Ginseng
First, what plant are we talking about? There are 11 plants called ginseng, including "Siberian Ginseng", which is called ginseng only for marketing(though it also is an adaptogen). Panax quinquefolium is the plant under discussion. Panax, the generic name, is derived from the Greek Panakos (a panacea). Often called Asian, red, or white ginseng. The highest quality 'Asian' ginseng, on the market, is grown in Wisconsin, and Kentucky, USA. 'Red' refers to ginseng that has been preserved by steam cooking and 'white' refers to ginseng that has been air dried. Despite all the marketing nonesense, the plant grows throughout the world. I harvest wild Panax quinquefolium, whenever I am in Emmental, Switzerland. If I don't find ginseng, at least I come home with great cheese !
Among the major types of ginseng, there are various grades of quality. For example, wild ginseng is considered more potent than commercially grown ginseng. The potency is also related to the quality of soil in which it was grown, the duration of its growth, the climate in which it was grown, and the methods by which it was harvested and processed.
Panax quinquefolium has astonishing neurological effects and is particularly adroit at stopping the overproduction of cortisol, which, in my opinion, is its most valuable quality. As such, Panax quinquefolium is an adaptogen - a compound that helps the body to adapt to physical and and psychological stressors. It does this by heightening the productivity of the adrenal glands.
As mentioned previously, adrenaline and cortisol are both exitatory hormones, but cortisol has longer lasting effects. Because cortisol stays in the system longer than adrenaline, it is more disruptive than adrenaline.
Panax quinquefolium is a balanced stimulant, because it achieves arousal without provoking a nervous or jittery response. It does this by simultaneously stimulating the adrenergic (adrenal) nervous system and the cholinergic (calming) nervous system, through the brain's reticular formation.
Panax quinquefolium stops excessive cortisol release by decreasing the demand for cortisol. It does this by increasing the production of adrenaline, but not the release of adrenaline. When the body's supply of adrenaline is increased, it has no need to release cortisol in response to stressful situations.
When Panax quinquefolium is regularly ingested the adrenal response to a stressful situation is faster and more adrenaline is released. As a reaction to this abundance of adrenaline, the hypothalmus and the pituitary gland, which control the release of cortisol, 'decide' not to produce cortisol. Further, Panax quinquefolium biochemically enables the adrenals to 'shut off' more quickly, once the stressful situation has passed.
Panax quinquefolium heightens cognitive function but its ability to evoke a more stable state of arousal, while enabling quick reaction times.
A reasonable daily dosage may range from 750 mg to 1500mg, depending on you and the quality of your ginseng.