When you mention L-arginine these days, NO products inevitably come to mind; but before its use as a nitric oxide precursor, arginine was thought of as the ultimate growth hormone secretagogue. Whether you buy into NO products or have previously bought into GH secretagogues, there is one role that arginine plays that should make anyone seriously consider using it on a regular basis. Arginine has powerful nutrient partitioning effects.
Now, before we go any further, I must qualify my claims by saying, that most of the research thus far has been done in obese populations. Nevertheless, from this research, we now know that consistent supplementation with L-arginine can increase insulin sensitivity, improve endothelial function (better pumps and lower blood pressure), reduce fat mass, reduce inflammation, and spare skeletal muscle while dieting.
Recent studies indicate that L-arginine supplementation stimulates mitochondrial biogenesis and brown adipose tissue development possibly through the enhanced synthesis of cell signaling molecules (nitric oxide, carbon monoxide, polyamines, cGMP, and cAMP) as well as the increased expression of genes that promote whole body oxidation of excess carbs and fat. In addition, there is evidence that arginine reduces the ability of your body to convert carbs into fat.
So how much does one need to take? The studies done on humans have stayed around 8-9g per day. L-arginine is stable in water, so it can be incorporated into a protein drink even if you aren’t going to drink it right away. There doesn’t seem to be any concern that the dosage interferes with absorption of other neutral amino acids, either. (Flex Magazine, June 2013)