Optimum Nutrition Serious Mass

Optimum Nutrition Serious Mass – High-Calorie Mass Gainer for Serious Size

Build serious size, strength, and muscle mass with ON Serious Mass – the ultimate weight gainer for hard gainers and athletes looking to bulk up fast. Each serving delivers a massive dose of calories, protein, carbs, and essential nutrients to help you push past plateaus and see real gains.

Packed with 1,250 calories, 50g of high-quality protein, and over 250g of complex carbs, Serious Mass fuels intense workouts and recovery with the nutrition your body needs to grow—fast.

Key Benefits:

• 1,250 calories per serving (with water)

• 50g of blended protein (whey, casein, egg)

• 250+ grams of complex carbs – no added sugar

• 25+ essential vitamins and minerals

• Creatine, glutamine & MCTs included

• Great taste and easy mixing

Why Choose Serious Mass?

This isn’t your average gainer. Serious Mass is made for people who struggle to put on weight or need major calorie support to meet their goals. Whether you’re in a bulking phase, recovering from intense training, or trying to break through a plateau, this is your heavy-duty solution.