The publication of the ﬁrst edition of the Handbook of Obesity occurred just as the Food and Drug Administration requested the recall of fenﬂuramine and dexfenﬂuramine. Each drug alone and in combination with phentermine had been associated with a rash of valvular heart disease. These cases were similar to some seen with the carcinoid syndrome that secretes serotonin. There was an accumulation of material on the aortic valves in the heart that made them leaky. The good news is that many of these valvular lesions have been reversible when the drugs were discontinued, and there are no cases known to us of progression after the drugs were stopped.