Ginseng (American)

Ginseng (American)

Ginseng (American)

Common Names

  • Xi yang shen
  • Tienchi ginseng
  • western ginseng
  • five-fingers

For Patients & Caregivers

Bottom Line: American ginseng has not been shown to treat or prevent cancer.

American ginseng has been shown to lower blood sugar levels in humans. Scientists think that the medicinal properties of this herb come from its components called ginsenosides. Most research has been done on another species, Panax ginseng. These studies indicate that ginsenosides both stimulate and inhibit the central nervous system in humans and stimulate the immune system in mice.
American ginseng was shown to reduce the number and severity of colds, and improve working memory in healthy adults.
It also showed anticancer properties in lab studies, and may be useful in reducing cancer-related fatigue.
American ginseng decreases the anticoagulant effects of warfarin, a commonly used anticoagulant.

  • To improve athletic performance
    No scientific evidence supports this use.
  • To prevent and treat cancer
    There are no data to back this claim. But American ginseng helps improve cance-related fatigue and improves quality of life.
  • To treat diabetes
    A few studies show a blood glucose-lowering effect of American ginseng.
  • To stimulate the immune system
    Some studies show an immunostimulant effect in animals. Human data are lacking.
  • For increased strength and stamina
    Although American ginseng is often promoted for this use, human data are lacking.

Cancer-related fatigue:
In this study, 364 fatigued cancer survivors were randomized to receive 2000mg of American ginseng or a placebo for 8 weeks. Those who took American ginseng had significant improvement in their fatigue. Patients who were undergoing active treatment benefited more than those who completed treatment. No serious side effects were reported.

Interaction with Warfarin:
Twenty healthy adults received warfarin during weeks 1 and 4 in this study. They were then randomized to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects who received American ginseng had signficantly lowered International Normalized Ratios (INR) when compared with those receiving placebo. Researchers conclude that American ginseng reduces warfarin’s anticoagulant effect.

  • You are taking warfarin or other blood thinners (American ginseng may interfere with the action of the anticoagulant).
  • You are taking drugs that are substrates of cytochrome P450 (CYP) 3A4 (American ginseng may make the drugs less effective).

Breast cancer patients should use this product with caution as American ginseng may stimulate the growth of breast cancer cells.

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For Healthcare Professionals

Panax quinquefolius

A popular herb often confused with Asian or Panax ginseng, American ginseng has unique medicinal properties. It is frequently used in Chinese medicine to nourish “Yin” (1). American ginseng is also used in supplemental form to improve athletic performance, strength and stamina, and to treat diabetes and cancer. The saponin glycosides, also known as ginsenosides or panaxosides, are thought responsible for the herb’s biological effects.
Ginsenosides have both stimulatory and inhibitory effects on the CNS (4), alter cardiovascular tone, enhance humoral and cellular-dependent immunity, and exert anticancer effects in vitro (3)(15)(16).

Current data suggest that American ginseng may improve glucose control in diabetics (2)(6), and that it is safe for long-term use (25). It also demonstrated a modest effect in reducing the number and severity of colds (12); and enhanced working memory in healthy adults (21) and in patients with schizophrenia (24).

The anticancer activity of American ginseng was enhanced when combined with antioxidants (14). In other studies, the herb showed synergistic effects with 5-fluorouracil against colorectal cancer cells (17); and conferred protection against oxidative stress in irradiated human lymphocytes (18).
Data from an epidemiological study indicate that American ginseng improves survival and quality of life in breast cancer patients (13). Findings from a randomized controlled trial support its benefits in improving cancer-related fatigue (23).

  • Cancer prevention
  • Cancer treatment
  • Diabetes
  • Health maintenance
  • Immunostimulation
  • Strength and stamina
  • Saponin glycosides: Panaquilon, ginsenosides
  • Volatile oils
  • Antioxidants
  • Polysaccharides
  • Fatty acids
  • Vitamins
  • Polyacetylenes
    (5)

Ginsenosides are thought responsible for American ginseng’s activity, although the exact mechanism of action is unknown.
Related species, such as Panax ginseng, have been the focus of most laboratory and clinical research. Experiments using extracts from these species indicate that ginsenosides stimulate and inhibit the CNS (4). The extracts also stimulate TNF alpha production by alveolar macrophages (10).

The Rg1 ginsenoside present in American ginseng is associated with improvements in humoral and cell-mediated immune response and increases in T helper cells, T lymphocytes, and NK cells in mice (5). American ginseng was also shown to lower serum glucose and may affect carbohydrate metabolism (2)(6).

Several ginsenosides demonstrated anticancer properties in vitro (3). Current data suggest that the antiproliferative effects of American ginseng are due to compound K, a metabolite of the ginsenoside Rb1, but not Rb1 as previously thought (22).
In another study, the herb was shown to significantly attenuate azoxymethane/dextran sodium sulfate (DSS)-induced colon carcinogenesis by reducing the colon tumor number and tumor load, associated with suppression of DSS-induced proinflammatory cytokine activation (26).

