d-Fenfluramine (dF) (15 mg twice daily) has been studied in controlled trials in human obesity and has been shown to increase adherence to diet, to enhance its efficacy, and most importantly, to prevent weight regain when continued over 1 y. Few side effects, mostly transient, have been observed. A long-term use of dF in the management of some obese patients could be foreseen. Additionally, evidence that dF improves eating symptoms and dysphoric impairments in obese cravers, premenstrual syndrome, seasonal affective disorder, and smoking withdrawal syndrome has been presented.