OBJECTIVE: To examine in overweight humans the short-term safety and efficacy for weight loss of an herbal supplement containing Ma Huang, Guarana and other ingredients. DESIGN: An 8 week randomized, double-blind placebo controlled study of a herbal dietary supplement (72 mg/day ephedrine alkaloids and 240 mg/day caffeine). SUBJECTS: Overweight men and women (body mass index,  29 and £35 kg/m2). MEASUREMENTS: The primary outcome variable was body weight change. Secondary variables included anthropometric, metabolic and cardiovascular changes. RESULTS: Sixty-seven subjects were randomized to either placebo (n=32) or active Ma Huang/Guarana (n=35). Twenty-four subjects in each group completed the study. Active treatment produced significantly (P<0.006) greater loss of weight (X±s.d.,-4.0±3.4 kg) and fat (-2.1±3.0% fat) over the 8-week treatment period than did placebo (-0.8±2.4 kg and 0.2±2.3% fat). Active treatment also produced greater reductions in hip circumference and serum triglyceride levels. Eight of the 35 actively treated subjects (23%) and none of the 32 placebo-treated control subjects withdrew from the protocol because of potential treatment-related effects. Dry mouth, insomnia and headache were the adverse symptoms reported most frequently by the herbal vs placebo group at the final evaluation visit. CONCLUSIONS: This herbal mixture of Ma Huang and Guarana effectively promoted short-term weight and fat loss. Safety with long-term use requires further investigation. International Journal of Obesity (2001) 25, 316-324 | 
