I recently read that using the amino acid arginine can cause a significant increase in IGF-1 levels. I've read a lot about IGF-1, and it sounds like this is an important hormone for muscle growth. Do you know how much arginine I should take?
What you read about arginine increasing IGF-1 levels originated with a study presented in the Journal of Parenteral and Enteral Nutrition. In that study, 45 subjects who used 30 grams of arginine aspartate a day for 14 days experienced a significant increase in blood IGF-1 levels.P> Unfortunately, I don't think this study really has all that much application for bodybuilders--you see, the subjects in this recent arginine study were between the ages of 67 and 82. Typically, by that age, a number of our bodies' key hormones will be well below what they are when we're in our 20's and 30's. It's extremely possible that arginine does not increase IGF-1 levels in young, healthy bodybuilders. But, hopefully, someone will study the effects 30 grams of arginine aspartate has on bodybuilders, and hopefully, they'll measure not only IGF-1 levels but body composition and strength as well--these are the most important factors to me and most other supplement users. For now, I'd say hold off on arginine--there are better supplements to spend your hard-earned money on.