Now L-Ornithine (500mg) 120 caps is a Ornithine dietary supplement. Ornithine is a non-essential amino acid that contributes mainly to supporting the process of the urea cycle. It works with Arginine and Citrulline to help the body remove ammonia, which is a harmful gas that contributes to brain and liver diseases. Since Ornithine converts to Arginine, it helps maintain healthy levels of Arginine in the body. It can also converts to other essential amino acids like proline, glutamate, Citrulline, and Creatine, a vital amino acid for muscle strength.