Ma Huang (Ephedra sinica) has a long history of use in traditional Chinese medicine, primarily as a bronchodilator and stimulant. The plant contains ephedrine alkaloids, which are well-documented sympathomimetic compounds. Ephedrine acts directly on adrenergic receptors and indirectly by increasing the release of endogenous catecholamines, including epinephrine (adrenaline) and norepinephrine, from nerve endings. This dual action results in stimulation of the central nervous system, increased heart rate, bronchodilation, and elevated blood pressure—all effects mediated by the epinephrine (adrenergic) body system.

Scientific validation is strong regarding ephedrine's pharmacological effects on adrenergic pathways. Numerous studies from the 20th century, as well as regulatory and pharmacological reviews, confirm that ephedrine increases circulating levels of catecholamines, mimicking the physiological effects of epinephrine. Because of these effects, Ma Huang and its alkaloids were once widely used in over-the-counter decongestants, asthma medications, and weight loss supplements.

However, due to safety concerns—including reports of hypertension, cardiovascular events, and even death—the use of ephedrine-containing products is now heavily regulated or banned in many countries. Despite safety concerns, the mechanism by which Ma Huang supports the epinephrine (adrenergic) system is scientifically substantiated.