You can obtain Citrulline from food, especially watermelons, and it can be also manufactured from ornithine, in the body’s urea cycle. This cycle helps rid your body of ammonia, a waste product of protein digestion.
After your digestive system metabolizes citrulline malate into citrulline, enzymes in your liver cells convert it into arginine, then into nitric oxide in a process that also produces new citrulline molecules. Nitric oxide is well known for its function as a vasodilator. Supplementing L-citrulline also increases ornithine and arginine plasma content.
L-arginine and L-ornithine are subject to reduced absorption when supplemented in doses of 10g or more, which can result in diarrohea. L-Citrulline does not have this side-effect, and since it increases plasma levels of all three amino acids, it may be the preferred as a supplement over L-arginine. L-citrulline doubles ornithine plasma content.
As a dietary supplement take 2 teaspoon between meals. May be taken with your favourite fruit or vegetable juice or as part of pre-workout routine.