L-Arginine and Blood Pressure: Evidence, Usage, and Safety
Reading time: 9–12 minutes • Educational only.
Why L-arginine?
L-arginine is a substrate for nitric oxide synthase; by supporting nitric oxide (NO) production, it may influence endothelial function and vessel tone.
What the research suggests (human data)
- Dose-response meta-analysis (2022): pooled effect SBP −6.40 mmHg and DBP −2.64 mmHg; nonlinear dose response with ≥4 g/day associated with benefit.
- Earlier reviews report similar BP-lowering signals but highlight study heterogeneity.
Takeaway: Effects are small–modest on average; use as an adjunct to core habits and prescribed care.
How people typically use it (study-aligned)
- Dose: about 4–6 g/day total, split 2–3 times daily, for 2–8+ weeks; higher doses have not shown greater benefit.
- Compare with L-citrulline: some prefer citrulline for NO support; see our citrulline guide.
- Track a 7-day average before and after 2–4 weeks: How to Measure & Track.
Safety & interactions
- Additive BP-lowering: may enhance effects of antihypertensives/vasodilators and PDE-5 inhibitors (e.g., tadalafil); monitor for dizziness and coordinate with your clinician.
- Nitrates: avoid unsupervised combinations (e.g., nitroglycerin) due to hypotension risk.
- Recent heart attack: avoid unless your cardiologist recommends (VINTAGE-MI trial signaled potential harm).
- Herpes-family viruses: in vitro/case-level literature suggests high arginine may facilitate reactivation; those with recurrent outbreaks may prefer alternatives.
- Typical side effects: GI upset, cramps, headache—discontinue and seek care if unwell.
Pair with fundamentals
Educational Disclaimer: This article is for educational purposes only and is not medical advice.
References
- Shiraseb F, et al. L-arginine & BP — dose-response meta-analysis. Adv Nutr ; PMC.
- McRae MP. Umbrella review on L-arginine. J Chiropr Med.
- Drug-interaction resources — PDE-5 inhibitors/vasodilators, nitrates. Drugs.com ; Drugs.com.
- Post-MI caution — VINTAGE-MI randomized trial. JAMA.
- Herpes-reactivation context (precautionary). PMC ; PMC ; MDPI.
