Objective: To evaluate the efficacy and side effects of an herbal formulation to promote weight loss, as compared to placebo.
Design: 12-week multicenter double-blind, placebo-controlled, randomized parallel groups design. Study conducted at three clinical sites in New York State. Subjects were randomized to receive either the 'active' product or a 'placebo' supplement for 12 weeks. Minimal steps were taken to influence lifestyle changes with regard to diet or exercise.
Subjects: 102 overweight/obese (30<BMI</=39.9 kg/m(2)) volunteers between the ages of 18 and 65 y.
Main outcome measures: Weight, percent body fat, fat mass, waist circumference, BMI, blood pressure, and pulse measured at 2 days, 1 week, 2 weeks, 4 weeks, 8 weeks, and 12 weeks postrandomization.
Results: Subjects receiving the 'active' treatment experienced, on average, an additional 1.5 kg of weight loss compared with subjects receiving the placebo. In addition, subjects receiving the 'active' treatment experienced greater reductions in BMI and waist circumference over the 12-week period. No differences were observed with respect to percent body fat, fat mass, diastolic or systolic blood pressure, pulse, the occurrence of any adverse event, or the occurrence of any presumed treatment-related adverse event. Testing of the study product by two independent laboratories indicated that it had only approximately half of the intended amount of ephedrine alkaloids and caffeine.
Conclusions: Over the 12-week trial, subjects on the active treatment experienced significantly greater weight loss than subjects on placebo, without an increase in blood pressure, pulse, or the rate of adverse events. These benefits were achieved in the absence of any lifestyle treatment to change dietary or exercise behavior and with lower doses of ephedrine alkaloids and caffeine than those commonly utilized.