Optimum Nutrition Serious Mass is a high-calorie weight gainer protein powder designed to help you build muscle and gain weight. Each serving provides 1,250 calories, 50 grams of blended protein, and over 250 grams of carbohydrates with no added sugar. It also includes essential vitamins and minerals, creatine, glutamine, and glutamic acid to support muscle recovery and immune health. This vanilla-flavored powder is ideal for post-workout recovery or as a meal supplement to help you achieve your fitness goals.