The effect of cyproheptadine on hunger, calorie intake and body weight in man.

The appetite stimulating action and the weight gaining potential of one month's treatment with the antihistamine and antiserotonergic compound cyproheptadine (Periactin) 4 mg three times daily was compared to placebo in a double-blind crossover trial in sixteen thin but otherwise normal volunteers who wanted to gain weight. Subjects gained significantly more weight on cyproheptadine than on placebo. There was also a corresponding relative increase in subjective hunger ratings and food intake during the period on active drug. Drowsiness was the most frequent side effect observed. These findings are discussed in relation to a possible serotonergic feeding mechanism.