What Is Xenical, How Does It Work, And How Effective Is It In Reducing Weight?

Question: What is Xenical, how does it work, and how effective is it in reducing weight?

Answer: Xenical is the brand name for the product orlistat, which is a fat blocker. And until recently it was available only by prescription. What it does is it blocks about 30 percent of the fat calories in the diet, it prevents about 30 percent of the fat from being absorbed, so it passes through the system undigested. And it can be modestly helpful as an aid to weight loss.

When combined with a healthy eating plan and a program of regular exercise, people might lose a few extra pounds. Three to five pounds perhaps if they're using Xenical than if they're not. And they may have more success in keeping the weight off longer term.

So the benefits may be medicially significant but they don't tend to be profound.

Use of the drug may be limited by side effects which can include gastrointestinal distress of various kinds, so it's not for everybody. This product is now available in an over-the-counter form -- little less potency, but same drug, called Alli.