In scientific studies, it was found the medicinal effects of ginseng, no matter American or Asian, are due to the family of chemicals called ginsenosides. Both American and Asian ginsengs contain lots of different ginsenosides. Ginsenoside Rf can only be found in Asian ginseng but not in the American variety; whereas, it is reported that ginsenoside ratios Rg1/Rf and Rc/Rb2 are higher in American ginseng than in Asian varieties. The chemical variations may be one explanation why different medicinal effects are observed between American and Asian ginsengs. However, this is still under scientific investigation.