The last word on the subject (Source: Mayo Clinic)
Note : On February 6th, 2004 The Food and Drug Administration (FDA) issued a final rule prohibiting the sale of dietary supplements containing ephedrine alkaloids (ephedra) because such supplements present an unreasonable risk of illness or injury. The rule became effective 60 days from the date of publication.
On April 14, 2005 a Federal District Court in Utah under Judge Tena Campbell struck down a U.S. Food and Drug Administration ban on ephedra. The ruling is specific only to Utah, although it calls into question the FDA ban in general. The suit in question was brought by the dietary supplement manufacturing company Nutraceutical Corporation. The decision specifically questioned the ability of the FDA to ban ephedra completely without conclusively demonstrating danger at low doses .
Although most evidence around the risks associated with ephedra use is based on higher doses or combination use with caffeine, a universal ban was implemented by the FDA, as it would be unethical to conduct human studies of lower doses in order to establish safety. Therefore, Judge Campbell felt there is inadequate safety data at lower doses. This places the FDA in a bind under current dietary supplement regulatory law - it suspects dangers at low doses, but cannot seek to prove these dangers .
It remains unclear whether ephedra will find its way back onto shelves, despite widespread acknowledgement of significant safety risks, including serious potential cardiovascular events or death .
Ephedra sinica , a species of ephedra (Ma huang), contains the alkaloids ephedrine and pseudoephedrine, which have been found to induce central nervous system stimulation, bronchodilation, and vasoconstriction. In combination with caffeine, ephedrine appears to elicit weight loss (in trials of 1-12 months duration). However, studies of ephedra or ephedrine monotherapy have been equivocal. The majority of human trials of weight loss have been small with methodological weaknesses including large dropout rates due to adverse effects, and incomplete reporting of blinding or randomization. Numerous trials have documented the efficacy of ephedrine in the management of asthmatic bronchoconstriction and hypotension. However, commercial preparations of non-prescription supplements containing ephedra have not been systematically studied for these indications.
Major safety concerns have been associated with ephedra or ephedrine use, including hypertension, tachycardia, CNS excitation, arrhythmia, myocardial infarction, and stroke. In 1997, due to over 800 U.S. reports of serious toxicity (and many more worldwide) including at least 22 deaths in adolescents and young adults, the U.S. Food and Drug Administration (FDA) adopted a policy that ephedra-containing products must: (1) be labeled with all possible adverse effects, including death; (2) contain no more than 8mg of ephedrine per serving; and (3) be used for no more than seven days. The FDA also proposed a maximum daily dose of 24mg, and a ban on ephedra-caffeine combination products (these proposed limits were subsequently withdrawn).
In 2002, Samenuk et al. identified 926 cases of possible ephedra toxicity reported to the Adverse Reaction Monitoring System of the FDA between 1995-1997. In 37 patients, use of ephedra was temporally related to stroke (16 patients), myocardial infarction (10), or sudden death (11). Autopsies performed in patients who experienced sudden death showed a normal heart in one, coronary atherosclerosis in three, and cardiomyopathies in three. In 36 of the 37 patients, use of ephedra was reported to be within the manufacturers' dosing guidelines.
In 2003, a report was prepared by Shekelle et al. on behalf of the RAND Southern California Evidence-based Practice Center for the Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services. This study reviewed available clinical trials, as well as more than 1,500 adverse event reports to the FDA and adverse event reports to the manufacturer Metabolife. Although most prospective trials were not sufficiently large and most adverse event reports were not sufficiently detailed, the authors identified three deaths, two myocardial infarctions, two cerebrovascular accidents, one seizure, and three psychiatric cases that were considered to be "sentinel events" (i.e., strongly tied to ephedra use within 24 hours without other plausible explanations). In addition, 50 other possible sentinel events were identified.
A 2003 analysis by Bent et al. in Annals of Internal Medicine found that products containing ephedra account for 64% of all adverse reactions to herbs in the United States, but only represent 0.82% of herbal product sales. The relative risk for an adverse reaction in a person using ephedra compared with other herbs was extremely high, ranging from 100 (95% CI, 83 to 140) for kava to 720 (95% CI, 520 to 1100) for Ginkgo biloba . It was concluded that ephedra use poses a greatly increased risk of adverse reactions compared with other herbs. A 2003 analysis published in Neurology also found increased risk of stroke associated with ephedra-containing products.
Despite widely publicized safety concerns and the highly publicized 2003 death of a U.S. major league baseball pitcher thought to be related to ephedra, prior to the ban on ephedra, 14% of individuals using non-prescription weight-loss products in the U.S. continued to take ephedra or ephedrine-containing products.