Ginseng refers to two closely related herbs of the genus Panax. Asian ginseng (P. ginseng) and American ginseng (P. quinquefolius) have traditionally been used for healing. Asian ginseng is also known as Korean red ginseng, Chinese ginseng, Japanese ginseng, ginseng radix, ninjin, sang, and ren shen. American ginseng is also known as Canadian ginseng, North American ginseng, Ontario ginseng, Wisconsin ginseng, red berry, sang, and ren shen. Siberian ginseng (Eleutherococcus senticosus) is a plant with different properties that belongs to a completely different genus. Ginseng refers only to Asian and American ginseng of the genus Panax.
Ginseng is a perennial herb that grows in cool, damp, shady forests. Asian ginseng is native to Northern China and is grown as a cash crop in China, Korea, Japan, and Russia. American ginseng once grew wild from the Appalachian Mountains to Minnesota. In the 2010s, it was cultivated mainly in Wisconsin and in the Canadian provinces of Ontario and British Columbia. Most cultivated ginseng from North America is exported to Asia. In both Asia and North America, wild ginseng is threatened with extinction from overharvesting. In the United States, a government permit is usually required to export wild ginseng. High-quality wild ginseng is very expensive. Illegal harvesting of wild ginseng from public lands is an ongoing law enforcement problem for the United States Fish and Wildlife Service.
Ginseng is a slow-growing plant that reaches a height of 12–30 inches (30–76 cm) and produces red berries. Only the root is used for medicinal purposes. Ginseng is difficult to cultivate. Plants must grow for four to six years before the roots can be harvested. Ginseng roots are forked and twisted, looking somewhat like a miniature human body. They are occasionally used fresh but more often are dried and ground or powdered. The root can be soaked to make an extract or tincture. Ground ginseng can be added to tea, and powered ginseng put into capsules. Ginseng extract can be added to products as diverse as chewing gum and soft drinks. Ginseng is sold under dozens of different brand names. It is often found in multi-herbal remedies sold under a variety of names. The active ingredients in ginseng are thought to be more than 20 compounds called ginsenosides. Some manufacturers standardize the amount of ginsenosides in their product, whereas others do not. Standardized products usually contain 4% ginsenosides.
In the United States, ginseng is regulated by the Food and Drug Administration (FDA) as a dietary supplement under the 1994 Dietary Supplement Health and Education Act (DSHEA). At the time the act was passed, legislators believed that, because many dietary supplements such as ginseng come from natural sources and have been used for hundreds of years by practitioners of complementary and alternative medicine (CAM), these supplements did not need to be regulated as rigorously as prescription and over-the-counter drugs used in conventional medicine.
The DSHEA regulates ginseng in the same way that food is regulated. Like food manufacturers, manufacturers of herbal products containing ginseng do not have to prove that their products are either safe or effective before they can be sold to the public. This differs from conventional pharmaceutical drugs, which must undergo extensive human testing to prove their safety and effectiveness before they can be marketed. Also unlike conventional drugs, the label for a dietary supplement such as ginseng does not have to contain any statements about possible side effects. All herbal supplements sold in the United States must show the scientific name of the herb on the label. Consumers should look for ginseng of the Panax variety. Sometimes less expensive herbs such as Siberian “ginseng” are substituted for true ginseng.
Dozens of health claims are made for ginseng, many based on traditional or folk use of the herb. These claims are difficult to substantiate in ways that satisfy conventional medicine for several reasons, including:
Despite these drawbacks, enough evidence exists to indicate that ginseng provides health benefits that the National Center for Complementary and Integrative Health (NCCIH), a government organization within the National Institutes of Health (NIH), sponsors ongoing clinical trials to determine safety and effectiveness of ginseng as a treatment for several diseases and disorders. In 2018, for example, trials were studying the use of ginseng in disorders including colorectal cancer, depression, cold hypersensitivity, chronic fatigue syndrome, and hypertension.
In addition, researchers all over the world regularly study ginseng's effects on various conditions, ranging from sperm production to obesity to aging.
Some health claims for ginseng appear more promising than others. Evidence has shown that ginseng can cause short-term improvement in mental performance in both healthy young adults and elderly ill adults. Not enough information is available to determine if long-term gains also occur, but the results have been promising enough that ginseng is being studied in patients with Alzheimer's disease and other dementias. Along with improved mental performance, some studies have shown that ginseng improves the sense of well-being and quality of life. Results of these studies are mixed, with some finding improvements and others finding no change. The situation is complicated by the fact that different studies define and measure “well-being” and “quality of life” in different ways. In general, people with the worst quality of life report the most improvement.
