Ephedrine is a medication and stimulant that is primarily used to treat asthma, bronchitis, and other respiratory conditions by opening up the airways. It works by stimulating the sympathetic nervous system, which can increase heart rate and blood pressure. Ephedrine is also sometimes used in emergency situations to treat low blood pressure. In addition to its medical uses, ephedrine has been associated with weight loss and athletic performance enhancement, leading to its inclusion in some dietary supplements. However, due to potential side effects and health risks, its use in these contexts is often regulated or banned in many countries.