I've had great results bulking up with True Mass. I looked at the protein matrix of a few other bulking powders and True Mass was by far the best one I saw. It's a little more expensive, and you can go through a tub of it pretty quickly if you're serious about bulking. HOWEVER, if you really want to bulk up, you need to be prepared to spend a few extra dollars on food/supplements, especially if you want your lean mass gains to last. True Mass is the real deal, and I'm ordering another tub of it today.