Tongkat Ali (Eurycoma longifolia) is a traditional herbal remedy native to Southeast Asia, used for centuries to address various health concerns, including fevers, fatigue, and sexual dysfunction. The root has gained global attention as a dietary supplement, often promoted for vitality and hormonal balance. Given the herb’s properties, individuals frequently ask about its influence on cardiovascular health, specifically its effect on blood pressure. Examining the available scientific data, including indirect biological mechanisms and the results from human trials, provides a clearer picture of its role in blood pressure regulation.
Biochemical Pathways Relevant to Blood Pressure Regulation
Tongkat Ali’s potential to influence blood pressure is linked to its adaptogenic properties and modulation of the body’s stress response system. The herb contains bioactive compounds, notably quassinoids, that interact with the hypothalamic-pituitary-adrenal (HPA) axis, the central system for managing stress. Chronic stress causes the HPA axis to remain highly active, leading to the sustained overproduction of the stress hormone cortisol.
The persistent elevation of cortisol is a known contributor to hypertension, or high blood pressure. Cortisol increases vascular tone and sensitivity to vasoconstrictive agents, narrowing blood vessels and raising the pressure required to circulate blood. By modulating the HPA axis, Tongkat Ali supplementation has been shown in human studies to significantly reduce salivary cortisol levels, with reductions reported around 16% in stressed individuals over four weeks.
This reduction in stress hormone exposure suggests a potential indirect mechanism for blood pressure maintenance. Laboratory research also indicates that Tongkat Ali extract may possess vasorelaxation properties and inhibit angiotensin-converting enzyme (ACE) activity. This inhibition is similar to the action of prescription blood pressure medications, suggesting a possible direct effect on vascular function by helping blood vessels relax and widen.
Clinical Findings on Tongkat Ali and Blood Pressure
Direct human clinical trials specifically designed to measure Tongkat Ali’s effect on blood pressure are limited, as most studies focus on its influence on testosterone, stress, and athletic performance. However, in these trials, where blood pressure is often measured as a secondary outcome, the evidence generally suggests a neutral or mildly beneficial effect. Across multiple studies examining the herb, there have been no significant reports of blood pressure increases as an adverse effect in healthy individuals.
One randomized, controlled study noted that participants taking Tongkat Ali experienced a slight decrease in diastolic blood pressure after six weeks of supplementation. This observation aligns with the theoretical benefit derived from its stress-reducing and vascular-relaxing mechanisms. The overall consensus from human data is that Tongkat Ali does not appear to raise blood pressure in normotensive populations when taken at standard dosages.
The most compelling evidence for a blood pressure-lowering effect comes from animal studies involving hypertensive models. In rats bred for high blood pressure, Tongkat Ali extract produced significant reductions in both systolic and diastolic blood pressure. This effect was only observed in the hypertensive animals, suggesting the herb may have a normalizing action, lowering pressure when it is elevated but not affecting healthy levels.
While these animal findings are promising, they do not directly translate to human response, and more dedicated research is needed to confirm a reliable blood pressure-lowering effect in people with clinical hypertension. A small percentage of participants in some human trials have reported an increase in blood pressure as a side effect, which underscores the need for caution. The current scientific picture suggests that any potential benefit to blood pressure is likely a secondary effect of its adaptogenic and cortisol-modulating properties.
Guidelines for Supplementation and Drug Interactions
For individuals considering Tongkat Ali supplementation, the recommended daily dosage typically ranges from 200 mg to 400 mg of a standardized extract. It is important to look for products standardized to active compounds, such as eurycomanone, and to ensure the supplement has undergone third-party testing to verify purity and prevent contamination by heavy metals.
The use of Tongkat Ali alongside prescription medications, especially those for cardiovascular conditions, requires careful medical supervision due to the risk of drug interactions. Individuals taking antihypertensive medications, such as beta-blockers, should be cautious. Limited clinical data suggest that Tongkat Ali may interfere with the absorption of certain blood pressure drugs, such as propranolol, potentially reducing their effectiveness.
Because Tongkat Ali may exhibit mild vasorelaxation or ACE-inhibiting properties, there is a theoretical risk of additive hypotensive effects when combined with prescription antihypertensives. This could lead to blood pressure dropping too low, a condition known as hypotension. People with pre-existing cardiovascular conditions, diabetes, or those on anticoagulants should consult a healthcare provider before starting the supplement.