Not all individuals who have epilepsy respond to traditional treatments. Strict adherence to a ketogenic diet high in fats and extremely low in carbohydrates is sometimes used to treat these patients. A new study shows that intranasal delivery of leptin, a hormone important in feeding and energy metabolism, delays the onset of convulsions in rodents, leading to the suggestion that leptin-triggered signaling may be a key to how a ketogenic diet combats epilepsy.