Part used: mostly the root, sometime the leaves.
Herbal action: adaptogen, nervine, tonic, aphrodisiac.
History: Ginseng has an extensive written and traditional history, primarily because of its fame in the Orient for extending lifespan.
Since the various ginsengs have different properties, there is inconsistency in the results of the various ginseng studies. Lewis provides a good overview of this concern. Further problems are associated with studies which do not identify species or type of plant; nomenclature of constituents, extraction technique, purification, dosage, or even the animal species used in studies. The ginsengs do work differently in different animals. Ginseng is considered a panacea due to it broad spectrum use and its long history. Even though it is a great Qi tonic, it is not considered a perfect herb.
While many of the physiological properties of the ginsengs undoubtedly have to do with other factors, the main components are the saponin groups Rg1 and Rb1. These two factors are diametrically opposed to each other. This means the ratio of these two factors means a lot when it comes to herbal function. The popular ginsengs contain both factors, but the Asian Ginseng contains much higher amounts of Rg1 than the American Ginseng does, while there is more Rb1 in the American Ginseng. This ratio is the significant distinction between how the two work.