In a rabbit model, the pharmacokinetics of ginsenosides A1, A2, B2, and C were best described with a one-component open model. Ginsenoside C (protopanaxadiol group ginseng saponin) showed a significantly longer half-life, higher plasma protein binding, and lower metabolic and renal clearance compared to A1, A2, and B2 (protopanaxatriol group ginseng saponins).
All ginsenosides except ginsenoside A1 were absorbed slowly after intraperitoneal administration. Ginsenosides were not found in rabbit plasma or urine samples after oral administration.
In mice, ginsenoside C was more toxic than ginsenoside A2 following intraperitoneal administration.
None of the ginsenosides caused toxicity following oral administration. (5)

Breast cancer patients should use this product with caution as American ginseng may stimulate the growth of breast cancer cells (9).

Warfarin: American ginseng has been shown to antagonize warfarin’s effects (11).
Cytochrome P450 (CYP) 3A4 substrates: Certain ginsenosides can induce CYP3A4 and may affect the metabolism of some drugs that are substrates of this enzyme (19)(20).

Reductions in PT, PTT, and INR and blood glucose may occur.
(8)(11)

Barton DL, Liu H, Dakhil SR, et al. Wisconsin Ginseng (Panax quinquefolius) to improve cancer-related fatigue: a randomized, double-blind trial, N07C2. J Natl Cancer Inst. 2013 Aug 21;105(16):1230-8.
In this phase III trial, 364 fatigued cancer survivors were randomized to 2000mg of American ginseng or a placebo for 8 weeks. The primary endpoint was the general subscale of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) at 4 weeks. Deviations from the baseline were measured at 4 and 8 weeks by a two-sided, two-sample t test. Toxicities were determined by self-report and the National Cancer Institute’s Common Terminology Criteria for Adverse Events (CTCAE) provider grading.
Researchers reported that changes in the MFSI-SF were 14.4 (standard deviation [SD] = 27.1) in the American ginseng group vs 8.2 (SD = 24.8) in the placebo group at 4 weeks (P = .07). At 8 weeks, a statistically significant difference was observed with a change score of 20 (SD = 27) for the American ginseng group and 10.3 (SD = 26.1) for the placebo group (P = .003). Patients undergoing active cancer treatment benefited more compared to those who had completed treatment. There were no adverse effects following supplementation.

Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin’s effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.
Twenty healthy adults took part in a four-week trial of American ginseng and its effects on warfarin. All subjects received warfarin during weeks 1 and 4. Subjects were randomly assigned to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects receiving American ginseng had significantly decreased International Normalized Ratios (INR) when compared with those receiving placebo. Peak INR and peak plasma warfarin levels were correlated. Researchers concluded that American ginseng reduces warfarin’s anticoagulant effect.


  1. Huang KC. The Pharmacology of Chinese Herbs, 2nd ed. New York: CRC Press; 1999.

  2. Attele AS, Wu JA, Yuan CS. Ginseng pharmacology: multiple constituents and multiple actions. Biochem Pharmacol 1999;58:1685-93.

  3. Chen SE. American ginseng. III. Pharmacokinetics of ginsenosides in the rabbit. Eur J Drug Metab Pharmacokinet 1980;5:161-8.

  4. Brinker F. Herb Contraindications and Drug Interactions, 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.

  5. Amato P, Christophe S, Mellon PL. Estrogenic activity of herbs commonly used as remedies for menopausal symptoms. Menopause 2002;9:145-50.

  6. Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin’s effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.

  7. Li B, Wang CZ, He TC, et al. Antioxidants potentiate American ginseng-induced killing of colorectal cancer cells. Cancer Letters. 2010;289(1):62-70.

  8. Xie JT, Du GJ, McEntee E, et al. Effects of Triterpenoid Glycosides from Fresh Ginseng Berry on SW480 Human Colorectal Cancer Cell Line. Cancer Res Treat. 2011 Mar;43(1):49-55.

  9. Li XL, Wang CZ, Sun S, et al. American ginseng berry enhances chemopreventive effect of 5-FU on human colorectal cancer cells. Oncol Rep. 2009 Oct;22(4):943-52.

  10. Lee TK, O’Brien KF, Wang W, et al. Radioprotective effect of American ginseng on human lymphocytes at 90 minutes postirradiation: a study of 40 cases. J Altern Complement Med. 2010 May;16(5):561-7.

  11. Barton DL, Liu H, Dakhil SR, et al. Wisconsin Ginseng (Panax quinquefolius) to improve cancer-related fatigue: a randomized, double-blind trial, N07C2. J Natl Cancer Inst. 2013 Aug 21;105(16):1230-8.

  12. Mucalo I, Jovanovski E, Vuksan V, Božikov V, Romić Z, Rahelić D. American Ginseng Extract (Panax quinquefolius L.) Is Safe in Long-Term Use in Type 2 Diabetic Patients. Evid Based Complement Alternat Med. 2014;2014:969168.

  13. Yu C, Wen XD, Zhang Z, et al. American ginseng attenuates azoxymethane/dextran sodium sulfate-induced colon carcinogenesis in mice. J Ginseng Res. 2015 Jan;39(1):14-21.

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