The Journal of Alternative and Complementary Medicine

Objective: To determine if an herbal dietary supplement for weight loss increases metabolism.

Design: Measurement of peak oxygen consumption in response to the supplement followed by a double-blind placebo-controlled crossover measurement of oxygen consumption in response to the supplement.

Setting: The study was conducted in an academic research clinic.

Subjects: Ten obese females (aged 41 ± 4 years [body mass index (BMI) 33.3 ± 2.6 kg/m²) participated in the peak oxygen consumption test; six of these females participated in the crossover trial.

Interventions and Outcome Measures: Peak oxygen consumption was measured for 45 minutes after taking two herbal dietary supplement capsules orally, each containing the equivalent of 10 mg of caffeine and 5 mg of ephedrine. The crossover trial measured oxygen consumption for 45 minutes after taking two herbal dietary supplement capsules or two placebo capsules orally.

Results: The herbal dietary supplement increased peak oxygen consumption 0.178 ± 0.03 (SEM) kcal/min (8.01 ± 1.35 kcal/min expressed over 45 minutes) above baseline (p < 0.0001), and 2.0 ± 0.56 kcal/min over 45 minutes compared to placebo (p < 0.006).

Conclusions: The herbal dietary supplement increased oxygen consumption when taken according to the package directions. The significance of this rise for weight loss requires further research.