This is a tempting assumption, muscle is made up of protein right, so therefore loading up on protein will increase muscle mass. Unfortunately it doesn't work like that, the body prefers to store energy as glycogen or fat.
Protein turnover increases with exercise training, and during training, your muscles use some protein as fuel (10%). This means you will have a greater need for protein than a sedentary person, and consuming adequate protein is important to reduce catabolism (breakdown) of your protein stores. If the goal is to gain muscle, strength training is your best bet and should induce muscle gain with adequate dietary protein. It's important to make sure you are not fasting before or after exercise as your body will use up the glycogen stores and move onto protein to get the all important glycogen to fuel the muscles and brain.
The recommended percent energy from protein is 15% to 25% of your diet and a diet varying in protein sources will provide you with all the amino acids you need to maintain or increase muscle mass negating the need for supplement use.
Protein supplements are an expensive addition to the trolley and have not been shown to increase muscle mass over and above dietary protein. For most people, taking excessive protein in supplement form will not do the body much harm. The protein will be used as energy (excess stored as fat) and the nitrogen and sulphur will be broken down by the kidneys and excreted in urine. Problems may arise with people who have liver problems or impaired renal function.
In New Zealand we have high intakes of protein. The RDI (recommended daily intake) is 64g and 46g for adult men and women respectively. Our median intake is 105g for men and 71g for women. Children in New Zealand have been found to consume double the RDI's specific for their age.
In summary if you want to bulk up, don’t head to the supplement aisle but increase your overall energy intake, include a variety of protein rich foods in your diet and do strength training.