L-citrulline

L-citrulline is a non-essential (conditionally essential) amino acid that the body cannot produce in sufficient quantities, especially during intense physical exertion, so it needs to be supplemented through dietary protein. While it is not a constituent of most proteins in the body, citrulline is found in special proteins of hair, skin, and nerve cells. It is primarily synthesized from glutamine in the intestines, but it is also naturally present in some foods, such as watermelons.

Citrulline balances nitrogen levels and metabolic processes and forms the basis for the production of the amino acids L-arginine and L-ornithine, which are very popular among athletes. Citrulline plays a vital role in the dilation of blood vessels - after citrulline is ingested, a significant portion is converted into arginine, which is further transformed into nitric oxide. Nitric oxide relaxes the muscles surrounding blood vessels, causing them to expand. This results in improved oxygen and nutrient supply to muscles and the removal of harmful substances. The dilation of blood vessels also simultaneously reduces blood pressure, which is another benefit of taking citrulline.

Citrulline enhances aerobic performance and working capacity by affecting lactic acid to reduce fatigue. Studies show reduced mental and muscular fatigue and exhaustion in postoperative patients, and it can lead to improved performance in athletes.