Public Citizen says the drug may lead to a higher risk of aberrant crypt foci (ACF), which is believed to be a factor in colon cancer.
The group says data from the manufacturer of orlistat, Roche Pharmaceuticals, and recent studies show the drug causes ACF in rats.
HealthDay News reports that Public Citizen is concerned that the FDA will approve over-the-counter sales of the drug in the U.S.
Dr. Sidney Wolfe, director of Public Citizen's Health Research Group, says in a statement, "The failure to ban the prescription version of this drug or worse, to make it much more widely available by allowing OTC sales, is a decision that is likely to increase cancer incidence."
