Other common name(s): Panax ginseng, Asian ginseng, Oriental ginseng, Chinese ginseng, Japanese ginseng, Korean ginseng, American ginseng, Wisconsin ginseng, man root
Scientific/medical name(s): Panax ginseng C. A. Meyer, Panax quinquefolius
Asian ginseng (Panax ginseng) is a perennial plant grown in China, Korea, Japan, and Russia. American ginseng (Panax quinquefolius), a plant with similar properties, is grown mainly in the United States. Both Amerian and Asian ginseng contain ginsenosides, which are thought to be the active components of the herb. The dried roots of the ginseng plants are sold as dietary supplements. The fresh and dried roots are also used in some traditional medicines to treat a variety of conditions.
The 2 species of ginseng plants of the Panax genus discussed here should not be confused with Siberian ginseng (also known as eleuthero), which has different properties (see our document Eleuthero).
Available scientific evidence does not support claims that ginseng is effective in preventing or treating cancer in humans. Some studies done in the laboratory suggest some substances in ginseng may have anticancer properties. Some population studies in Asia link it to lower cancer risk, but these kinds of studies cannot show cause and effect because many other factors can change the results. Clinical trials are still needed to determine whether it is effective in people. Ginseng should be used cautiously, as it can cause undesirable side effects in high doses and may even be dangerous when taken with certain medicines or if the patient is undergoing surgery.
How is it promoted for use?
Ginseng is an ancient herb that is claimed to help the body prevent and fight diseases, including cancer. Promoters claim ginseng enhances athletic performance and provides energy to people who are stressed or fatigued. It is sometimes used during recovery from illness. There are also claims ginseng relieves depression and anxiety, protects the heart, strengthens digestive functions, prevents hardening of the arteries, stabilizes blood pressure and insulin levels, helps with erectile dysfunction, and even delays the effects of aging. Asian ginseng is used by Western people as a stimulant to make people more active, but in Traditional Chinese Medicine (TCM), it’s used to make people feel calmer. Some people think American ginseng helps fight infections, such as colds and flu. Both types are used for insomnia, loss of appetite, anemia, diabetes, and nerve pain.
Asian ginseng and American ginseng have some differences. Asian ginseng has a stronger smell, and is often used for cooking and flavoring in Asian foods and drinks. Both Asian and American ginseng are also used as dietary supplements in Asian countries.
In the US, both types of ginseng are used mainly as dietary supplements, though they are sometimes added to drinks or foods.
What does it involve?
Ginseng is available as a powder, capsule, tea, or is sometimes sold already mixed with foods. There is no standard dosage; however, Commission E (Germany's regulatory agency for herbs) suggests taking 1 to 2 grams per day of ginseng root for up to 3 months. Dosages are smaller for the dried root powder and extracts, around 200 to 600 mg a day.
True ginseng has the word Panax as part of its Latin, or scientific, name. Even when the same plant type is used, there is variation in quality and strength among ginseng products. Since ginseng is relatively expensive, some packagers may dilute it or substitute less expensive ingredients. Some ginseng products are mislabeled. A 1978 study of 54 ginseng products found that one quarter of them contained no ginseng at all. A 2001 study used a smaller sample of products from the same health food store. All the products contained at least some ginseng, but the amounts of known constituents (ginsenosides) varied by as much as 15-fold in capsules and 36-fold in liquids. In this study, the products were not tested for contaminants, so they may or may not have contained other substances. To the best of our knowledge, more recent studies testing US products haven’t been published in the available medical literature.
What is the history behind it?
The Chinese have been using ginseng for thousands of years as an herbal remedy. Early Chinese books listing curative foods claimed ginseng could enlighten the mind and increase wisdom. The Chinese also used ginseng to treat ailments of the digestive and respiratory systems, nervous disorders, diabetes, to keep the elderly warm in winter, and to increase energy and improve memory. Ginseng was first described as having life-prolonging effects during China's Liang Dynasty (220–589 AD).
American ginseng was discovered growing in the mountains of Quebec by a Jesuit priest in the early 1700s. It was soon exported to China, where it was used in traditional medicines. Ginseng was not used much outside of Asia until the 1950s, when scientists in the Soviet Union began studying its health benefits and concluded that it was an “adaptogen”—that is, something that helps the body adapt to outside stresses and ward off disease. The Vietcong used it extensively to treat gunshot wounds during the Vietnam War.
In 1978, Taik-Koo Yun, MD, from the Korea Cancer Center Hospital in Seoul, began to conduct cohort and case-control studies to investigate whether ginseng might have anticancer properties. He has published articles arguing that ginseng can prevent most cancers, but these types of studies cannot prove that ginseng is the reason that some groups have less cancer. He has encouraged more worldwide study of this herb.
