L-Citrulline is a non-essential amino acid. The kidneys convert L-citrulline to L-arginine, another amino acid which increases the production of nitric oxide. These are important as they can aid in heart health and immunity. L-citrulline is more commonly supplemented in a bid to increase nitric oxide booster, which allows the arteries to relax and increase blood flow throughout the body. This allows greater muscle pumps to be achieved, as more blood, oxygen and nutrients are able to enter working muscle groups. Some foods naturally produce L-Citrulline such as watermelons. L-Citrulline has also been shown to improve overall athletic performance in healthy individuals.