Feature Archive

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.