What Meta-Analyses Tell Us: Ginseng Has Not Been Shown to Significantly Raise Blood Pressure
Following Siegel's report, numerous clinical trials were conducted using more rigorous scientific methods, including randomization, double-blinding, and placebo controls.
When the findings of these studies are considered together, they present a different picture from the concerns raised in 1979.
1. Komishon et al. (2016): Analysis of 17 Clinical Trials Involving 1,381 Participants
A research team associated with St. Michael's Hospital in Toronto reviewed 17 clinical trials lasting at least four weeks, drawing on four medical databases.
The analysis found no statistically significant increase in systolic blood pressure, diastolic blood pressure, or mean arterial pressure associated with ginseng consumption.
The researchers concluded that ginseng appeared to have a neutral effect on blood pressure and that concerns about blood pressure elevation alone did not justify discouraging its use.
Among participants with diabetes, metabolic syndrome, or obesity, the analysis also suggested a reduction in systolic blood pressure of approximately 2.76 mmHg, although such subgroup findings should be interpreted cautiously.
2. Lee et al. (2017): Analysis of Nine Trials Involving People With Hypertension or Prehypertension
A Korean research team conducted a systematic review and meta-analysis of nine double-blind clinical trials involving people with hypertension or prehypertension.
The analysis reported that Korean red ginseng was associated with the following reductions in blood pressure during acute administration:
- Systolic blood pressure: −6.52 mmHg
- Diastolic blood pressure: −5.21 mmHg
With longer-term administration over several weeks, the reported reductions were:
- Systolic blood pressure: −2.92 mmHg
- Diastolic blood pressure: −3.19 mmHg
The authors also reported an I² value of 0%, indicating little observed statistical heterogeneity among the studies included in the analysis.
These findings suggest a potential blood-pressure-lowering effect. However, the results do not establish that all ginseng products produce the same effects or that ginseng can replace prescribed hypertension medication.
3. A Large Meta-Analysis of 45 Clinical Trials Published in 2024
A systematic review and meta-analysis published in 2024 examined 45 clinical trials investigating ginseng consumption and cardiovascular health biomarkers.
The analysis reported a statistically significant reduction in systolic blood pressure of approximately 2.57 mmHg among participants consuming ginseng.
It also reported reductions in total cholesterol, LDL cholesterol, C-reactive protein, and interleukin-6.
The blood-pressure findings appeared more pronounced in studies involving consumption periods shorter than 12 weeks and among people with existing health risk factors.
These findings are promising, but the magnitude and clinical significance of the effects require careful interpretation.
4. Stavro et al. (2006): A 24-Hour Blood Pressure Study in 52 People With Hypertension
In a randomized, double-blind, crossover trial, 52 people with hypertension received 3 grams per day of North American ginseng over a 12-week study period.
The researchers used ambulatory blood pressure monitoring to measure blood pressure throughout normal daily activities.
The results showed no significant difference in blood pressure between the ginseng and placebo conditions. Kidney function was also unaffected.
This study provides additional evidence that the specific North American ginseng preparation tested did not significantly raise blood pressure or adversely affect kidney function under the study conditions.
The findings are consistent with the results of my own animal experiments at Seoul National University College of Medicine in 1996: neither ginseng extracts nor the diol- and triol-type ginsenosides tested produced significant changes in blood pressure.
In this case, findings from animal experiments and human clinical studies point in a broadly similar direction.
Can Ginseng Actually Help Lower Blood Pressure?
Research has investigated several biological mechanisms through which certain ginseng compounds may influence blood vessel function and blood pressure.
First: Ginsenoside Rg3 May Help Relax Blood Vessels
Ginsenoside Rg3 has been studied for its potential to promote the production of nitric oxide (NO) in vascular endothelial cells, which line the inside of blood vessels.
Nitric oxide helps relax the smooth muscles in blood vessel walls, allowing the vessels to widen and potentially lowering blood pressure.
Research suggests that Rg3 may influence this process through signaling pathways involving PI3K/Akt and estrogen receptors.
However, the strength of these effects can vary depending on the experimental conditions and the preparation being studied.
Second: Rg3 May Influence the Angiotensin-Converting Enzyme (ACE)
ACE, or angiotensin-converting enzyme, plays an important role in the renin-angiotensin system, which regulates blood pressure. It helps produce angiotensin II, a substance that constricts blood vessels.
Some experimental studies suggest that Rg3 may inhibit ACE activity, potentially reducing blood vessel constriction.
This mechanism resembles one of the ways ACE-inhibitor medications, such as enalapril and ramipril, help lower blood pressure.
In an animal study involving hypertensive rats, Rg3-enriched Korean red ginseng was associated with ACE-inhibitory activity after eight weeks of administration.
However, these experimental findings do not mean that ginseng works as effectively as prescription ACE inhibitors in humans.
Third: Ginseng Compounds May Help Protect Blood Vessel Structure
Long-standing hypertension can cause blood vessel walls to thicken and become less flexible.
Studies in hypertensive rats have investigated whether Rg3-enriched Korean red ginseng can reduce aortic wall thickness and cross-sectional area.
