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

Eur J Nutr. 2019 Apr;58(3):1237-1245. doi: 10.1007/s00394-018-1642-0. Epub 2018 Feb 24.


Purpose: Despite the lack of evidence, a growing number of people are using herbal medicine to attenuate the burden of diabetes. There is an urgent need to investigate the clinical potential of herbs. Preliminary observations suggest that American ginseng (Panax quinquefolius [AG]) may reduce postprandial glycemia. Thus, we aimed to evaluate the efficacy and safety of AG as an add-on therapy in individuals with type 2 diabetes (T2DM) controlled by conventional treatment.

Methods: 24 individuals living with T2DM completed the study (F:M = 11:13; age = 64 ± 7 year; BMI = 27.8 ± 4.6 kg/m2; HbA1c = 7.1 ± 1.2%). Utilizing a double-blind, cross-over design, the participants were randomized to receive either 1 g/meal (3 g/day) of AG extract or placebo for 8 weeks while maintaining their original treatment. Following a ≥ 4-week washout period, the participants were crossed over to the opposite 8-week treatment arm. The primary objective was HbA1c, and secondary endpoints included fasting blood glucose and insulin, blood pressure, plasma lipids, serum nitrates/nitrites (NOx), and plasominogen-activating factor-1 (PAI-1). Safety parameters included liver and kidney function.

Results: Compared to placebo, AG significantly reduced HbA1c (- 0.29%; p = 0.041) and fasting blood glucose (- 0.71 mmol/L; p = 0.008). Furthermore, AG lowered systolic blood pressure (- 5.6 ± 2.7 mmHg; p < 0.001), increased NOx (+ 1.85 ± 2.13 µmol/L; p < 0.03), and produced a mean percent end-difference of - 12.3 ± 3.9% in LDL-C and - 13.9 ± 5.8% in LDL-C/HDL. The safety profiles were unaffected.

Conclusions: AG extract added to conventional treatment provided an effective and safe adjunct in the management of T2DM. Larger studies using physiologically standardized ginseng preparations are warranted to substantiate the present findings and to demonstrate therapeutic effectiveness of AG. CLINICALTRIALS.

Gov identifier: NCT02923453.

Keywords: Blood glucose; Blood pressure; Cholesterol; Diabetes mellitus; Ginseng; Panax quinquefolius.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Blood Glucose / drug effects*
  • Cardiovascular Diseases / prevention & control*
  • Cross-Over Studies
  • Diabetes Mellitus, Type 2 / metabolism*
  • Double-Blind Method
  • Female
  • Humans
  • Hypoglycemic Agents / adverse effects
  • Hypoglycemic Agents / pharmacology*
  • Insulin / blood
  • Male
  • Middle Aged
  • Panax*
  • Plant Extracts / adverse effects
  • Plant Extracts / pharmacology*
  • Risk Factors
  • Treatment Outcome


  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin
  • Plant Extracts

Associated data

  • ClinicalTrials.gov/NCT02923453