(See also Overview of Dietary Supplements.)
Ginseng is a family of plants. Dietary supplements are derived from American ginseng (Panax quinquefolius) or Asian ginseng (Panax ginseng). Siberian ginseng (Eleutherococcus senticosus) is a different genus and does not contain the ingredients believed to be active in the 2 forms used in supplements.
Ginseng can be taken as fresh or dried roots, extracts, solutions, capsules, tablets, sodas, and teas or used as cosmetics. Active ingredients in American ginseng are panaxosides (saponin glycosides). Active ingredients in Asian ginseng are ginsenosides (triterpenoid glycosides).
Many ginseng products contain little or no detectable active ingredient. In very few cases, some ginseng products from Asia have been purposefully mixed with mandrake root, which has been used to induce vomiting, or with the drugs phenylbutazone or aminopyrine. These drugs have been removed from the US market because of significant adverse effects.
Ginseng is said to enhance physical (including sexual) and mental performance and to have adaptogenic effects (ie, to increase energy and resistance to the harmful effects of stress and aging). Other claims include reduction in plasma glucose levels; increases in high-density lipoprotein (HDL), Hb, and protein levels; stimulation of the immune system; and anticancer, cardiotonic, endocrine, CNS, and estrogenic effects. Another claim is possible beneficial effects on immune function.
Studies of ginseng have all been limited, for example, by small size and number. Such studies have shown
A Canadian study showed that a polysaccharide extract of P. quinquefolius helped prevent colds (6). A 2010 Cochrane review of 9 randomized, double-blind, placebo-controlled trials evaluated the efficacy and adverse effects of ginseng supplementation taken to improve cognitive function in healthy participants (8 trials) and those with age-associated memory impairment (1 trial) (5). The analysis found no serious adverse events with ginseng supplementation, but there was no convincing evidence for enhanced cognitive function in healthy participants or people with diagnosed dementia.
Larger trials are needed to evaluate the effectiveness of ginseng. Also, further evaluation of the compounds found in the supplements is necessary to determine the components responsible for the observed beneficial effects. There is no evidence supporting other health claims for ginseng.
Nervousness and excitability may occur but decrease after the first few days. Ability to concentrate may decrease, and plasma glucose may become abnormally low (causing hypoglycemia). Because ginseng has an estrogen-like effect, women who are pregnant or breastfeeding should not take it, nor should children. Occasionally, there are reports of more serious effects, such as asthma attacks, increased blood pressure, palpitations, and, in postmenopausal women, uterine bleeding. To many people, ginseng tastes unpleasant.
Assinewe VA, Amason JT, Aubry A, et al. Extractable polysaccharides of Panax quinquefolius L. (North American ginseng) root stimulate TNF-alpha production by alveolar macrophages. Phytomedicine 9(5):398-404, 2002.
Yun TK. Experimental and epidemiological evidence on non-organ specific cancer preventive effect of Korean ginseng and identification of active compounds. Mutat Res 523-524:63–74, 2003.
Reay JL, Kennedy DO, Scholey AB. Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity.J Psychopharmacol 19(4):357-365, 2005.
Kim J, Chung SY, Park S, et al. Enhancing effect of HT008-1 on cognitive function and quality of life in cognitively declined healthy adults: a randomized, double-blind, placebo-controlled, trial. Pharmacol Biochem Behav 90(4):517-524, 2008.
Geng J, Dong J, Ni H, et al. Ginseng for cognition. Cochrane Database Syst Rev (12):CD007769, 2010.
Predy GN, Goel V, Lovlin R, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. CMAJ 173(9):1043-1048, 2005.