I've actually had very good experiences with Nitrix. However some of my best gains came when I stacked it with Cell-mass and No-Xplode. It seemed like every time I went to the gym my lifts were going up. I kinda actually stumbled on the stack because my roommate left half a tub of cell-mass and No-xplode behind when he moved out, so I figured what the heck I'll stack it all (because at the time I was only taking Nitrix). Not to sound like a BSN rep or anything, but I have no doubt if you try it you will be pleased. Nitrix works well by itself, but if you stack it with cell-mass and no-xplode I think you'll like the results. Its a little pricey (about $100 for 3 weeks or so), but I've definitely made some good gains on it, and I'm a somewhat experienced lifter (about 7 years, 3 years pretty serious).