OPTIMUM NUTRITION Serious Mass powder supports muscle building, weight gain, and helps fuel workouts with up to 1260 calories, 50g of protein, up to 253g of carbohydrates, and 5g of creatine monohydrate in every serving ^1,7– all in a convenient shake for easy consumption.

Serious Mass is our highest-calorie weight gain formula – created specifically to provide maximum macros for athletes with extraordinary muscle and performance goals¹. Along with carbs for fueling your most intense workouts and calories to help support your bulking diet, the entire 50g of complete protein comes from fast-digesting whey protein concentrate from milk^1,3. It’s also a good source of 19 vitamins and minerals and delivers 8g of naturally occurring glutamine per serving.

Choose from five rich, great-tasting flavors for a seriously delicious routine you’ll always look forward to in your performance-driven lifestyle. Trusted by elite strength athletes all over the world, it’s everything you’ve come to expect from OPTIMUM NUTRITION: The World’s #1 Sports Nutrition Brand.