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.
Starting dose. 3-6g — Daily, divided
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.
L-Arginine is the substrate for nitric oxide synthase:
NOS enzymes (eNOS, iNOS, nNOS) convert L-Arginine + O2 → L-Citrulline + NO. NO is a potent vasodilator that relaxes vascular smooth muscle.
NO drives endothelium-dependent vasodilation, improving blood flow, lowering blood pressure modestly, and supporting endothelial function.
NO is the primary mediator of penile erection (corporal smooth muscle relaxation).
Arginine is required for collagen synthesis and immune function during wound healing.
~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.
Oral arginine plasma levels peak quickly and fall - sustained NO support requires frequent dosing or L-Citrulline alternative.
Pre-workout: acute pump effect.
Weeks: cardiovascular markers improve.
Long-term: sustained effects with continued use.
Each reference below was re-fetched from its PubMed record, and the quoted sentence was confirmed to appear in that abstract and to support the claim it sits under. Follow any of them to read the source.
Evidence boundary from the checked abstract: L-arginine therapy showed promise in treating stroke-like episodes in MELAS.
L-arginine therapy showed promise in treating stroke-like episodes in MELAS.
Evidence scope. This entry supports only the exact statement quoted from the live abstract; it does not independently verify OnePin's displayed dose, route, frequency, formulation, population, or broader mechanism.
Claims we could not support
No abstract we checked supports these for this molecule at this route. That is not the same as saying they are false — it marks where the evidence is missing.
Dose/route: 3-6g daily, divided; Oral capsule or powder; 1-3x daily. No checked live PubMed abstract verified this exact displayed dose, route, and frequency for the same molecule/formulation and relevant population.
Primary safety claim: No primary safety text present in source JSON. No checked live PubMed abstract directly verified this source-JSON safety claim at the displayed formulation, route, and regimen.
Plasma
Post-ingestion
Hours plasma
Oral ~30-50% (intestinal arginase metabolism)
Pulse plasma elevation; sustained effect requires divided dosing
Hepatic and tissue
Storage. Powder/capsule. Cool dry location.
Dietary supplement (US, DSHEA).
Put it to work
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 complete L-Arginine walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
Join the community ↗Track it in OnePin. Log vials, draws, and protocols in the app.
Type a name, brand, or tool. Esc closes.