what is l-arginine used for
L-Arginine is an amino acid found in red meat and other protein sources. The body uses this amino acid to make a substance called nitric oxide (NO) that dilates blood vessels to improve blood circulation. This is believed to be how L-arginine can help increase blood flow to the penis, allowing a firmer erection. In one study, it seemed as though using a low dose of L-arginine (500 mg three times a day) was no better than taking a placebo (sugar pill). However, this dose was effective in men with low levels of NO.