What is the evidence?
Most studies of ginseng have been done in China and Korea. Only recently has ginseng received much research attention in Western countries. The available evidence does not show whether the herb can help prevent or treat cancer.
The effects of ginseng are thought to be due to a group of about two dozen substances in the root called ginsenosides, which resemble steroid hormones. Some differences have been found between Asian and American ginseng when samples have been analyzed. The levels of a few types of ginsenosides vary between them. The side effects of the American and Asian are thought to be similar.
In laboratory research using cell cultures and animals, some ginsenosides found in both Asian and American ginseng have been shown to boost the immune system or slow the growth of cancer cells. Some may also have anti-inflammatory and antioxidant effects. Whether these properties will translate into anticancer activity in humans is still not clear, as few human studies have been done.
Several case-control studies and ecologic studies done in Korea have found that people who took ginseng extract seemed to have a lower risk of cancer overall. However, observational studies cannot completely control for all potential factors that may affect cancer risk. One 2006 Chinese study suggested that women with breast cancer who used either American or Asian ginseng before their diagnosis survived longer than those who did not, although there were other major differences in the groups that took ginseng and those that didn’t. For example, the women who took ginseng were less likely to be very poor, and were more likely to take a conventional hormonal medication (tamoxifen) as part of their breast cancer than the women who didn’t take ginseng. These are factors that are known to affect survival in other studies. The same 2006 study found that the women who used ginseng during treatment reported better quality of life than those who did not. These studies were not the most scientifically convincing, however, and the authors point out that further research is needed to determine the true benefit of ginseng both in cancer prevention and for people who have cancer. A 2013 study looked at more than 300 patients with cancer, and found that those who took 2000 mg (2 grams) of American ginseng each day for 8 weeks reported less fatigue than those who got placebo pills. Researchers are continuing to look at ginseng’s possible effects on cancer-related fatigue.
The benefits of ginseng for other medical conditions have not been shown conclusively, although research is ongoing. Many studies of this herb have suffered from design problems, and results have been contradictory. Some studies have found that it raises blood pressure while others have reported that it lowers blood pressure. In some studies, ginsenosides seem to act as stimulants, but in others they seem to work as sedatives. The only conclusions that can be reached with any certainty at this time are that ginseng is a complex herb and that its medicinal effects are not clearly defined.
A systematic review of randomized clinical trials evaluated the evidence of ginseng root extract’s effectiveness. Based on data from sixteen studies, the researchers concluded that ginseng root extract had not been shown to have a significant effect on physical performance, diabetes, herpes infections, psychomotor performance, cognitive function, or the immune system. More research into its medicinal properties is needed.
Are there any possible problems or complications?
This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must be tested before being sold), the companies that make supplements are not required to prove to the Food and Drug Administration that their supplements are safe or effective, as long as they don't claim the supplements can prevent, treat, or cure any specific disease.
Some such products may not contain the amount of the herb or substance that is on the label, and some may include other substances (contaminants). In a 2013 study, a test of 44 samples found that fewer than half the herbal supplements tested contained any of the herb that was listed on the label. More than half the samples contained compounds that were not on the label. This suggests that the 2007 FDA rules to assure the proper listing of supplement ingredients are not always followed. Even when they are, the rules do not address the safety of the ingredients or their effects on health.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.
Ginseng is generally considered safe, although there are some possible side effects, especially at higher doses. Side effects may include increased heart rate, nausea, headaches, trouble sleeping, and restlessness. Possible effects in women may include swollen breasts and vaginal bleeding. Ginseng may lower blood sugar levels, a side effect that could be of particular importance to people taking medicine for diabetes.
Because both American and Asian ginseng may have steroid hormone–like effects, some doctors caution against their use in women who have had breast, ovarian, or endometrial (uterine) cancer. Not enough study has been done to show whether ginseng is safe for women who are pregnant or breast-feeding. Women who fall into these groups should speak with their doctors before taking ginseng.
Ginseng can have an effect on how long it takes for bleeding to stop. This could be an issue if ginseng is taken before surgery or if the patient is taking drugs that affect blood clotting, such as aspirin, warfarin (Coumadin), dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), clopidogrel (Plavix), heparin injections, or other blood thinners.
Ginseng may cause headaches, tremors, agitation, and has been reported to rarely cause manic episodes, especially if used with antidepressants known as MAOIs such as phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan), or selegiline (Emsam).
Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
To learn more
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our website (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 06/04/2014