Ginseng, Blood Sugar, Blood Thinners and Other Cautions

Ask a pharmacist or clinician before using ginseng if you take warfarin or another blood thinner, if you have diabetes, if you are pregnant or breastfeeding, if you have an autoimmune condition, or if surgery is planned. NIH says Asian ginseng may lower blood sugar, may worsen autoimmune disorders and may interfere with blood clotting, and that it might interact with certain medicines. [1] Never start, stop or change a prescribed medicine because of an herb; ask the prescriber or pharmacist. Overall background: how medicine interactions work.

Which ginseng. This page is mainly about Panax ginseng C.A.Mey. (Asian ginseng) and Panax quinquefolius L. (American ginseng). [2] Findings for one may not apply to the other, or to eleuthero; see ginseng types compared.

Warfarin and blood clotting

So the two studies point in different directions, which may reflect different plants, preparations or designs. NIH separately says Asian ginseng may interfere with blood clotting. [1] Proper evidence not found in the sources we read for the effect of ginseng on warfarin in people taking it long term. People on warfarin have blood tests (INR) arranged by their clinician; see supplements and blood thinners.

Blood sugar and diabetes medicines

• Label as documented: NIH says some evidence suggests Asian ginseng might lower blood sugar, and that people with diabetes should consult a provider first. [1]
• Pooled trials: a 2022 review of 20 trials in prediabetes and type 2 diabetes reported lower fasting glucose and insulin-resistance scores. [5] NIH, summarizing 2022 research, calls the evidence for improving blood sugar control in people with diabetes overall inconclusive and conflicting. [1]
• Type matters: in 12 healthy adults given 3 g of each of eight types before a glucose drink, Asian ginseng raised peak glucose while American and Vietnamese types tended to lower the 90-minute value. [6]
• With diabetes medicines: how much ginseng changes the effect of specific diabetes medicines: Proper evidence not found. We searched PubMed for ginseng with hypoglycemia and antidiabetic drugs and read NIH; nothing we read measured it. The theoretical concern is low blood sugar when two things that lower it are combined, so ask about supplements and diabetes medicines and blood pressure and sugar.

Sleep, nerves and mood

NIH says insomnia is the most common side effect. [1] A systematic review of case reports of mania linked to herbal medicines (excluding cannabis) found 35 reports across 11 products, five of them for Panax ginseng; the authors said causal attribution was problematic because reports were few, details were missing, and antidepressants were co-prescribed in 7 cases. [7] A separate paper described two men with mania after high-dose daily ginseng use that cleared within days of stopping; causation could not be determined. [8] These are reports, not measured risks. If you have bipolar disorder or a history of mania, talk to your prescriber. In the US, call 988 if you are in crisis.

How much is "safe"?

NIH says short-term oral use (up to 6 months) of Asian ginseng "in recommended amounts" appears safe for most people, but long-term safety questions have been raised. [1] The sources we read do not define a safe amount for an individual. Trial amounts ranged widely, for example 250 mg a day for four weeks [12] to 2000 mg a day for eight weeks. [13] These are study amounts, not advice. See also quality testing and certifications and the trial overview at ginseng for energy, fatigue and thinking.