Supplement is not necessary for workout in Gym. However, few people want to build muscles much quicker than the others, for those protein supplements are essential as normally it takes time to build muscles. But with a proper protein supplement your muscle tissues get faster recovery and it helped to grow them as compared in a natural manner. You can try various protein supplements such as Whey Protein, Glutamine Protein, Creatine. Consult an expert before taking the supplements for better results according to your body type.