Serious Mass 5.45 Kg by Optimum Nutrition is a benchmark supplement for weight gain and muscle mass. Specifically designed for those with fast metabolisms or extreme energy needs, it delivers over 1250 calories per serving. Its formula includes complex carbohydrates and a blend of whey protein, calcium caseinate, and egg albumin, ensuring a sustained release of amino acids for muscle growth and recovery. Enriched with creatine, glutamine, and a variety of vitamins and minerals, Serious Mass provides total support for maximizing strength and metabolic well-being. Perfect for bodybuilders and hardgainers, this product guarantees massive caloric intake to boost muscle mass and enhance performance. Available in a 5.45 Kg value pack, it is recommended to consume between meals or before bedtime to maintain a constant anabolic state.