Ephedra

Ephedra, also known as Ma-huang, is a species of plant used in Chinese medicine for respiratory complaints. It is the source of ephedrine, a purified compound. Dietary supplements for weight loss might have either the plant source or the purified compound. Ephedra is frequently combined with other natural products, such as caffeine, to increase the effects.

Mechanism of Action: Sympathomimetic

• Increases thermogenesis (fat burning); decreases appetite

• Bronchodilates, hence use in respiratory problems

• But, has the unwanted effects of increasing BP and increasing HR

Ephedra has been linked to cardiovascular events and death. After an exhaustive analysis, the FDA banned the sales of Ephedra in the U.S. in April 2004. Low dose Ephedra products are still available over the web. I have also seen them in gas stations, packaged in single doses.

Recent Evidence

• Dose used in the study: Low dose Ephedra (24mg) + caffeine (70mg) three times per day. Study length was 12 weeks.

• Ephedra + caffeine increased the resting metabolic rate more than placebo

• Ephedra + caffeine produced wt loss of 3.5 kg +/- 0.6kg compared to only 0.8 kg +/- 0.5kg in the placebo group (p < 0.02).

• No adverse effects were reported in this study, which is similar to other randomized controlled trials.

Reference

• Greenway et al. Obes Res. 2004 Jul;12(7):1152-7

How Might You Interpret This Research

• In a highly-controlled setting, Ephedra is both safe and modestly effective (7.7 pound weight loss in 3 months = 5% wt loss for someone weighing 150lbs). In an uncontrolled setting, Ephedra's risk for serious adverse events outweighs these modest effects.