ephedra

Ephedra is a genus of gymnosperm shrubs in the family Ephedraceae, comprising roughly 40 species native to arid and semi-arid regions of the Old and New Worlds, including parts of Asia, North America, and southern Europe. Plants are typically characterized by their photosynthetic, jointed green stems and small scale-like leaves; they are usually dioecious and can form dense stands in deserts and steppes.

Several Ephedra species produce alkaloids such as ephedrine and pseudoephedrine, though alkaloid content varies by species and environment. Historically, Ephedra sinica (ma huang) and related species were used in traditional Chinese medicine to treat bronchial asthma, congestion, and fever. In modern pharmacology, ephedrine and related compounds have stimulant and bronchodilator effects and have been used in decongestants and, in some contexts, weight-loss products; however, many Ephedra-derived preparations carry significant cardiovascular and neurologic risks.

Safety concerns led to regulatory actions in multiple jurisdictions. In the United States, the FDA prohibited the marketing of dietary supplements containing ephedra alkaloids in 2004 after safety reviews linked products to adverse events, including heart attack and stroke. Other countries have imposed restrictions or bans, while some Ephedra-containing medicines remain available under medical supervision. Given variability in alkaloid content, products derived from Ephedra are not interchangeable, and usage should follow medical and regulatory guidance.

Etymology, taxonomy, ecology, and conservation status vary by species, with some cultivated for ornamental use or traditional medicine and others remaining wild and rare.