L-arginine is involved in many body activities, including ammonia detoxification, hormone secretion and immune modulation. Arginine is also well known as a precursor of nitric oxide (NO), a component that delivers messages between body cells and partly controls the blood circulation. As a result, when nitric oxide is synthesised by L-arginine, the arterial system is able to retain its youthful elasticity. At the same time, the immune system becomes stronger and Arginine also helps in maintaining your bones and tissues healthy. L-ornithine, a metabolite of arginine may contribute for the latter purpose too.
Some studies suggest that arginine and ornithine stimulate growth hormone (GH) evidenced by an increase in muscle strength during intense workouts. Other studies show the same effect for Ornithine alone. Some studies confirm that a combination of ornithine with acetyl-L-carnitine enhanced the GH release, while a low dose of the given combination is insignificant. The minimum dose required seems to be 5-9 grams.