L-Citrulline, 100g Pwd by Allergy Research GroupL citrulline, like L arginine and L ornithine, is involved in the metabolism of ammonia waste in the urea cycle, and in the vasodilation pathways. Carbamoyl phosphate is converted to citrulline in the ornithine carbamoyltransferase reaction, and when endogenous supplies of ornithine carbamoyltransferase are insufficient, supplemental L citrulline may be useful. Free form amino acid, high purity, well tolerated. These statements have not been evaluated