NutriStack
Hydrochlorothiazide and L-Citrulline, a caution.
L-Citrulline can increase arginine availability and modestly lower systolic blood pressure. Hydrochlorothiazide also lowers blood pressure, so the combination may cause lightheadedness or readings below your usual range. Risk is higher with dehydration, low sodium intake, older age, or multiple antihypertensive medications.
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
- Hydrochlorothiazide and L-Citrulline
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 2 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 can increase arginine availability and modestly lower systolic blood pressure. Hydrochlorothiazide also lowers blood pressure, so the combination may cause lightheadedness or readings below your usual range. Risk is higher with dehydration, low sodium intake, older age, or multiple antihypertensive medications.
Mechanism. L-Citrulline is converted to L-arginine and supports nitric oxide production, causing vasodilation. Hydrochlorothiazide lowers blood pressure through sodium loss and vascular effects, making additive hypotension possible.
Recommendation. If you add L-Citrulline while taking hydrochlorothiazide, start with a low dose and track blood pressure for 1-2 weeks. Reduce or stop it if you develop dizziness, fainting, or unusually low readings.
Sources (2)
- Barkhidarian B, Khorshidi M, Shab-Bidar S, Hashemi B. Effects of L-citrulline supplementation on blood pressure: A systematic review and meta-analysis. Avicenna J Phytomed. 2019;9(1):10-20. PMID 30788274
- Sica DA. Diuretic-related side effects: development and treatment. J Clin Hypertens (Greenwich). 2004;6(9):532-540. PMID 15365284
Stack Score
How this pair moves the number.
Effect on the composite score
If both Hydrochlorothiazide and L-Citrulline 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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