Product details

When it comes to packing on serious size, consistency in your calorie intake is everything. But for “hardgainers” or athletes with hyper-fast metabolisms, eating enough whole food to grow can feel like a full-time job. Optimum Nutrition Serious Mass Gainer in Classic Chocolate is the ultimate weight-gain formula designed to help you break through your mass-building plateaus.

This legendary, high-calorie powerhouse provides your body with the exact tools it needs to pack on lean mass, fuel intense recovery, and build the physical stature you’ve been chasing. Rich, smooth, and incredibly filling, the milk chocolate flavour transforms a massive macro hit into a delicious, decadent shake.

Key Benefits

Massive Caloric Density: Delivers a whopping 1,250 clean calories per serving when mixed with water (and even more when blended with dairy milk). It provides the essential caloric surplus your body needs to build size.
High-Performance Protein Matrix: Packed with 50 grams of high-quality protein derived from a premium blend of fast- and slow-digesting sources (including whey concentrate, calcium caseinate, and egg albumen) for a sustained release of muscle-building aminos.
Fuel for Explosive Strength: Fortified with 1 gram of creatine monohydrate per serving to boost ATP production, enhance your short-burst power output, and support muscle volume during heavy lifting.
Over 250g of Complex Carbs: Features an extensive carbohydrate profile with no added sugar to rapidly replenish muscle glycogen stores after exhausting workouts and support sustained energy production.
Essential Micronutrient Support: Enhanced with a comprehensive blend of 25 essential vitamins and minerals, focusing heavily on B vitamins and antioxidants, to support energy metabolism and overall physical wellness during rigorous training phases.

Nutritional Blueprint (Per 2-Scoop Serving)

Nutrients	Amount per Serving	Primary Purpose
Total Calories	1,250 kcal	Drives the caloric surplus required for heavy mass gain.
Premium Protein	50 g	Supports muscle protein synthesis and structural tissue repair.
Carbohydrates	252–254 g	Refuels depleted muscle glycogen and sustains recovery energy.
Creatine Monohydrate	1 g	Increases muscular strength, endurance, and cell hydration.
Glutamine & Glutamic Acid	Naturally Occurring	Minimises muscle breakdown and improves recovery times.

How to Use

Suggested Use for Serious Gainers: Mix 2 heaping scoops of Serious Mass Chocolate with 710 ml (24 oz) of cold water or low-fat milk in a blender. Blend for 45–60 seconds.

💡 Pro-Tip for Beginners: Because of the heavy caloric load, it is highly recommended that new users start with 1/2 scoop daily for the first week, gradually increasing to 1 or more full servings per day as your body adjusts.

When to take:

Post-Workout: Drink 30–45 minutes after exercise to fast-track muscle glycogen replenishment and recovery.

Between Meals: Sip 1/2 to 1 serving between meals to maintain a positive nitrogen balance throughout the day.

Before Bed: Drink 1/2 to 1 serving before sleep to provide your muscles with slow-release recovery nutrients overnight.

Stop struggling to eat your calories. Drink them with the world’s most trusted weight gain formula. Grab Optimum Nutrition Serious Mass Chocolate and turn your hard work into serious size!