Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
L-arginine is an amino acid and something we naturally have within our bodies. Under normal circumstances, it plays a role in nitric oxide production, which in turn plays a crucial role in allowing blood to rush into the penis to cause an erection.

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The role of the endothelium in erectile function became clearer with the observation that the phosphodiesterase type 5 (PDE5) inhibitor, sildenafil, enhanced erectile function. Erection occurs with the release of nitric oxide (NO) from the vascular endothelial cells.17 The reduction in endothelial cell production of NO results in the negative impact on the smooth muscles in the corporal bodies and results in less relaxation of the smooth muscle cells with decrease in blood supply and resulting ED. A similar phenomenon is well known to impact the coronary arterial system resulting in CVD.