Just these 3 basics when used properly can add slabs of real, lean, sustainable muscle mass. They should be part of any serious bodybuilder's arsenal for building mass.
I remember years ago when I first started lifting, I got results like you would not beleive just from using BCAA's alone!
Throw in a couple quality whey protein concentrate shakes a few times a day and you can really pack on the muscle!
I agree with everyone's advice here. There are a variety of supplements that you can take but make sure that your main focus is still on the work that you have to do. There is only so much that taking supplements will do for you, but the results that you want will only come from hard work.
While there are no pills that can actually convert adipose (fat) tissue into muscle tissue, there is one excellent supplement that does give great "body recomposition" effects, which is burning off fat while adding lean muscle, and I believe that is ultimately what you are looking for. The name of that supplement is Ostarine MK-2866, and it is in a class of compounds called SARMS, short for Selective Androgen Receptor Modulators. These "SARMS" ... especially Ostarine, target androgen receptors on the body that are responsible for triggering muscle growth, while the compound also has a great affinity towards burning off fat stores from the body as well...so you are left weith more lean muscle and less fat. This sounds like it is what you are looking for.
Naturalbodybuilder.com - Natural Bodybuilding and Fitness Information.