Are Fat Blockers Safe?

In 2010, the Food and Drug Administration (FDA) mandated a warning label associated with rare liver injury and liver failure in patients using orlistat (trade names, Xenical and Alli), a fat-blocker.

Function

According to WebMD, orlistat works by blocking 30 percent of the fat a patient eats from being absorbed in the body. This fat-blocker is the only one currently approved for long-term use for the treatment of obesity, but its effectiveness has not been established beyond two years.

FDA Review

Twenty-six cases of liver injury and six cases of liver failure in patients using orlistat were reported to the FDA between 1999 to October 2008, according to the FDA. The most common complaints included abdominal pain, jaundice (yellowing of the skin or whites of the eyes) and weakness.

Side Effects

According the Mayo Clinic, changes in bowel movements in patients using the drug are common. Bowel changes such as gas with an oily anal discharge, more frequent bowel movements, hard-to-control bowel movements, loose stools and diarrhea have been reported. WebMD states these side effects are mild and temporary.

References

• WebMD: Prescription Weight Loss Drugs
• FDA: FDA Drug Safety Communication: Completed safety review of Xenical/Alli (orlistat) and severe liver injury
• WebMD: Prescription Weight Loss Drugs
• Mayo Clinic: Alli weight-loss pill: Does it work?

Resources

• WebMD: Drugs & Medications - Xenical Oral