With more than 90 million Americans affected by obesity, developing medications to help combat weight gain and its associated diseases has become a priority. In a study using obese mice, a team led by Namandjé Bumpus of Johns Hopkins University recently showed that a commonly prescribed epilepsy drug, valproic acid, reduced fat accumulation in the liver and lowered elevated blood sugar levels like those associated with type 2 diabetes. Body weight also stabilized in mice given the drug, whereas untreated mice continued to gain weight. Additional experiments in mouse and human liver cells suggested that the byproducts of valproic acid produced as the body breaks down the drug, rather than valproic acid itself, were responsible for the observed effects. These byproducts achieved the same effects in cells at one-fortieth the concentration of valproic acid, making them promising candidates for further drug development.