Hi there!
If it’s for stimulating the production of HGH, you should take between 3-12 grams of L-Arginine, or 3 grams if you take L-ornithine with it. L-Arginine, to be absorbed by the body needs to be taken 1 hour before eating, or 3 hours after eating. To stimulate HGH production, it’s best to take first thing on the morning, or right before bed.
If you’re taking it just to increase circulation and sperm count, then you need to follow the same schedule, but only take 3 grams of the stuff, once a day.
Also, you could try to find another thread dealing with this in this section, where someone posted 3 links with very good material about the effects of L-Arginine.
Hope this helps!