Ma Huang is a herbal remedy used in traditional Chinese medicine for over 5,000 years fr the treatment of asthma, hav fever and the common cold. It comes from the plat Ephedra sinica and has been marketed in the United States and other countries as the diet supplement ephedra.

Ephedra constricts blood vessels and increases blood pressure and heart rate. There are also several other species that belong to the genus Ephedra which have been used for medicinal purposes. Both Native Americans and Mormon pioneers drank a tea brewed from an ephedra species often referred to as Mormon tea. This specie, however, lacks the alkaloids found in Ephreda sinica.

Dietary supplements containing ephedra were banned by the US Food and Drug Administration in 2004 due to reports of adverse effects and deaths. This ban was upheld by an appeal court in 2006.