NOW? Sports Pro-GH? is an amino acid supplement formulated to support optimal sports performance.* Pro-GH? has arginine, ornithine, lysine, and glutamine, which are critical for normal endocrine function and help to promote muscle tissue growth and recovery.* These same amino acids are also essential for the production and maintenance of nitric oxide (NO) within blood vessels, further supporting the body?s optimal response to intense physical training.* Glycine, known for its role in glycogen synthesis, has been included to support muscular energy output.* Finally, glutamine and glycine help to support healthy immune system responses, especially during times of physical stress and intense exercise.* NOW? Sports Pro-GH? thus combines the amino acids needed to help you attain your training goals into one convenient product.