American Ginseng
What American ginseng (Panax quinquefolius) is, how it differs from Asian ginseng, what trials found for colds and blood sugar, the warfarin finding, and wild-harvest concerns.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
What is American ginseng good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Possible shorter or fewer colds
Preliminary or mixedA review of five trials in healthy adults found insufficient evidence that it prevents colds, but two trials found colds were shorter when it was taken for 8 to 16 weeks.
Supplements: Evidence is limited and the review's overall conclusion was insufficient.
Possible modest blood sugar lowering in type 2 diabetes
Preliminary or mixedIn one small crossover trial of 24 adults with type 2 diabetes on usual treatment, an extract lowered HbA1c and fasting glucose compared with placebo.
Supplements: Single small trial; does not replace diabetes treatment.
Cancer-related fatigue
Preliminary or mixedMSK summarises a large multisite trial and a guideline supporting its use for fatigue during cancer treatment; the trial itself was not read, and one meta-analysis found ginseng alone did not reduce fatigue.
Supplements: Summary-level evidence only; not shown for general tiredness.
Possible blood pressure and LDL changes
Preliminary or mixedThe same small diabetes trial reported lower systolic blood pressure and LDL cholesterol. This was a secondary finding in one study.
Supplements: Not established.
Memory and thinking
Not enough evidenceMSK mentions possible working-memory improvements, while a Cochrane review of ginseng found no convincing evidence for cognition. Results are unclear.
Supplements: No reliable evidence of benefit.
Traditional use to nourish Yin
Not enough evidenceIn Chinese medicine it is used to nourish Yin. This is traditional use, not evidence of effect.
Supplements: Not evidence of benefit.
Laboratory effects of ginsenosides
Lab or animal research onlyLab studies attribute effects (including on the nervous system and cancer cells) to ginsenosides, and one study found stimulated breast cancer cell growth at doses MSK says cannot be reached orally. These lab findings do not show effects in people.
Supplements: Lab findings only.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (2)
- Blood Sugar BalancePreliminary or mixed
One small crossover trial of 24 adults with type 2 diabetes on usual treatment found lower HbA1c and fasting glucose with an extract. It is a single small study and is not a replacement for diabetes care.
- Immune SupportPreliminary or mixed
A systematic review of five trials in healthy adults found insufficient evidence that it prevents colds, though two trials found colds were shorter when taken for 8 to 16 weeks.
Body systems (3)
- Blood Sugar SupportPreliminary or mixed
A small trial in adults with type 2 diabetes found modest drops in HbA1c and fasting glucose. Larger studies are still needed.
- Immune SupportPreliminary or mixed
Evidence for fewer or shorter colds is limited and mixed; the review called it insufficient to conclude it reduces incidence or severity.
- Immune SystemPreliminary or mixed
Studied mainly for colds in healthy adults, with limited and mixed results.
Body parts (1)
- Immune SystemPreliminary or mixed
Cold-prevention trials gave limited, mixed results; no firm conclusion on immune effects in people.
Functional actions (1)
- Blood Sugar RegulationPreliminary or mixed
Lower HbA1c and fasting glucose were seen in one small crossover trial in people with type 2 diabetes. It is not proven in larger trials.
Root causes (2)
- Medication Side EffectsDocumented risk
In a trial in 20 healthy volunteers it lowered warfarin's blood-thinning effect, and glucose lowering means diabetes medicines may need monitoring. Ask the prescriber or pharmacist before combining.
- Blood Sugar ImbalancePreliminary or mixed
Studied as an add-on in type 2 diabetes with modest glucose changes in one small trial. This is not a substitute for medical treatment.
Biomarkers (2)
- Blood GlucosePreliminary or mixed
Fasting blood glucose was lower than with placebo in the same small trial; MSK also notes blood glucose may fall.
- HbA1cPreliminary or mixed
HbA1c fell by 0.29% compared with placebo in one small crossover trial in adults with type 2 diabetes.
Conditions & symptoms (3)
- Acute Upper Respiratory InfectionPreliminary or mixed
The same review included acute respiratory infections; results were tentative.
- Common ColdPreliminary or mixed
A review found insufficient evidence it prevents colds, though two trials found them shorter when taken for 8 to 16 weeks.
- Type 2 Diabetes Mellitus Without ComplicationPreliminary or mixed
One small trial found modest improvements in HbA1c and fasting glucose as an add-on to usual treatment. Not a replacement for diabetes care.
Documented risks and interactions (4)
- Possible effect on warfarin (reduces its action). In a small trial in healthy volunteers, American ginseng lowered warfarin levels and its effect on INR. Anyone on warfarin should ask the prescriber or pharmacist first.
- Interaction with diabetes medicines. Because blood glucose may fall, people using diabetes medicines should ask a clinician before adding it.
- Possible effect on other medicines (CYP3A4). Lab work suggests certain ginsenosides may induce the CYP3A4 enzyme and affect medicines cleared by it. Clinical relevance is not determined.
- Wild harvest and conservation. Wild American ginseng is listed on CITES Appendix II after long-term harvesting. This concerns the plant, not human health.
What it is
American ginseng is Panax quinquefolius L., in the Araliaceae family. [5] The trials we read used root extract. [6] It is a different species from Asian ginseng (Panax ginseng), and Memorial Sloan Kettering says it has unique medicinal properties and is often confused with it. [2] In traditional Chinese medicine it is described as nourishing "Yin". [2] Research on one ginseng does not transfer to the other. See Asian versus American ginseng and ginseng types compared.Is it an "adaptogen"?
