Ginseng Side Effects and Warnings

Safety Issues

Ginseng appears to be nontoxic, both in the short- and long-term, according to the results of studies in mice, rats, chickens, and dwarf pigs. ^{1 2 3} Reported side effects are rare. There are a few case reports of breast tenderness, postmenopausal vaginal bleeding, and menstrual abnormalities associated with Panax ginsenguse. ^{4 5 6 7} Such side effects suggest that it has estrogenic properties. However, a large double-blind trial of Panax ginsengfound no estrogen-like effects. ⁸ Another double-blind trial found no effects on estrogen or testosterone, ⁹ and a carefully designed test-tube study showed that ginseng is not estrogenic. ¹⁰ Therefore, it is possible that these apparent side effects were coincidental; another possibility is that adulterants in the ginseng product used caused the problem. Ginseng and other Asian herbal products have often been found to contain unlisted herbs and pharmaceuticals. ¹¹ Estrogen itself stimulates the growth of breast cancer cells. Interestingly, in a test-tube study, Panax ginsengwas again found to be non-estrogenic, and yet it nonetheless stimulated the growth of breast cancer cells. ¹² Although the mechanism of this effect is not known, the results suggest that women who have had breast cancer should avoid using ginseng.

Unconfirmed reports suggest that highly excessive doses of Panax ginsengcan cause insomnia, raise blood pressure, increase heart rate, and possibly cause other significant effects. Whether some of these cases were actually caused by caffeine mixed in with ginseng remains unclear. One double-blind study failed to find any effect on blood pressure. ¹³ One case report and one double-blind trial suggest that Panax ginsengcan reduce the anticoagulant effects of Coumadin (warfarin), ¹⁴ but another trial failed to find such an interaction. ¹⁵ The reason for this discrepancy is not clear, but prudence would nonetheless suggest not combining ginseng and warfarin.

Two reports indicate that combination treatment with Panax ginsengand antidepressant drugs may result in a manic episode. ¹⁶ There are also theoretical concerns regarding use of ginseng by people with diabetes. If it is true, as the preliminary studies discussed above suggest, that ginseng can in fact reduce blood sugar levels, people with diabetes who take ginseng might need to reduce their dose of medication. On the other hand, if certain types of ginseng have the opposite effect (as researchers hypothesize), this could necessitate an increase in medication. The bottom line: people with diabetes should only use ginseng under physician supervision.

In 1979, an article was published in the Journal of the American Medical Associationclaiming that people can become addicted to Panax ginsengand develop blood pressure elevations, nervousness, sleeplessness, diarrhea, and hypersexuality. ¹⁷ However, this report has since been thoroughly discredited and should no longer be taken seriously. ¹⁸ Chinese tradition suggests that Panax ginsengshould not be used by pregnant or nursing mothers, and one animal study hints that ginseng use by a pregnant mother could cause birth defects. ¹⁹ Safety in young children or people with severe liver or kidney disease has not been established.

Interactions You Should Know About

If you are taking:

• Antidepressants: Panax ginsengmight cause manic episodes.

• Insulin or oral hypoglycemics : Various forms of ginseng may unpredictably alter your dosage need.

• Coumadin ( warfarin ): Panax ginsengmight possibly decrease its effect.

• Influenza vaccine : Panax ginsengmight help it work better.

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1. Fugh-Berman, Adriane (2000). "Herb-drug interactions". The Lancet 355 (9198): 134–138. doi:10.1016/S0140-6736(99)06457-0. ISSN 0140-6736.