Hemodynamic impact of an ephedra-free multicomponent weight-loss supplement.

PURPOSE: The effect of Metabolife Ephedra-Free on blood pressure (BP) and hemodynamics was studied. METHODS: Healthy volunteers were randomly assigned to take a single dose of Metabolife Ephedra-Free or matching placebo and then crossed over to the opposite treatment after a seven-day washout period. BP was measured at baseline and one, three, and five hours after administration. Cardiac index, systemic vascular resistance index (SVRI), and total thoracic fluid content were determined in a subgroup of subjects. RESULTS: Twenty patients (mean +/- S.D. age, 24.8 +/- 1.9 years) completed the study. No significant differences in systolic or diastolic BP were found between the Metabolife Ephedra-Free and placebo groups. In the subgroup (n = 8), SVRI was higher (but not significantly so) in the Metabolife Ephedra-Free group than in the placebo group at one hour (2162.5 +/- 421.1 versus 1934.6 +/- 344.2 dyn x sec x cm(-5) x m(2)); the difference was significant at five hours (1981.6 +/- 293.3 versus 1765.1 +/- 340.3 dyn x sec x cm(-5) x m(2)). CONCLUSION: Single doses of Metabolife Ephedra-Free did not affect BP in healthy young volunteers. SVRI did not exceed the normal range but was elevated at five hours compared with SVRI in placebo recipients.

Electrocardiographic effects of an Ephedra-Free, multicomponent weight-loss supplement in healthy volunteers.

STUDY OBJECTIVE: Metabolife 356, an ephedra-containing weight-loss product, substantially increases the corrected QT (QTc) interval. Metabolife Ephedra Free, a similar supplement, contains caffeine and extracts of green tea, garcinia cambogia, and yerba mate. Its electrocardiographic (ECG) effects are not known. Therefore, we sought to determine the effect of this supplement on the QTc interval. DESIGN: Randomized, double-blind, placebo-controlled, crossover study. SETTING: University of Connecticut, Storrs Campus. SUBJECTS: Twenty healthy volunteers. Intervention. A single capsule containing half the normal recommended dose of Metabolife Ephedra Free or matching placebo was administered in crossover fashion, with a 7-day washout period between treatments. MEASUREMENTS AND MAIN RESULTS: Baseline and three postdose ECG measurements were obtained, and QTc intervals were measured over a 5-hour study period. No significant differences in the QTc interval or other ECG variables were observed between the Metabolife Ephedra Free and placebo groups. CONCLUSION: At half the recommended single dose, Metabolife Ephedra Free does not affect the QTc interval or other ECG variables over 5 hours. Dose-response studies and studies of longer duration should be conducted.