Drug Profile

Background

Ginseng is a term applying to over 20 different species, mostly of the genus Panax. These include P. ginseng (Asian ginseng), P. japonicus (Japanese ginseng) and P. quinquefolius (American ginseng). These contain triterpene saponin glycosides called ginsenosides, which are claimed to be the source of ginseng’s activity. An unrelated species, Eleutherococci (Siberian ginseng), does not even contain ginsenosides but often is the subject of similar health claims as the Panax species. The terms “red” and “white” ginseng do not refer to different plants; they refer to different methods of preparation.[1] The plants contain many different constituents and there are no generally agreed-upon standards for comparing preparations of ginseng. Thus, herbal remedies labeled “ginseng” may contain various plant extracts and vary from manufacturer to manufacturer and within manufacturers’ batches or lots. Ginseng has been used for centuries in traditional Chinese medicine “to restore and enhance well-being.”[2] Other uses include enhancing mental and physical vigor, easing childbirth, and as an aphrodisiac.[3]

Claimed Uses

A plethora of vague health claims characterize the modern promotion of ginseng; indeed the genus name Panax appears to derive from the Latin word “panacea.”[4] In this section, we generally focus only on those that correspond to claims that can be tested empirically.

We do not address claims about which only animal or test-tube evidence exists, or for which there are no accessible randomized, placebo-controlled trials (e.g., herpes infection, heart failure, hypertension, cancer). We also do not address claims of improvements in physical performance among healthy persons, although the four most recent studies of this topic reportedly show no evidence of effectiveness.[5],[2]

Psychological and Motor Functions

Two randomized trials evaluated ginseng/ginkgo biloba combinations and so were not considered in this evaluation.[6],[7] Another claimed cognitive and mood benefits, but only evaluated the effect of various doses of ginseng in 20 patients for no longer than six hours after a single dose.[8] The final study was not properly randomized but found no effect of various doses of a ginseng preparation upon mood after eight weeks.[3] The only accessible randomized, placebo-controlled study of this claim was small and found a statistically significant benefit for ginseng on only one of eight variables measured.[9]

Stimulation of the Immune System

Although some studies have looked at indirect measures of immune function, none has examined the clinical relevance of these findings.

Diabetes

A study claiming better blood sugar control in patients with diabetes taking ginseng is not credible because only 12 patients took each ginseng dose, follow-up was only eight weeks, and important baseline information on the patients was not provided.[10] A second small study looked only at the immediate effects of ginseng (up to two hours).[11]

Cancer

An epidemiologic study from Korea, where ginseng use is very common, showed an approximately 60 percent reduction in the risk of cancer overall.[12] However, the reduction occurred across multiple disparate organ systems, a finding not consistent with current understandings of how cancer is caused and prevented. Before this finding can be accepted, it would need to be replicated in another study of similar design and then confirmed in a randomized, placebo-controlled trial.

Tonic

One randomized study compared ginseng combined with multivitamins to multivitamins alone in an effort “to remedy the deterioration in quality of life in large cities.” To our knowledge, this is not a recognized medical condition. The claimed benefits on quality of life may be explained by either much larger dropout rates in the control group or improper randomization.[13]

Interactions with Other Drugs

The FDA has warned that ginseng can increase the effectiveness of warfarin (COUMADIN), which could lead to bleeding,[14],[15] including vaginal bleeding.[16] Conversely, ginseng has also been associated with clot formation on an implanted heart valve in a patient taking warfarin.[17] While the warfarin label must warn of an interaction with ginseng, ginseng may be sold without warning of the interaction with warfarin. There are also two reports of interactions between ginseng and phenelzine (NARDIL).[18],[19]

Adverse Effects

Ginseng has been associated with hypertension, nervousness, insomnia, vomiting, headache, skin rashes, and nosebleeds.[20],[21],[22] A ginseng abuse syndrome, involving the simultaneous use of caffeine, has also been described.[23],[24] Its features are hypertension, nervousness, and sleeplessness. Other reports describe estrogen-like effects for ginseng: changes in the lining of the vagina[25] and vaginal bleeding.[26]

The January 2009 Drug and Therapeutics Bulletin reviewed ginseng and other herbal and dietary supplements that are used to treat the symptoms of menopause. The journal found that women should not use these supplements to ease the symptoms of menopause because the products are not effective and many can cause dangerous side effects. The products also have the potential to interact dangerously with other drugs or herbal supplements.[27]

Conclusion

In summary, ginseng is an unstandardized, highly variable preparation with extravagant claims for benefits and no scientific data to support them.