Some of us wondered how Alli® would be received by the public when it became available as an over-the-counter product last June. Remember, Alli is a weaker form of Xenical®, which has been available on prescription for about 7 years. Xenical (the generic name is orlistat) works by blocking some of the fat consumed from being absorbed into the body. Apart from helping with weight reduction, this effect produces some unpleasant side effects: oily or fatty stools, an oily discharge, increased number of bowel movements, loss of control of bowel movements, and so on.

Alli is half-strength Xenical. So you may get: gas with oily spotting, loose stools, and more frequent stools that may be hard to control. But eating a low-fat diet lowers the chance of these bowel changes. You should limit fat intake in your meals to an average of 15 grams. In spite of this possibility, sales of the product (at $60 for a 90-pill package) have met GalxoSmithKline's expectations. The company predicts that 5-6 million people a year will use Alli. They claim that about 70% of users report losing weight, and seem to manage the side effects by restricting their fat intake. (Of course, this restriction of fat intake may be the secret of the weight loss!)