NutriStack
L-Citrulline and Nitroglycerin, a caution.
L-citrulline raises circulating L-arginine and can support nitric-oxide-mediated blood pressure lowering. Nitroglycerin also works through nitric oxide signaling and can cause rapid drops in blood pressure. Combining them may increase headache, flushing, dizziness, or fainting risk, particularly in people with low baseline blood pressure or multiple antihypertensives.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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At a glance
- Substances
- L-Citrulline and Nitroglycerin
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. L-citrulline raises circulating L-arginine and can support nitric-oxide-mediated blood pressure lowering. Nitroglycerin also works through nitric oxide signaling and can cause rapid drops in blood pressure. Combining them may increase headache, flushing, dizziness, or fainting risk, particularly in people with low baseline blood pressure or multiple antihypertensives.
Mechanism. L-citrulline is converted to L-arginine, increasing substrate availability for nitric oxide synthase. Nitroglycerin donates nitric oxide and activates soluble guanylate cyclase, so the combined effect can increase cGMP-mediated vasodilation.
Recommendation. Avoid starting high-dose L-citrulline on your own if you use nitroglycerin. If your prescriber approves it, start low, monitor blood pressure, and stop the supplement if nitroglycerin causes more dizziness, faintness, or unusually low readings.
Sources (3)
- Tahvanainen A, Leskinen M, Koskela J, et al. Non-invasive measurement of the haemodynamic effects of inhaled salbutamol, intravenous L-arginine and sublingual nitroglycerin. Br J Clin Pharmacol. 2009;68(1):23-33. PMID 19660000
- Schwedhelm E, Maas R, Freese R, et al. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism. Br J Clin Pharmacol. 2008;65(1):51-59. PMID 17662090
- Mirenayat MS, Moradi S, Mohammadi H, Rouhani MH. Effect of L-Citrulline Supplementation on Blood Pressure: a Systematic Review and Meta-Analysis of Clinical Trials. Curr Hypertens Rep. 2018;20(11):98. PMID 30284051
Stack Score
How this pair moves the number.
Effect on the composite score
If both L-Citrulline and Nitroglycerin are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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