Extreme Calorie Power for Rapid Weight Gain

Optimum Nutrition Serious Mass is built for those who struggle to gain size and need serious calories to grow. Each massive serving delivers over 1200 calories, making it the ultimate weight gainer for hard gainers and high-metabolism athletes. Packed with 250 g+ of carbohydrates and 50 g of protein, it fuels your body with the energy and nutrients needed to drive weight gain, muscle fullness, and long-lasting training performance.

Muscle-Building Nutrition with Creatine & Glutamine

Serious Mass goes beyond basic mass gainers by adding creatine and glutamine to support strength, recovery, and muscle repair. The high-quality protein blend helps build lean muscle tissue, while creatine boosts workout power and glutamine accelerates post-training recovery. With 23+ essential vitamins and minerals, this formula also supports overall health, metabolism, and daily performance.

Perfect for Hard Gainers and High-Energy Athletes

If your goal is to pack on size fast, Serious Mass makes it easy. Use it post-workout to refill glycogen and kick-start recovery, or between meals to dramatically increase daily calorie intake. Blend it with milk, fruits, nuts, or peanut butter for even more calories and a richer taste. With just 8 ultra-dense servings per 2.72 kg tub, every scoop delivers serious results for serious growth.