L-Arginine hydrochloride (Arg HCl)

L-Arginine hydrochloride is the hydrochloric acid salt of the semi-essential amino acid L-arginine, which plays a pivotal role in several physiological systems. It is primarily recognized as the sole substrate for Nitric Oxide Synthase (NOS), the enzyme family responsible for the production of nitric oxide (NO), a critical gasotransmitter that regulates vasodilation and endothelial health (PubChem, 2024). Beyond its vascular roles, L-arginine is an essential component of the urea cycle, where it helps convert toxic ammonia into urea for excretion (StatPearls, 2023). Clinically, the hydrochloride salt form is used as a diagnostic agent to evaluate growth hormone reserve by stimulating the pituitary gland, and it is also indicated for the treatment of severe metabolic alkalosis and certain hyperammonemic states (NIH, 2023). Because L-arginine hydrochloride is a metabolic precursor and chemical compound rather than a biological macromolecule like a receptor or enzyme, it is classified as a drug substance or substrate rather than a therapeutic target (DrugBank, 2024). It is often administered intravenously or orally to modulate endocrine signaling or correct metabolic imbalances.

Other names

Arginine hydrochlorideL-Arginine monohydrochlorideArginine chlorhydrate(S)-2-Amino-5-guanidinopentanoic acid hydrochloride

L-Arginine hydrochloride acts as a metabolic substrate for Nitric Oxide Synthase (NOS) to produce nitric oxide (NO), serves as an intermediate in the urea cycle to facilitate ammonia detoxification, and acts as a secretagogue to stimulate the release of growth hormone and insulin.