This synthetic version of an energy source produced naturally in the body is stored in the muscles for use during exercise. And it works! Multiple studies show that creatine does help speed recovery and the growth of lean-muscle mass after a workout. Manufacturers used to agree that new creatine users should start with a weeklong "loading phase" of 20 grams per day; however, recent research shows that this isn't necessary, according to Chris Mohr, Ph.D., R.D., adjunct professor of nutrition at the University of Louisville. You can start taking creatine at the normal dose of three to five grams per day after a workout. You can even mix it directly with your protein powder.