The active ingredient in those three supps you listed is simply arginine. If you are looking for that "pump effect" don't waste your money on any of those products, just get plain old arginine. I paid $10.87 for a 120 ct. bottle of 1000mg caps, as opposed to over $70 for NO2. I actually get better results off of 4g plain arginine than I did for NO2 (tried it for 2 months right when it came out). As for truly BUILDING bigger muscles, read what StoneCold said.