L-Arginine — 500 mg, 100 Vegetarian Capsules — Supports Heart, Vascular & Circulatory Health*
LifeSource Vitamins L-Arginine (free-form) is a nitric-oxide precursor that supports healthy endothelial function, circulation, and exercise capacity.* Produced in FDA-registered, GMP-certified facilities and 3rd-party tested for identity, potency & purity. Non-GMO and gluten-free.*
Research-Driven & Verified Product.
Explore the clinical research, ingredient science, and global evidence supporting this product below.
Research Promise: At LifeSource Vitamins, our commitment is rooted in research and results. Every benefit below is supported by human clinical studies indexed in the National Institutes of Health (NIH) via PubMed, with full texts available in the National Library of Medicine (NLM) PubMed Central (PMC) when available. We also reference reviews from 39 leading health organizations and insights from 20 top global universities to keep our guidance aligned with credible, evidence-based science.* Every claim is supported by peer-reviewed human RCTs or meta-analyses whenever available.
Clinically Studied Benefits
✓ Supports endothelial function — Improves flow-mediated dilation (FMD) when baseline FMD is low.
NIH/PubMed — Bai Y, 2009
✓ Helps maintain healthy blood pressure — Meta-analysis of RCTs shows reductions in SBP/DBP.
NIH/PubMed — Li X, 2022
✓ Supports erectile function (vasculogenic, mild–moderate) — RCTs reported improvement vs placebo/no treatment.
NIH/PubMed — Sansone A, 2019
✓ Supports cognitive performance in older adults with hypertension — Improvement observed after oral L-arginine.
NIH/PMC — Izzo C, 2022
✓ Supports walking performance in exertional leg discomfort — Improved vascular reactivity and walking distance.
NIH/PubMed — Maxwell AJ, 2007
✓ Improves endothelial function in very old adults — Normalized L-arginine/ADMA ratio and enhanced dilation.
NIH/PubMed — Bode-Böger SM, 2003
✓ Supports wound-healing parameters with nutrition support — Improved outcomes when included in oral nutrition.
NIH/PubMed — Cereda E, 2019
✓ Supports immune function markers — Meta-analysis indicates favorable effects on selected immune outcomes.
NIH/PubMed — McDaniel JC, 2014
✓ Enhances NO-mediated vasodilation — Increased NO-dependent, flow-induced vasodilation.
NIH/PubMed — Böger RH, 1998
✓ Supports acute endothelial function in essential hypertension — Oral arginine improved endothelium-dependent dilation.
NIH/PMC — Nardin C, 2020
Additional / Promising Evidence
✓ May support exercise performance — NO-related ergogenic effects, results mixed.
NIH/PMC — Alvares TS, 2020
✓ May aid walking distance in short-term use — Select trials reported improvements.
NIH/PubMed — Böger RH, 1998
✓ May modulate arginine/NO pathway in recovery settings — With vitamin C.
NIH/PMC — Marzatico F, 2023
✓ Evidence for endurance outcomes remains inconsistent — Source, dose, training status matter.
NIH/PubMed — Santos RS, 2021
✓ May support cardiovascular recovery — Preliminary data.
Preliminary Data
✓ May enhance metabolic health — Early human studies.
Early Human Studies
University-Led & Academic Studies
✓ Supports endothelial function — L-Arginine improves flow-mediated dilation in subjects with low baseline FMD (academic clinical trial).
NIH/PubMed — Bai Y, 2009
✓ Helps maintain healthy blood pressure — Oral L-arginine supplementation reduces blood pressure in meta-analysis (university-affiliated research).
NIH/PubMed — Li X, 2022
✓ Supports erectile function — L-Arginine improves mild-moderate vasculogenic erectile dysfunction (academic RCTs).
NIH/PubMed — Sansone A, 2019
Global Evidence & Reviews
✓ Supports vascular & circulatory health — L-Arginine as nitric oxide precursor for endothelial function and blood pressure regulation.
NIH/ODS — L-Arginine Fact Sheet
✓ Helps maintain healthy blood pressure — Meta-analyses confirm modest reductions in systolic and diastolic pressure.
NIH/PubMed — Li X, 2022
✓ Supports endothelial-dependent vasodilation — L-Arginine enhances NO production and vascular health in reviews.
NIH/PubMed — Böger RH, 1998
We monitor research from leading institutions —
Harvard, Johns Hopkins, Mayo Clinic, Cleveland Clinic, Cambridge, Oxford, Stanford, Yale, Tufts, University of Florida, Oregon State University – Linus Pauling Institute, Columbia, Cornell, Ohio State — to align with credible science.*
Key Ingredients
- L-Arginine (free-form) — Nitric-oxide precursor that supports endothelium-dependent vasodilation and vascular health. (NIH/PMC — Nardin C, 2020)
Brief Benefit Bullets
- Supports heart & vascular health*
- Helps maintain healthy blood pressure*
- Supports healthy circulation & endothelial function*
- Nitric-oxide precursor for workout support*
- Pure, free-form amino acid*
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3rd-party lab tested for purity & potency
Suggested Use
See product label for full instructions, or as directed by your healthcare professional. Do not exceed recommended dose. If pregnant, nursing, taking medications, or have a medical condition, consult your physician.*
Product Specifications
- Serving Size — 2 Vegetarian Capsules
- Servings Per Container — 50
- Form — Vegetarian Capsules
- Free From — Non-GMO; not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree-nut ingredients*
- Quality — Third-party tested for identity, potency & purity
LifeSource Vitamins — Proudly American — Since 1992
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
L-Arginine 500 mg - nitric oxide precursor for heart & vascular health, circulation & healthy blood pressure. 3rd-party tested. Clinically Studied Ingredients — NIH/PubMed!*
