Optimum Nutrition Serious Mass (2.73kg)

A high-calorie weight gainer built for anyone who struggles to eat enough to build size — 1250 calories and 50g protein per serving to support serious mass gains.

Why choose Serious Mass

• 1250 calories per serving — genuinely built for weight gain, not a light snack
• 50g protein per serving — supports muscle growth alongside the calorie surplus
• 2.73kg tub — 8 servings to build size

Nutritional information (per 334g serving)

Calories: 1250 | Protein: 50g | Carbohydrates: 252g (of which sugars: 20g) | Fat: 4.5g (of which saturates: 1.5g).

How to use

Mix 2 scoops with 600-750ml of cold water or milk. Use between meals to add calories without needing to eat more solid food.

Frequently asked questions

Who is Serious Mass actually for?
Anyone who struggles to eat enough calories to gain weight or size through food alone — often called "hardgainers." It's not intended for people already eating a calorie surplus.

Do I need to drink a full serving at once?
Not necessarily — some people split it into smaller portions throughout the day if 1250 calories in one sitting feels like too much.

Can I use this alongside regular meals?
Yes — it's designed as an addition between meals to boost total daily calories, not a meal replacement.