Chulling, Sumdo, Hoorling and Lira of Kinnaur district of Himachal Pradesh Distribution The genus is found worldwide, in desert regions, but not in Australia. Ecology Ephedraceae are adapted to extremely arid regions, growing often in high sunny habitats, and occur as high as 4000 m above sea level in both the Andes and the Himalayas. Drug and supplement uses The Ephedra alkaloids, ephedrine and pseudoephedrine constituents of E. sinica and other members of the genus have sympathomimetic and decongestant qualities, and have been used as dietary supplements, mainly for weight loss. The drug, ephedrine, is used to prevent low blood pressure during spinal anesthesia. In the United States, ephedra supplements were banned from the market in the early 21st century due to serious safety risks. Plants of the genus Ephedra, including E. sinica and others, were used in traditional medicine for treating headache and respiratory infections, but there is no scientific evidence they are effective or safe for these purposes. Ephedra has also had a role as a precursor in the clandestine manufacture of methamphetamine. Adverse effects Alkaloids obtained from the species of Ephedra used in herbal medicines, which are used to synthetically prepare pseudoephedrine and ephedrine, can cause cardiovascular events. These events have been associated with arrhythmias, palpitations, tachycardia and myocardial infarction. Caffeine consumption in combination with ephedrine has been reported to increase the risk of these cardiovascular events. Economic botany and alkaloid content The earliest uses of Ephedra species (mahuang) for specific illnesses date back to 5000 BC. Ephedrine and its isomers were isolated in 1881 from Ephedra distachya and characterized by the Japanese organic chemist Nagai Nagayoshi. His work to access Ephedra's active ingredients to isolate a pure pharmaceutical substance led to the systematic production of semi-synthetic derivatives thereof is relevant still today. Three species, Ephedra sinica, Ephedra vulgaris, and to a lesser extent Ephedra equisetina, are commercially grown in Mainland China as a source for natural ephedrines and isomers for use in pharmaceuticals. E. sinica and E. vulgaris usually carry six optically active phenylethylamines, mostly ephedrine and pseudoephedrine with minor amounts of norephedrine, norpseudoephedrine as well as the three methylated analogs. Reliable information on the total alkaloid content of the crude drug is difficult to obtain. Based on HPLC analyses in industrial settings, the concentrations of total alkaloids in dried Herba Ephedra ranged between 1 and 4%, and in some cases up to 6%. For a