dude, you can't loose fat and gain lean mass at the same time unless you're obese and have a perfect diet, or unless you're on certain chemicals.
that being said, i thought
nitrix already had creatine in it.
also, i think nitrix is a waist of money.
all you need for supplements to gain some lean mass are a good low carb protein powder, creatine, mutli-vitamin. unless you're a hardgainer or have a screaming metabolism. then you can try weightgainers.
but nitric oxide, as much as i like it, really doesn't do anything to help you gain mass.