Homocitrulline is an amino acid that is produced in the body during the metabolism of arginine, an essential amino acid. It is formed through a reaction involving the enzyme arginase, which converts arginine into ornithine and urea. Homocitrulline can also be found in certain foods and is considered a non-protein amino acid. This compound plays a role in the urea cycle, which helps remove ammonia from the body. Elevated levels of homocitrulline may be associated with certain health conditions, including cardiovascular diseases and kidney disorders. However, more research is needed to fully understand its implications in human health.