The formula of Serious Mass by ON is mainly aimed at building muscle mass. The product is ideal for people who find it difficult to gain weight and supports the increase in girth and further development of the physique.To gain mass and weight, you need to provide the body with enough calories. Sometimes it is difficult to properly meet the increased nutritional needs in order to build muscle tissue and put more weight on the scale. For such cases Serious Mass was developed. For people with fast metabolisms, who are also very active during the day, it is in fact practically impossible to get the right nutrients in sufficient quantities every day through the conventional diet.Thanks to the calorie-rich formula with high protein and carbohydrate content and an extensive range of added vitamins, minerals and certain nutrients essential for muscle growth, Serious Mass meets this need. Each serving contains 1250 high quality calories and provides more than 50g of protein and 250g of carbohydrates. Serious Mass can be consumed as a snack, after a workout or simply instead of a meal and is an ideal companion for those who show some ambition in the weight room.