Optimum Nutrition Serious Mass is a premium weight gainer supplement designed to help athletes and bodybuilders increase muscle mass and body weight. Each serving provides 1,250 calories and 50g of protein along with complex carbohydrates to support muscle growth and recovery. Key features: • 1,250 calories per serving • 50g protein blend for muscle building • 252g complex carbohydrates • Includes essential vitamins and minerals • Ideal for hard gainers looking to increase mass • Easy mixing formula Serious Mass by Optimum Nutrition is specifically formulated for individuals who struggle to gain weight and need extra calories in their diet. The balanced blend of proteins, carbohydrates, vitamins and minerals helps support muscle recovery and growth when combined with proper resistance training. Mix with water or milk based on your caloric needs.