From the Manufacturer:
American Ginseng is similar to its Asian cousin, Korean Ginseng. Both varieties are considered true Panax Ginseng types. It was introduced to early American settlers by Native Americans and soon became a major export commodity to the Far East.
NOW American Ginseng is derived from 4 to 5 year-old high quality cultivated Wisconsin ginseng roots and are especially high in ginsenosides (5% minimum), the active measurable components in ginseng.