Panax ginseng (also known as Korean, Asian, or Chinese ginseng) is a perennial, deciduous plant, reaching roughly 50 centimeters in height, native to wooded areas of Korea, China, Nepal, and Manchuria. A close relative of American ginseng (Panax quinquefolium), and more distantly related to Siberian ginseng (Eleutherococcus senticosus), Korean ginseng has dark green, compound leaves, which consist of five serrate, oval-shaped leaflets. The plant flowers from June through August, bearing a single cluster of greenish yellow flowers, which eventually produce small, bright-red berries. The fleshy, forked root of the plant, which is usually harvested at 10 to 15 centimeters in length but may be as long as 50 centimeters in older plants, is used for health purposes.
Throughout much of Asia, especially China, Korea, and Japan, ginseng has been used for centuries as a tonic or cure-all. In fact, the genus name, Panax, comes from the Greek word for panacea. Chinese medical literature from the first century A.D. states that ginseng was used for "quieting the spirit, curbing the emotion, stopping agitation, removing noxious influences, brightening the eyes, enlightening the mind, and increasing wisdom.
The primary active compounds in ginseng are a group of triterpenoid saponins known as ginsenosides. Korean ginseng contains thirteen known ginsenosides, along with other constituents such as panaxans and polysaccharides.
Modern herbalists recommend ginseng as an adaptogen, a general tonic to aid in adapting to physical and psychological stressors. In studies conducted on mice, ginseng improved adaptation to fatigue, heat stress, and electroshock stress. Germany's Commission E has approved ginseng root for use as a "tonic for invigoration and fortification at times of fatigue and debility, for declining capacity for work and concentration, also during convalescence." Studies suggest ginseng may promote cardiovascular health by inhibiting platelet aggregation and improving cholesterol ratios. Research also indicates that compounds found in ginseng root can promote immune system function by stimulating natural killer cell activity.
Commission E approves a dosage of 1 to 2 grams per day of dried root, or preparations providing the equivalent, and reports no known side effects at this dosage range. However, some herbalists do not recommend its use during pregnancy or lactation, and urge women of menstruating age to use the herb with caution. Research indicates that ginseng has no toxic effect with long-term use.