It is thought to elicit some of its effect by support of the adrenal gland. It has many uses in folk medicine. Works best when taken for a 3 week regimen, then not for a week. Start at the lower dose and advance slowly. Should not be combined with caffeine.
Side effects can include anxiety, euphoria, nervousness, skin eruptions and morning diarrhea.
Chemistry and pharmacology of Panax. In Economic and Medicinal Plant Research, vol 1, ed. H Wagner, H Hikino, NR Farnsworth. Sahi L, et al. In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients.