An article already exists on T-Nation that explains why arginine isn't worth it.
I was initially skeptical of arginine supplements to begin with. But I figured I would at least give them a try.
To test the pump enhancing effects this supposedly has, I decided to measure the pump in my arms after a workout with arginine, and one without.
I first measured how big a circumference increase I get from my arms without it and I ended up with a 1/2 inch increase. When I tried the same think a week later but this time with 2.5 grams of arginine AKG (this was more then the recommended dosage) the pump was the same 1/2 in increase, nothing changed.
I would recommend avoiding arginine supplements, simply because not only is your money best spent elsewhere, but really anything that claims to increase bloodflow might not really have all that big of an effective on gains.
The theory is that increased bloodflow results in more nutrients, oxygen, and hormones to be delivered in a shorter amount of time...........well, so what? They're going to get there anyway, so why bother? The benefits probably just aren't worth it anyway, and keep in mind, arginine in all it's various forms doesn't have a big effect on blood flow.
One last thing: