Optimum Nutrition Serious Mass is a powerful High Protein Muscle Building & Weight Gain Formula. It is designed to help individuals looking to increase body mass. This supplement is an Artificially Flavored Strawberry Protein Powder Supplement. Per serving, Serious Mass provides a substantial nutritional profile, including 50g of Protein to help build and maintain muscle, 1,250 Calories to help boost calorie intake, and 252g of Carbohydrates. The product size is a large container with a Net Wt. 6 LB (2.72 KG), providing 8 servings. It is a high-calorie supplement that is typically taken in addition to normal calorie intake.