George Blackburn, MD, PhD, director of the Center for the Study of Nutrition Medicine at the Beth Israel Deaconess Medical Center in Boston. "You have to have a good lifestyle with diet and exercise."

GlaxoSmithKline even makes the point on its web site devoted to the drug that it "only works if you work" and that it is "not a miracle pill or a quick fix."

In the recommended Alli diet, one-third of the calories come from fat, one-third come from protein, and the final third comes from carbs.

"Do the things you need to do to lose weight and see if this won't make it that much more successful," Blackburn tells WebMD.

"It's not about a pill, it's about a program," agrees Valentine Burroughs, MD, MBA, chief medical officer and chairman of the department of medicine at North General Hospital in New York City. Burroughs participated in developing the Alli program.

How Alli Works

The new drug is not an appetite suppressant. Instead, Alli works by blocking the absorption of fat in the gastrointestinal (GI) tract. But the blocked fat has to go somewhere, which is why many a candid commentator has said not to take Alli on a first date or wear white pants while taking it.

A GlaxoSmithKline executive, speaking at a news conference in New York City, called the untoward GI effects a positive feedback tool to help people modify their eating habits. Put another way: eat a high-fat meal, have an "accident" -- and you will be less likely to do it again.

"If you think a Quarter Pounder with cheese is low fat compared with Big Mac, you will get some feedback," Foster tells WebMD. For this reason, Alli is not a good combination with a high-fat, low-carb diet. In addition, if your diet is too low in fat, there's no fat to be blocked.

Prescription-strength Xenical contains 120 milligrams while Alli contains 60 milligrams. But the side effects are not necessarily halved, Foster says.