Also known as yellow river, General of Respiration and Mormon Tea. Ma Huang is a Chinese herb whose active ingredient is ephedra (ephidrene). In recent years there have been many concerns surrounding the use of Ma Huang. However, when taken according to prescribed instructions and warnings, Ma Huang is a safe natural product. The dietary supplement industry has been working with the FDA to set dosage limitation and standard warnings for all ephedra-containing products. If you use ephedra products, please read the label directions and warnings prior to use. Not intended for use by persons under 18 years of age.