Ginseng is found only in the Northern Hemisphere, in North America and in eastern Asia (mostly Korea, northern China (Manchuria), and eastern Siberia), typically in cooler climates. Panax vietnamensis, discovered in Vietnam, is the southernmost ginseng known. This article focuses on the Series Panax ginsengs, which are the adaptogenic herbs, principally Panax ginseng and P. quinquefolius. Ginseng is characterized by the presence of ginsenosides.

Siberian Ginseng (Eleutherococcus senticosus) is in the same family, but not genus, as true Ginseng. Like Ginseng, it is considered to be an adaptogenic herb. The active compounds in Siberian Ginseng are eleutherosides, not ginsenosides. Instead of a fleshy root, Siberian Ginseng has a woody root, (see below).

Both American ginseng (Panax quinquefolius) and Asian ginseng (Panax ginseng) roots are taken orally as adaptogens, aphrodisiacs, nourishing stimulants,^{[citation needed]} and in the treatment of type II diabetes, as well as for sexual dysfunction in men. The root is most often available in dried form, either whole or sliced. Ginseng leaf, although not as highly prized, is sometimes also used; as with the root, it is most often available in dried form.

This ingredient may also be found in some energy drinks, often the "tea" varieties; in these products, ginseng is usually present in subclinical doses and does not have measurable medicinal effects.^{[4][citation needed]} It can be found in cosmetic preparations as well, but has not been shown to have clinically effective results.