Ginseng generally refers to the extract of the ginseng root. There are three main varieties -- Siberian Ginseng, Chinese-Panax Ginseng, and American Ginseng. It is reputed to have tonic effects and increases energy levels. Ginseng must be taken for 2 weeks before any effects will be apparent. It has anti-coagulant (dilates blood vessels) properties and neuroprotective effects, but the Asian variety (which is harder to find) can temporarily raise blood pressure like caffeine or ephedra as it raises your energy level. Ginseng can be taken in pill form, extracts, or teas and is often available in commercial beverages.