citrulline

Citrulline is a non-essential α-amino acid naturally found in watermelon and produced in the body as part of the urea cycle. It is not incorporated into proteins but serves as a precursor to arginine and nitric oxide (NO), both of which are important for cardiovascular health. Citrulline supplementation increases plasma arginine levels more effectively than direct arginine supplementation due to better absorption and metabolism. Its main mechanisms include enhancing NO production (leading to vasodilation and improved blood flow), supporting muscle protein synthesis under catabolic conditions, exhibiting antioxidant and anti-inflammatory effects by modulating oxidative stress pathways such as NF-κB, aiding ammonia detoxification via the urea cycle, and serving as a biomarker for intestinal function. Clinically and nutraceutically it has been used or studied for athletic performance enhancement, erectile dysfunction (ED), hypertension (including pulmonary hypertension), sickle cell disease symptoms relief, heart disease support, fatigue reduction in various conditions including dementia/Alzheimer’s disease[1][2][3][4][5][6][7].

Brand names

citrulline HCl

Other names

2-amino-5-(carbamoylamino)pentanoic acidCitrulline MalateL-CitrulinaL-Citrulline AKGL-Citrulline-Alpha Ketoglutaric AcidL-Citrulline MalateMalate de Citrulline