A double-blind clinical evaluation of the anorectic activity of phenylpropanolamine versus placebo.

A double-blind, placebo-controlled 14-week study evaluated the anorectic activity of 75 mg of phenylpropanolamine HCl (PPA) in 102 overweight subjects. Changes in weight and vital signs were monitored at two-week intervals. Eighty-five subjects, 90% of the PPA group and 83% of the placebo group, completed the study. The PPA group consistently showed significantly greater weight loss than the placebo group after 6, 8, 10, 12, and 14 weeks of the study. The only significant change in vital signs was a rise in diastolic blood pressure noted at week 12 in the PPA group, but this change was small (3.43 mmHg) and considered clinically insignificant. Overall, 75 mg of PPA was associated with significant weight loss as early as week 6 of the study and was shown to be a superior anorexiant in comparison with placebo.