Ginseng is the root of plants in the genus Panax, including the species Korean ginseng (P. ginseng), South China ginseng (P. notoginseng), and American ginseng (P. quinquefolius). Ginseng has been used in traditional Chinese medicine for centuries as a tonic for patients with chronic illnesses. Many of the benefits of ginseng come from the presence of ginsenosides, a class of natural steroid glycosides and triterpene saponins. Ginseng also has immunomodulatory, neuroprotective, antioxidative, and antitumor properties.