L-Arginine
Plain-language research summary.
Detail
circulationheartperformancenitric-oxide
Amino acid and nitric-oxide precursor studied for endothelial function, circulation, and exercise performance in select contexts.
Common Dietary Sources
- Protein foods (meat, poultry, fish), nuts/seeds, legumes
How the Body Uses It
Arginine is a substrate for nitric oxide synthase (NOS) to produce nitric oxide (NO), a key mediator of vasodilation and endothelial function.
Supplement Origins
Supplements typically provide free-form L-arginine or arginine salts.
Possible Uses
- Endothelial function / circulation support
- Exercise performance (select contexts)
- Adjunct blood-pressure support (with clinician oversight)
Long-Term Use
Generally well tolerated short-term; GI upset possible at higher doses. Longer-term use should be individualized and monitored in cardiovascular conditions.
Dose Guidance
Studied
3–6 g/day, often divided; sports protocols vary
Start low and split doses to improve tolerance.
Forms
L-Arginine (free form)
Standardization varies by product.
Arginine salts (e.g., arginine HCl)
Standardization varies by product.
Delivery
Capsule
Powder
Mix with water/juice; larger single doses may cause GI upset.
Evidence & Studies
No studies linked yet.
References
Safety & Cautions
Cautions
- GI upset (nausea, cramps, diarrhea) at higher intakes
- May worsen symptoms in active herpes infections (theoretical)
Contraindications
- Recent myocardial infarction (avoid unless directed by clinician)
- Severe hypotension
Interactions
- May have additive effects with antihypertensives and PDE-5 inhibitors