Just as they did with their SX-7 Series, turning Hydroxycut SX-7 into a full blown series now consisting of more than 10 items. Muscletech are also getting ready to extend their slickly themed Hydroxycut SX-7 Black Onyx into a line of its own. At the moment the brand do just have the one black and gold themed product, but are going to be turning it into a three supplement series over the next few months. The first item to be added will be PhosphaGrow, which like Muscletech’s upcoming Performance Series supplement Phosphamuscle, will be based around the increasingly popular phosphatidic acid. The second product is titled Test3X, a supplement you could have guessed just by its name is going to be a testosterone booster that unlike PhosphaGrow and more like Hydroxycut Black Onyx, will be packing a whole bunch of ingredients. As hardcore as Muscletech originally made Hydroxycut Black Onyx out to be, it seems they are now looking to continue that theme into the muscle building category an area the red SX-7 Series has yet to really venture.