Use of drugs for the treatment of obesity is regarded more skeptically than drug use in other chronic disease; this view, however, may be inappropriate. Anorexiant drugs, the major class of drugs currently available for treating obesity, differ in several important ways, including whether they act on noradrenergic or serotonergic systems and in their potential for abuse. New approaches to drug treatment of obesity include thermogenic agents and drugs acting on the digestive system and hormones.