Xenadrine RFA-1 contains Ephedra , which has been linked to dangerous side effects. According to a study commissioned by the Food and Drug Administration (FDA), Ephedra may seriously harm and can potentially kill some who use it. The research adds to the long-standing controversy about the dietary supplement, which is also marketed as an energy booster and treatment for respiratory illness.

Ephedra is derived from an Asiatic shrub and contains ephedrine. Ephedrine is a stimulant that acts on the central nervous system to relax bronchial tubes. Products containing Ephedra can produce the following adverse reactions: heart attack, stroke, tachycardia, paranoid psychosis, depression, convulsions, coma, fever, vomiting, palpitations, hypertension, and respiratory depression.

"The use of dietary supplements does pose a health risk to some people," says Neal Benowitz, MD, professor of medicine and chief of clinical pharmacology at the University of California, San Francisco. "Just because it's natural, doesn't mean it's safe." Benowitz and postdoctoral researcher Christine Haller, MD, reviewed the 140 reports of deaths or injuries the FDA received related to Ephedra. Researchers concluded that ephedrine use "definitely" or "probably" caused harm in 31 percent of the cases. Of these cases, three people died, seven suffered permanent injury and four required ongoing medical treatment.

However, the FDA does not currently regulate many products containing ephedra because it is labeled as a dietary supplement and thus is protected under the Dietary Supplement Health & Education Act of 1994. Pursuant to the Act, the FDA cannot regulate dietary supplements such as Ephedra unless it has been proven to be unsafe. Drug companies have taken advantage of the current status of ephedrine and have attempted to produce a product with amphetamine-like qualities by mixing ephedrine with other stimulants, such as caffeine.

NOTE: This information does not pertain to Xenadrine-EFX, which is an ephedra-free product.