Optimum Nutrition Serious Mass (2lbs, Chocolate Flavor) is a powerful weight gainer formulated for individuals who want to build muscle size, gain healthy weight, and enhance workout performance. Each serving delivers a rich blend of high-quality protein, complex carbohydrates, vitamins, and minerals to fuel your body for intense training and fast recovery. Perfect for hardgainers, athletes, and fitness enthusiasts, this calorie-dense formula helps increase muscle mass while supporting strength development. The smooth chocolate flavor mixes easily and tastes delicious, making it simple to add extra calories to your daily routine. Whether used post-workout or between meals, Serious Mass is your go-to supplement for next-level gains.