L-arginine is a proteinogenic amino acid that is part of proteins. It is considered a semi-essential amino acid, meaning that the body can produce it, but not in sufficient quantities. Therefore, proper supplementation through diet or L-arginine-based products is necessary. L-arginine serves multiple functions within the body. It is involved in the production of nitric oxide, and the nitrogen content of this amino acid is comparatively high. Although the body contains only a small amount of nitric oxide, it plays a significant role. Nitric oxide promotes blood circulation, reduces the risk of cell proliferation, and also protects against harmful microorganisms. This amino acid is also effective in combating erectile dysfunction as it improves blood flow in the vessels. Additionally, L-arginine can also protect against a heart attack, as it promotes the widening of arteries and thus better blood circulation, resulting in an increased cardiac output. Studies have also shown that L-arginine can reduce insulin resistance. Finally, L-arginine promotes the production of white blood cells and thereby automatically strengthens the immune system. Athletic performance can be improved with sufficient intake of L-arginine, as this amino acid promotes the release of growth hormones. Fat burning is also stimulated, and muscle mass can develop better. Muscle cells are also better supplied with nutrients thanks to L-arginine. Therefore, L-arginine-based products are particularly popular among strength athletes.