On Serious Mass

Build Size the Smart Way 💪

Gaining muscle comes down to one key factor — consistently eating more calories than you burn. But for a lot of people, getting enough food in every day can be a challenge.

That’s where Optimum Nutrition Serious Mass steps in.

Designed for those chasing real size, this high-calorie formula makes it easier to hit your daily intake without force-feeding meals. Each full serve packs a massive 1250 calories, including 50g of protein and over 250g of carbohydrates to support growth, energy, and recovery.

You’re also getting more than just calories — with added creatine monohydrate and glutamine to help support strength, performance, and recovery, plus a blend of 20 essential vitamins and minerals. Best of all, there’s no added sugar — just quality nutrients in a convenient shake.

Key Benefits:

• Supports muscle growth and overall weight gain

• High-calorie formula to help maintain a calorie surplus

• 50g protein blend to build and maintain lean muscle

• Over 250g carbs to fuel training and replenish glycogen

• Includes creatine to assist strength and power output

• Fortified with essential vitamins and minerals

• Great for post-workout recovery or boosting daily intake

Who should use it?
Perfect for hard gainers, athletes training at high intensity, or anyone struggling to consume enough calories through whole food alone.

How & when to take:
Use it after training to support recovery or between meals to increase your daily calorie intake. Mix two scoops with around 700ml of water or milk in a blender. New users can start with half a serve to assess tolerance.

Mass Mackay Tip:
If size is the goal, consistency with your calories is everything — this is one of the easiest ways to stay on track.