Many claims are made that ginseng boosts the immune system, thus helping to prevent disease and promote a more rapid recovery from illness and injury. Some studies also claim that ginseng boosts the effect of antibiotics and improves the body's response to influenza vaccines. Some studies of patients with diseases that cause a low white cell count (white cells are a part of the immune system) show that white cell count increases with high doses of ginsenosides. Better studies are needed before the effect of ginseng on the immune system can be determined.
Emerging evidence indicates that ginseng lowers blood sugar in people with type 2 (noninsulin dependent) diabetes. A 2014 meta-analysis of 16 randomized controlled trials in people with and without diabetes concluded that ginseng modestly, yet significantly, improved fasting blood glucose in people with and without diabetes. For better assessment of ginseng's antidiabetic efficacy, larger and longer randomized-controlled clinical studies, using standardized ginseng preparations, are warranted.
Ginseng has been promoted as a preventative and/or cure for cancer, including breast, liver, lung, skin, and colon cancer. Controversial evidence from some studies done in Asia suggests the possibility that ginseng powder or extract may prevent some cancers. More and better studies are needed to clarify these results. Research in the 2010s indicated that ginseng might inhibit the growth of colorectal cancer cells.
Studies of the effect of ginseng on the circulatory system are mixed. Some researchers have found that ginseng lowers blood pressure and, in combination with other herbs, prevents coronary artery disease and possibly congestive heart failure. Other studies have found no effect, or that the effect is apparent only at very high, and possibly unsafe, doses. The effect of ginseng on the circulatory system continues to be investigated.
Many other health claims are made for herbal mixtures that contain ginseng. These claims are extremely difficult to evaluate because of the number of variables, including the strength of the mixture, the effects of the different herbs, and potential interactions among other herbs. Until much more is known about the chemical properties and active ingredients of common medicinal herbs, it is almost impossible to evaluate these mixtures in a way that satisfies the demands of conventional medicine.
Ginseng is generally safe and causes few side effects when taken at recommended doses. The generally recommended dose is 100–200 mg of standardized ginseng extract containing 4% ginsenosides once or twice daily. The safety of ginseng in children and pregnant and breastfeeding women has not been studied. Pregnant and breastfeeding women also should be aware that some tinctures of ginseng contain high levels of alcohol. Some herbalists recommend that individuals take ginseng for two to three weeks and then take a break of one to two weeks before beginning the herb again.
Independent laboratory analyses have repeatedly found that many products labeled as ginseng contain little or none of the herb. True ginseng is expensive, and unscrupulous manufacturers often substitute lowcost herbs for ginseng. Another problem is that some ginseng products have been found to be contaminated with pesticides and other chemicals that can cause serious side effects.
Ginseng appears to interact with blood-thinning and anticoagulant medicines such as warfarin (Coumadin), clopidogrel (Plavix), aspirin, and nonsteroidal anti-inflammatory drugs (e.g., Advil, Motrin). Individuals taking these drugs should not begin taking ginseng without consulting their healthcare providers.
Because ginseng lowers blood sugar levels, individuals who are taking insulin or other medications that also lower blood sugar, and those with type 2 diabetes, should be monitored for low blood sugar if they begin taking ginseng. Adjustments may be needed in their other medications.
Ginseng may also interact with monoamine-oxidase inhibitors (MAOIs) used to treat certain kinds of depression and mental illness. Examples of MAOIs include isocarboxazid (Marplan), phenelzine (Nardil), and tranylcypromine (Parnate). Individuals taking MAOIs with ginseng may develop headaches, tremors, increased anxiety, restlessness, sleeplessness, or mania.
Preliminary evidence suggests that ginseng may interact with certain blood pressure and heart medications. The herb may also interfere with the way the liver processes other drugs and herbs. Before beginning to take a supplement containing ginseng, individuals should review their current medications with their healthcare provider to determine any possible interactions.
Serious side effects of ginseng are rare. The most common side effects are increased restlessness, insomnia, nausea, diarrhea, and rash. Allergic reactions are possible, but uncommon. Some of the more serious side effects reported are thought to be the result of contamination with pesticides, heavy metals, or other chemicals rather than a side effect caused by ginseng.
See also Asian diet ; Dietary supplements ; Ginkgo biloba .
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National Center for Complementary and Integrative Health (NCCIH), 9000 Rockville Pike, NIH Campus, Bldg. 31, Bethesda, MD, 20892, (888) 644-3615, https://nccih.nih.gov/tools/emailnccih , https://nccih.nih.gov .
Office of Dietary Supplements, National Institutes of Health, 6100 Executive Blvd., Rm. 3B01, MSC 7517, Bethesda, MD, 20892-7517, (301) 435-2920, Fax: (301) 480-1845, firstname.lastname@example.org, https://ods.od.nih.gov .
Tish Davidson, AM
Revised by Amy Hackney Blackwell, PhD