Steriods seems to work but from MTV's show, once you get off; it's gone again except for all the great side-effect: baldness, roid-rage, smaller libido.....
Beside that, it's nutrition, DIET, excercise, and REST. Make sure to eat in surplus and if you can gain 1 lbs a week, that is amazing. The ideal goal of all bodybuilder is to gain 1 lbs a week.