From the Research
L-citrulline does not have a Nobel Prize-winning formula for lowering blood pressure, but it may help reduce blood pressure by converting to l-arginine in the body, which then produces nitric oxide to relax blood vessels. For those interested in using l-citrulline for blood pressure management, typical dosages range from 3-6 grams daily, with some studies suggesting benefits at doses of 6-8 grams per day 1, 2. The supplement works by increasing nitric oxide production, which dilates blood vessels and improves blood flow. Effects are generally modest, with potential reductions of 4-15 mmHg in systolic blood pressure, as seen in a systematic review and meta-analysis of randomized controlled trials 1.
Key Points to Consider
- L-citrulline is available in powder or capsule form and is generally well-tolerated, though it should not replace prescribed blood pressure medications.
- Always consult with a healthcare provider before starting any supplement, especially if you have existing health conditions or take other medications.
- A recent study found that short-term L-citrulline supplementation did not affect blood pressure, pulse wave reflection, or arterial stiffness at rest and during isometric exercise in older males 3.
- However, another study suggested that L-citrulline supplementation may reduce systolic blood pressure, particularly in pre-hypertensive and hypertensive populations, with significant improvements seen in study durations of ≥6 weeks, lower doses of ≤4 g/day, and in participants with higher baseline values of ≥130/85 mmHg 1.
Important Considerations
- The evidence for L-citrulline's effect on blood pressure is not uniform, and more research is needed to fully understand its potential benefits and limitations.
- L-citrulline may be more efficacious in certain populations, such as pre-hypertensive and hypertensive individuals, and may have sex-dependent effects, with some studies suggesting benefits in women but not men 4.