Nitric oxide may contribute to these effects by influencing the migration and proliferation of vascular smooth muscle cells.
Although these findings offer insight into possible protective mechanisms, further clinical research is needed to establish whether the same benefits occur in people.
Taken together, these mechanisms suggest that certain ginseng compounds may support healthy vascular function. Nevertheless, laboratory and animal findings should not be interpreted as proof that ginseng can prevent or treat hypertension.
Traditional Korean Herbal Medicine Does Not Describe Ginseng as a Blood-Pressure-Raising Herb
Traditional Korean materia medica describes ginseng as sweet in taste and slightly warm in nature. One of its best-known traditional functions is expressed by the phrase daebo wonqi, meaning to strongly replenish the body's vital energy.
This traditional concept concerns the restoration and support of the body's overall functional state. It does not correspond directly to the modern medical concept of raising blood pressure.
In the Donguibogam, a classic Korean medical text, ginseng is described as helping generate body fluids, relieve thirst, and address patterns of deficiency. These traditional descriptions should be understood within their historical medical framework rather than treated as direct evidence of modern physiological effects.
From the perspective of traditional herbal medicine, ginseng is sometimes discussed in connection with the concept of an adaptogen, a substance thought to help the body respond to physical or environmental stress.
However, the popular claim that ginseng always lowers high blood pressure and raises low blood pressure is not firmly established by clinical evidence.
The traditional description of ginseng and modern research into its physiological effects represent different approaches to understanding the herb. Neither should be used to make claims that go beyond the available evidence.
Summary: What Does the Evidence Say About Ginseng and Hypertension?
| Evidence | Main Findings |
|---|---|
| 1979 report | Described possible adverse effects associated with prolonged ginseng use but had no control group and could not establish causation. |
| 1996 animal experiments | The author's experiments involving hundreds of rats found no statistically significant blood-pressure changes from the tested ginseng extracts and ginsenosides. |
| 2016 meta-analysis: 17 trials, 1,381 participants | Found no significant increase in systolic, diastolic, or mean arterial pressure. |
| 2017 meta-analysis: 9 trials | Reported potential blood-pressure reductions associated with Korean red ginseng in people with hypertension or prehypertension. |
| 2024 meta-analysis: 45 trials | Reported an average systolic blood-pressure reduction of approximately 2.57 mmHg. |
| Proposed mechanisms | Rg3 may influence nitric oxide production, ACE activity, and vascular function; further human research is needed. |
The Bottom Line
The available clinical evidence does not support the blanket claim that ginseng inevitably raises blood pressure.
Several clinical trials and meta-analyses have found no significant blood-pressure increase, while some have reported modest reductions. However, results vary among studies, and the effects depend on the ginseng preparation, dosage, duration of use, and individual health factors.
People with hypertension should not automatically assume that all ginseng products are unsafe. However, ginseng should not be used as a substitute for prescribed blood-pressure medication.
If you have severe or uncontrolled hypertension, take antihypertensive medication, or have other medical conditions, consult your healthcare professional before using ginseng regularly. Ginseng may also interact with certain medications, so individualized medical advice is important.
The key lesson is that health decisions should be based on the totality of scientific evidence rather than a single historical report.
References
- Siegel RK. Ginseng abuse syndrome: Problems with the panacea. JAMA. 1979;241(15):1614–1615.
- Komishon AM, Shishtar E, Ha V, et al. The effect of ginseng (genus Panax) on blood pressure: A systematic review and meta-analysis of randomized controlled clinical trials. Journal of Human Hypertension. 2016;30(10):619–626.
- Lee HW, Lim HJ, Jun JH, et al. Ginseng for treating hypertension: A systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials. Current Vascular Pharmacology. 2017;15(6):549–556.
- Effects of ginseng consumption on cardiovascular health biomarkers in adults: A systematic review and meta-analysis of randomized controlled trials. 2024.
- Stavro PM, Woo M, Leiter LA, et al. Long-term intake of North American ginseng has no effect on 24-hour blood pressure and renal function. Hypertension. 2006;47(4):791–796.
- Lee S, et al. Antihypertensive effect of Korean red ginseng by enrichment of ginsenoside Rg3 and arginine-fructose. Journal of Ginseng Research. 2016;40(3):237–244.
- Nagar H, et al. Rg3-enriched Korean red ginseng enhances blood pressure stability in spontaneously hypertensive rats. Integrative Medicine Research. 2016;5(3):223–229.
- Kim ND, et al. Ginsenoside Rg3 increases nitric oxide production via increases in phosphorylation and expression of endothelial nitric oxide synthase. Toxicology and Applied Pharmacology. 2010;246(3):133–140.
- Park SH, Chung S, Chung MY, et al. Effects of Panax ginseng on hyperglycemia, hypertension, and hyperlipidemia: A systematic review and meta-analysis. Journal of Ginseng Research. 2022;46(2):188–205.
Author: Ho-Cheol Kim, Professor of Herbal Pharmacology, College of Korean Medicine, Kyung Hee University; CEO of Neumed Co., Ltd.
