Traditional Chinese Medicine tells us that American Ginseng promotes YIN energy, cleans excess yang and calms the body. The reason it has been claimed that American ginseng promotes yin (shadow, cold, negative, female) while Asian Ginseng (notable Korean) promotes YANG (sunshine, hot, positive, male) is that, according to TCM, things living in cold places or northern side of mountains or southern side of rivers are strong in yang and the converse, so the two are balanced
The natural color of the ginseng root is white. When it is simply cleaned and dried, it retains it natural color. Red ginseng, on the other hand, is the result of being steamed with a solution of herbs. Steaming greatly enhances Ginsengs quality.
Which is best for you really depends on what you need. Chinese Ginseng is good for a tonic to build the body - like putting gasoline in the car. Korean Red Ginseng is like burning straight nitro. American Ginseng is prized because it drives like nitro (close but still second) without the worry of blowing your engine plus still strengthening your body for endurance like Chinese Ginseng but much stronger.
"Since American ginseng has a lower ratio of Rg1/Rb1, it seems to calm the CNS. In contrast, Asian ginseng appears to stimulate the CNS."