Your cart is empty!
Select a category below that fits with your goal
Select a category below that fits with your goal
Optimum Nutrition Serious Mass Gainer Protein Powder is a high-calorie mass gainer. Gaining enough calories and nutrients can be challenging when relying on whole foods alone - not to mention the stress this can put on the digestive system. Formulated for those who struggle to pack on size, Serious Mass delivers a massive protein hit to bulk up even the fastest metabolism.
Serious Mass is one of our favourite mass gainer products. Delicious, convenient, and easy on the digestive system, Serious Mass is the secret to sustainable weight gain. Because it contains a huge range of added vitamins and minerals, Serious Mass also functions as a general health supplement to support the way you look, feel, and perform.