When people say "ephedra," they usually mean the Chinese variety ma huang (E. sinica). Ma huang increases metabolic rate, the speed the body burns calories. It also depresses appetite a bit. This combination of effects led to studies of the herb (actually chemically isolated ephedrine) for weight control, usually in combination with another stimulant, caffeine.
In physician-supervised weight-loss programs that include a low-fat diet and regular exercise, treatment with a combination of ephedrine and caffeine has increased weight loss by about 5 percent. In other words, a person who loses 100 pounds without ma huang might lose 105 with it.
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In a 3-month trial, Danish researchers showed that compared with overweight women taking medically inactive placebos, those taking oral ephedrine (20 milligrams three times a day) lost somewhat more weight. And in a 2-month study, Italian researchers found that overweight women lost more weight if they supplemented a low-calorie diet with oral ephedrine (50 milligrams three times a day).
To experience ephedra's weight-reduction benefits, you must be clinically obese, that is, at least 20 percent heavier than your recommended weight. Ephedrine has shown no benefit in people who want to lose 5 to 10 pounds.
When used for weight control, ephedra typically causes side effects that may be unpleasant. Ephedra may raise blood pressure and cause jitters, irritability, and insomnia. People with high blood pressure, heart or kidney disease, or a history of stroke should not use it. In very large doses, ephedra may cause potentially fatal heart problems. Coffee and other herbs containing caffeine increase ephedra's effects and side effects. Ephedra and coffee should be used for weight control only under medical supervision.
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Experts generally agree that the keys to permanent weight loss are a low-fat, low-calorie diet and daily exercise. Nonetheless, ephedra is an ingredient in many herbal weight-loss formulas sold in health food stores and drugstores.