ON’s Serious Mass is the ULTIMATE weight gain formula. If you find it difficult to gain weight, Serious Mass will help you develop the physique you've always wanted!

What Does It Do?

Each delicious shake delivers an incredible 1,250 calories, but no added sugar. This includes 50 g of blended protein to support muscle growth and 250 g of carbohydrates. Supports growth of lean muscle mass

When Is The Best Time To Enjoy My Shake?

Simply mix up 2 scoops with milk or water in your ON shaker and enjoy between meals, post-workout and/or before bed.

No surprise that customers voted Serious Mass ‘Weight Gainer of the Year’ at the recent Bodybuilding.com Awards!

Suitable for vegetarians.