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Panax quinquefolius, commonly known as American Ginseng and often by its Chinese name Xiyangshen (simplified Chinese: 西洋参; traditional Chinese: 西洋參; pinyin: xīyángshēn), is an herbaceous perennial in the ivy family that is commonly used in medicine. It is native to eastern North America, though it also cultivated beyond its range in places such as China.
The plant’s forked root and leaves were traditionally used for medicinal purposes by Native Americans. Since the 1800s, the roots have been collected by “'sang hunters,” and sold to Chinese or Hong Kong traders, who often pay very high prices for particularly old wild roots.
American Ginseng was formerly particularly widespread in the Appalachian region (and adjacent forested regions such as Pennsylvania and New York State), but due its popularity the wild plant has been overharvested, and is thus rare in most parts of the United States. It is also grown commercially, under artificial shade, in fields in Wisconsin and Minnesota, and usually harvested after three to four years when ripe.
Like Panax ginseng, American ginseng contains dammarane type ginsenosides as the major biologically active constituents. Dammarane type ginsenosides includes 2 classifications: the 20(S)-protopanaxadiol [ppd] and 20(S)-protopanaxatriol [ppt] classifications. American ginseng contains high levels of Rb1, Rd (ppd classification) and Re (ppt classification) ginsenosides – higher than that of P. ginseng in one study. 
When taken orally, ppd-type ginsenosides are mostly metabolized by intestinal bacteria (anaerobes) to ppd monoglucoside, 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (M1).  In humans, M1 is detected in plasma from 7 hours after the intake of ppd-type ginsenosides and in urine from 12 hours after the intake. These findings indicate that M1 is the final metabolite of ppd-type ginsenosides. 
M1 is referred to in some articles as IH-901  , and in others as compound-K.