✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full L-Arginine evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Citrulline > arginine for NO production [1]
⚠ PDE5 inhibitors + arginine = dangerous hypotension [1]
⚠ Nitrates + arginine = dangerous hypotension [1]
ℹ️ Not obtained from food. Not applicable as a daily target — obtained as part of dietary protein rather than tracked individually.
🔬 Lab interpreter
Recommended test
Blood pressure
Blood pressure
Reference range / target
Reduction if hypertensive
Reduction if hypertensive
~5 mmHg SBP [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Some preeclampsia prevention trials. Generally safe [2].
👦 Pediatric: See guidance
IV arginine stimulation test for GH deficiency [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: Divided doses [2].
💊 With food: Empty stomach for best absorption [1].
🚫 Avoid: PDE5 inhibitors. Nitrates [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['L-Arginine HCl', 'common', 'Standard. 3–6 g/day [1].'] | Standard | Check label | |
| ['L-Arginine alpha-ketoglutarate (AAKG)', '', 'Pre-workout marketing. No proven advantage over plain arginine [1].'] | Standard | Check label | |
| ['L-Citrulline (preferred alternative)', 'preferred', 'See Citrulline Malate entry — more effective NO precursor [1].'] | Standard | Check label |
3 Common questions
Should I take arginine or citrulline? ▼
Citrulline — it raises plasma arginine 2× more effectively because it bypasses liver arginase. Unless you have a specific reason for arginine (some clinical trials used it), citrulline is the better NO precursor [1].
4 Clinical evidence
Strong
Arginine → NO via NOS: established biochemistry [1]. Hepatic arginase degrades ~40% of oral arginine: confirmed PK [1]. Citrulline raises plasma arginine more effectively: confirmed in direct comparison [1]. HIGH
Moderate
Blood pressure: meta-analysis of 11 RCTs — modest SBP reduction (~5 mmHg) [2]. Erectile dysfunction: some trials positive at 5 g/day (via NO → vasodilation) but less effective than PDE5 inhibitors [2]. Preeclampsia prevention: some trials positive for arginine + antioxidants [2]. Intermittent claudication: some evidence for improved walking distance [2]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Recent (acute) myocardial infarction — associated with worse outcomes in a clinical trial
✕ Concurrent nitrates or PDE-5 inhibitors — additive hypotension
Relative
⚠ Active herpes (HSV) — arginine may promote viral replication
⚠ Antihypertensives — additive effect
⚠ Asthma — caution
🚩 Red flags
● PDE5 inhibitor + arginine — hypotension [1]
● Nitrate + arginine — severe hypotension [1]
6 Interactions
Drug interactions
PDE5 inhibitors Major
Mechanism: Additive NO vasodilation. [1]
Effect: Hypotension, syncope. [1]
Action: AVOID [1].
Supplement synergies
Switch to L-Citrulline · 3–6 g citrulline
More effective NO precursor [1].
More effective NO precursor [1].
7 Regulatory
United States: GRAS. Dietary supplement [1].
8 US supplement products
22
on-market products containing L-Arginine (NIH DSLD)
Brands carrying L-Arginine (7)
Click a brand to see its L-Arginine products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. L-Arginine — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Jul 15]. Available from: https://supplement.ge/ingredients/l-arginine/
APA 7th: Pkhakadze, G. (2026). L-Arginine — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/l-arginine/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: January 2027
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "L-Arginine — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/l-arginine/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG