All About Alli, the Weight Loss Pill

Experts explain the benefits and side effects of the over-the-counter diet drug.

By Denise Mann
WebMD Feature

Reviewed By Louise Chang, MD

By now, you have probably seen the commercials or read the direct mail pieces about Alli. They ask if you are ready to commit to a weight loss plan that includes Alli, the over-the-counter version of the FDA-approved fat blocker formerly known as Xenical.

The name has changed -- and the over-the-counter version is one-half the strength of Xenical -- but it's the same drug. And it has some of the same problematic side effects that plagued its prescription-strength predecessor -- gas with oily discharge, inability to control bowel movements, oily or fatty stools, and oily spotting.

Alli (pronounced "ally" -- as in friend or associate) hits drug stores on Friday, June 15. And as its name suggests, Alli is merely one component of a new weight loss program.

More than just a pill, the Alli program involves a reduced-calorie, low-fat diet, regular walking and toning exercises, and behavioral changes. It comes with a companion book called Are You Losing It? Losing Weight Without Losing Your Mind, along with other weight loss material and online support. The drug's manufacturer, GlaxoSmithKline, is going all out with a splashy marketing plan that includes a museum-style exhibit in Manhattan demonstrating a dieter's experience before and after the addition of Alli.

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 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.

"They are about 20% fewer," he tells WebMD.

If Alli blocks fat so well, it may also block the absorption of important vitamins and minerals, critics allege.

"Any low-calorie diet should be accompanied by a multivitamin," Foster says. "The behavioral nuance here is that you don't want to take the vitamin at the same time as you take Alli." He recommends taking the vitamin at bedtime to avoid any depletion of its contents.

Some critics think it may be better to avoid taking the pill at all, saying it's not necessary.

"There are demonstrable short-term risks and no possibility of long-term benefit," points out Sidney Wolfe, MD, director of Public Citizen's Health Research Group in Washington, D.C.

If you really want to lose weight, he says the answer is not as sleek and sexy as taking a pill to augment your efforts. "You need to make a mild change in how much you eat and a mild change on how much you exercise, If you walk 2 miles more and eat 300 calories less per day, you will lose a pound a week or one-half a pound a week. It's slow but it works and has no risks."

Read the Fine Print

Despite its detractors, and even though it's not being billed as a magic bullet, many consumers may see it as one anyway.

"There are always going to be some people who won't read beyond the headlines, who so much want a miracle that they will believe this is one when its not," says Arthur Frank, MD, the medical director of the George Washington University Weight Management Program in Washington, DC.

If a person does choose to try Alli, they can't be passive about it, he says. "You really have to pay attention," Frank tells WebMD.

"There are drugs that you can use and be totally passive about, such as blood pressure or cholesterol medications, but you can't do that with Alli," he says.

"You have to be careless to use Alli incorrectly, but some people are careless," he says. Still, "if you are reasonably careful, it should be reasonably effective."

Published June 13, 2007.

SOURCES: Gary Foster, MD, director, Center of Obesity Research and Education, Temple University, Philadelphia. Valentine Burroughs, MD, MBA, chief medical officer and chairman of the department of medicine, North General Hospital, New York City. Arthur Frank, MD, medical director, George Washington University weight management program, Washington, D.C. George Blackburn, MD, PhD, director, Center for the Study of Nutrition Medicine, Beth Israel Deaconess Medical Center, Boston. Sidney Wolfe, MD, director, Public Citizen's Health Research Group, Washington, D.C.

© 2007 WebMD Inc. All rights reserved.


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