It's important to understand the body's physiology. Your weightlifting tears down muscle tissue and it rebuilds between workouts. To rebuild it needs complete protein. However, the muscle cells are genetically programmed to use only a certain amount of protein. That's why bodybuilders use steroids: they enable the cells to absorb more protein.

As stated above (absent steroids), a good diet and regular intake of complete proteins at a certain level should assist your bodybuilding. If you want to augment the protein intake with supplemental protein, go ahead. But keep in mind that it's not necessarily productive. So much of it is passed out of the body.