If you want the honest answer first, here it is: protein powders can help build muscle, but they are not magic, and they are often overhyped. They work best when they help you reach adequate daily protein intake and when they are paired with resistance training. On their own, they do not create muscle just because they come in a shaker bottle. The NIH Office of Dietary Supplements notes that protein is central to muscle growth and repair, but supplements marketed for exercise only support performance or body composition meaningfully when the underlying training and nutrition are in place.