IGF-2 is a natural Growth Hormone (and Testosterone) booster.
FREE TEST is a natural Testosterone booster with AI and cortisol controlling properties.
HGHup is a natural Growth Hormone (and Testosterone) booster, and even though in the same "product category" as IGF-2, is a complete DIFFERENT product altogether.
LIT UP is a preworkout product.
As far as muscle gains, personally, IGF-2 stacked with FREE TEST is a great stack - some use HGHup instead of IGF-2 and that works as well, but my personal favourite is IGF-2.
Be aware that whether or not you gain muscle mass is NOT going to depend on what supplements you use, but primarily on your NUTRITION AND TRAINING, so you had best make sure that those two important factors are set up optimally for YOU re gains before looking at what supplements to add to COMPLIMENT them!