"Adaptogen" is a contested term. In the sources we read, the label is attached to Panax ginsengs in general; we did not find a source that classifies American ginseng specifically. See what adaptogens are.Traditional use (not proof)
Memorial Sloan Kettering says American ginseng is frequently used in Chinese medicine to nourish Yin. [2] See ginseng in Chinese medicine. This is traditional use and is not evidence of effect.What research shows
| Use | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Preventing colds | A systematic review of five trials (747 healthy adults, all using North American ginseng) found a 25% drop in total colds in one trial and a trend toward fewer infections; it concluded there is insufficient evidence that ginseng reduces incidence or severity. Two trials found colds shorter by 6.2 days when taken preventively for 8 to 16 weeks. [6] | Promising but limited | Healthy adults; root extract |
| Blood sugar in type 2 diabetes | In a crossover trial of 24 adults already treated for type 2 diabetes, an extract (1 g per meal for 8 weeks) lowered HbA1c by 0.29% and fasting glucose compared with placebo. [7] | Promising but limited | Adults aged about 64; extract added to usual care |
| Cancer-related fatigue | Memorial Sloan Kettering's summary says a large multisite trial reported benefit and that oncology guidelines recommend it; we did not read the trial itself. [2] | Promising but limited (summary only) | People in cancer treatment |
NIH's complementary health center does not have a page on American ginseng that we could read, so we do not state an NIH conclusion for this species. For ginseng as a group, a Cochrane review found a lack of convincing evidence for thinking. [8]
Wild harvest and conservation
A review in the Annals of the New York Academy of Sciences says harvesting for the Asian traditional medicine market made ginseng North America's most harvested wild plant for two centuries and led to a listing on CITES Appendix II. [9] Simulation work found that harvest plus climate warming raised the modeled extinction risk of populations far above either alone, and its authors argue harvest rules should account for climate change. [10] Harvest rules are set by governments; this page gives no harvesting or identification instructions. See adaptogen regulation and conservation.Quality
Whole root, extract and powder products differ, and the trials above used specific extracts. See standardized extracts and quality testing and certifications.Where to go next
Ginseng blood sugar, blood thinners and other cautions and adaptogens and blood pressure and sugar.Frequently asked questions
Does American ginseng prevent colds?
A review found insufficient evidence it reduces how often colds occur, but some trials suggested shorter colds. [6]
Is it the same as Asian ginseng?
No. They are different species with separate research and cautions. [2]
Does it interact with warfarin?
A randomized trial found it reduced warfarin's effect in healthy volunteers. Ask the prescriber or pharmacist. [1]
Is American ginseng endangered?
The review we read says wild harvest led to a CITES Appendix II listing and describes threats to wild populations. [9]
Can it lower blood sugar?
A small crossover trial found lower HbA1c and fasting glucose in adults with type 2 diabetes. [7]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety points first
- Warfarin. In a placebo-controlled trial of 20 healthy volunteers, American ginseng lowered peak INR and warfarin levels compared with placebo, meaning it reduced warfarin's blood-thinning effect; the authors noted the volunteers were young and healthy rather than patients on usual doses. [1] Memorial Sloan Kettering Cancer Center's clinician section says American ginseng antagonizes warfarin's effects in humans, while its patient section says it may increase bleeding risk; the two statements point in different directions, so ask the prescriber or pharmacist and do not change warfarin yourself. [2]
- Diabetes medicines. Trials show glucose-lowering effects (below), so people using diabetes medicines should ask a clinician before adding it. A review of herbs and warfarin also notes American ginseng changed warfarin's effects in trials, unlike the other ginsengs tested. [3]
- Pregnancy, breastfeeding, children, liver and kidney conditions. Proper evidence not found. We searched for American ginseng safety in these groups in PubMed, Europe PMC and Memorial Sloan Kettering and found no specific statement. The European herbal committee's statements about Panax ginseng (a different species) should not be transferred without a clinician's advice. [4]
- Other medicines. Memorial Sloan Kettering notes laboratory work suggesting certain ginsenosides may induce CYP3A4 and affect medicines cleared by it, with clinical relevance not determined. [2]
References
- Yuan et al. Brief communication: American ginseng reduces warfarin's effect in healthy patients: a randomized, controlled Trial. Annals of internal medicine 2004. PubMed 15238367. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. American Ginseng: Purported Benefits, Side Effects & More. Information About Herbs, Botanicals and Other Products. Read 2026-10-23.
- Choi et al. A systematic review of the pharmacokinetic and pharmacodynamic interactions of herbal medicine with warfarin. PloS one 2017. PubMed 28797065. Read 2026-10-23.
- European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). European Union herbal monograph on Panax ginseng C.A.Mey., radix (EMA/HMPC/27744/2023, final revision 1, 29 May 2024). Read 2026-10-23.
- GBIF Secretariat. GBIF Backbone Taxonomy. Names checked through the species match API on 2026-10-23. Read 2026-10-23.
- Seida et al. North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) Preparations for Prevention of the Common Cold in Healthy Adults: A Systematic Review. Evidence-based complementary and alternative medicine : eCAM 2011. PubMed 19592479. Read 2026-10-23.
- Vuksan et al. Efficacy and safety of American ginseng (Panax quinquefolius L.) extract on glycemic control and cardiovascular risk factors in individuals with type 2 diabetes: a double-blind, randomized, cross-over clinical trial. European journal of nutrition 2019. PubMed 29478187. Read 2026-10-23.
- Geng et al. Ginseng for cognition. The Cochrane database of systematic reviews 2010. PubMed 21154383. Read 2026-10-23.
- McGraw et al. Ecology and conservation of ginseng (Panax quinquefolius) in a changing world. Annals of the New York Academy of Sciences 2013. PubMed 23398402. Read 2026-10-23.
- Souther et al. Synergistic effects of climate change and harvest on extinction risk of American ginseng. Ecological applications : a publication of the Ecological Society of America 2014. PubMed 29160667. Read 2026-10-23.