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An acute clinical trial evaluating the cardiovascular effects of an herbal ephedra–caffeine weight loss product in healthy overweight adults


Objective: This study was undertaken to determine the acute effects of a commercial weight loss supplement containing herbal ephedrine and caffeine on cardiovascular function in healthy overweight adults.

Design: Randomized double blind clinical trial evaluating the cardiovascular effects of an ephedra–caffeine (XenadrineTM; XEN) based herbal product vs placebo (PLA).

Subjects: Twenty-seven healthy overweight adults (age 21–60 y; body mass index ≥25 kg/m2).

Measurements: Systolic and diastolic blood pressure, heart rate, serial electrocardiograms (EKG) and Doppler echocardiograms.

Results: A comparison of means between the groups indicated no statistically significant differences at the start of the study for the variables above. There were no serious adverse events. When examining the effects of XEN vs PLA on cardiovascular health/function, there were no significant effects observed in heart rate, systolic blood pressure, diastolic blood pressure, left ventricular ejection fraction, heart valve function or in cardiovascular physiology within the parameters measured.

Conclusion: These findings indicate that, over a 14-day period, ingestion of the commercial weight loss supplement in a healthy overweight population did not produce any noticeable cardiovascular side effects.

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Funding for this study was provided by Cytodyne Technologies.

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Correspondence to D Kalman.

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Kalman, D., Incledon, T., Gaunaurd, I. et al. An acute clinical trial evaluating the cardiovascular effects of an herbal ephedra–caffeine weight loss product in healthy overweight adults. Int J Obes 26, 1363–1366 (2002).

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  • caffeine
  • cardiovascular
  • ephedrine
  • sympathomimetic
  • weight loss

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