OnePin Peptide Library · Performance
L-Arginine
L-Arginine HCl · Arginine
L-Arginine is a semi-essential amino acid that serves as the substrate for nitric oxide (NO) synthase. NO is a potent vasodilator and signaling molecule. L-Arginine supplementation aims to elevate NO production for cardiovascular benefits, exercise performance, and erectile function support.
Pre-workout or split doses.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
L-Arginine is the substrate for nitric oxide synthase:
NO Production
NOS enzymes (eNOS, iNOS, nNOS) convert L-Arginine + O2 → L-Citrulline + NO. NO is a potent vasodilator that relaxes vascular smooth muscle.
Cardiovascular Effects
NO drives endothelium-dependent vasodilation, improving blood flow, lowering blood pressure modestly, and supporting endothelial function.
Erectile Function
NO is the primary mediator of penile erection (corporal smooth muscle relaxation).
Wound Healing
Arginine is required for collagen synthesis and immune function during wound healing.
Bioavailability Limitation
~40% of oral L-Arginine is metabolized by intestinal arginase to ornithine before systemic absorption. Plasma levels rise less than expected from dose. L-Citrulline supplementation produces higher plasma arginine levels than equimolar L-Arginine.
Pulse-Dosing Issue
Oral arginine plasma levels peak quickly and fall - sustained NO support requires frequent dosing or L-Citrulline alternative.
What to expect
Pre-workout: acute pump effect.
Weeks: cardiovascular markers improve.
Long-term: sustained effects with continued use.
Evidence
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Keep separate
Side effects & safety
Commonly reported
- GI upset (bloating, nausea, diarrhea) - dose-limiting
- Mild headache
Less common & notes
- HSV reactivation in susceptible users (arginine/lysine ratio).
- Possible mortality concern in acute post-MI from older studies.
- Allergic reactions rare.
Pharmacokinetics
Storage. Powder/capsule. Cool dry location.
Regulatory status
Dietary supplement (US, DSHEA).
Put it to work
Calculate, log & track
Open L-Arginine straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
Open L-Arginine in the app →Go deeper
The guide & community
The complete L-Arginine walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
Join the community ↗