Orlistat (marketed as Xenical) is a drug designed to treat obesity. It works by inhibiting pancreatic lipase, an enzyme that breaks down fat in the intestine. Without this enzyme, fat from the diet is excreted undigested, and not absorbed by the body.

It is available only on prescription, although, as with many prescription drugs, it is possible to obtain it from online pharmacies.

It has a number of side effects related to digestion. Because its main effect is to prevent dietary fat from being absorbed from the gut, the fat is excreted and so the stool becomes oily, runny, and gassy. Bowel movements may become frequent, urgent or uncontrollable. Obviously many patients find this uncomfortable.

Because some vitamins are fat soluble, the effect of Xenical (Orlistat) is to reduce their body adsorption. Therefore the drug should only be taken in conjuction with fatty meals, and a multivitamin tablet containing these vitamins (D E K and beta-carotene) should be taken once a day, at least 2 hours before or after taking the drug.

In the March 15, 2004 issue of Cancer Research,[1] Steven J. Kridel et al. state that orlistat may also inhibit growth of prostate cancer, and in theory may be useful in treating other cancers, by interfering with the metabolism of fats.

You must not take Xenical if you:

• have problems absorbing food
• have reduced gallbladder function
• are pregnant, or are still breast-feeding (it is not known whether Xenical is expressed in breast milk)
• have certain kidney problems (consult your doctor).

External links

• Xenical / Orlistat Fact Sheet
• FDA Consumer Info