Ephedra is a shrub that grows in many countries throughout the world. Ma Huang is a popular species of Ephedra found in Asia. It contains an alkaloid called ephedrine which is similar to our body's natural adrenaline.
Ephedrine is found in many over-the-counter cold, allergy, and asthma medications. Ephedra is also used by some people as a weight loss agent. It is said to suppress appetite and to increase the metabolic rate of adipose (or fatty) tissue. (Metabolism 1986; 35, 260; Am J Clin Nutr 1992; 55, 246S). Ephedra has also been promoted as a substance that can give you more energy and has been included in a variety of bodybuilding supplements.
Unfortunately, ephedra is a very dangerous substance medically. Common side effects associated with the use of ephedra include increase in blood pressure and heart rate, insomnia, anxiety, and disturbances in heart rhythm. These side effects may be more common in patients who are taking medications, such as, beta-blockers, theophylline, antidepressant drugs, and nasal decongestants and in individuals who are being treated for high blood pressure, depression, anxiety, heart disease, thyroid disorders, diabetes, or prostate enlargement. Episodes of congestive heart failure, stroke and heart attack have been reported in otherwise healthy people who took ephedra (N Engl J Med 2000; 343:1833; Mayo Clin Proc 2002; 77:12).