Take your physique and training to the next level with Optimum Nutrition’s Serious Mass. Packed with 50 grams of muscle-building protein per serving, Optimum Nutrition Serious Mass Protein Powder helps you gain weight and get the mass you work hard for every time you rip through an intense workout. For added nutrients with every serving, Serious Mass contains 25 vitamins and essential minerals, more than 250g of carbohydrates and no added sugar.