Mutant Mass vs Serious Mass: Which Mass Gainer Is Better for Skinny Guys?
If you’re a skinny guy trying to pack on serious size, you’ve likely come across Mutant Mass, Mutant Mass Extreme 2500, and Serious Mass by Optimum Nutrition.
All three are high-calorie weight gainers made for hard-gainers — but which one gives you the most size, strength, and real-world results?
Let’s break it down and find your best match. 👇
What They’re Made For
| Product | Best For |
|---|---|
| Mutant Mass | Regular hard-gainers looking for clean calories and steady muscle gain. |
| Mutant Mass Extreme 2500 | Skinny guys with fast metabolisms who need a calorie bomb to gain size fast. |
| Serious Mass | Beginners or anyone struggling to eat enough — ideal for all-around weight gain and recovery. |
Quick Breakdown: Mutant Mass vs Mutant Mass Extreme 2500 vs Serious Mass
These three mass gainers are among the most popular in the UK — but each serves a slightly different purpose depending on how aggressively you want to bulk.
Here’s how they compare in key areas 👇
Calories per Serving
Mutant Mass: 1,100+ calories per serving
Mutant Mass Extreme 2500: 1,270 calories (or 2,540 daily if taken twice)
Serious Mass: 1,250 calories per serving
Protein Content
Mutant Mass: 56g protein
Mutant Mass Extreme 2500: 46g protein
Serious Mass: 50g protein
Carbohydrates
Mutant Mass: 192g complex carbs for steady energy
Mutant Mass Extreme 2500: 255g carbs for serious mass gain
Serious Mass: 252g carbs — great for calorie surplus and recovery
Fat Content
Mutant Mass: 8g fat per serving
Mutant Mass Extreme 2500: 7.5g fat
Serious Mass: 4.5g fat — leanest of the three
Size / Packaging
Mutant Mass: 6.8kg tub
Mutant Mass Extreme 2500: 5.45kg tub
Serious Mass: 5.4kg tub
Creatine Included?
Mutant Mass: ❌ No
Mutant Mass Extreme 2500: ❌ No
Serious Mass: ✅ Yes – includes creatine for added strength and recovery
Multivitamin Blend
Mutant Mass: ❌ No
Mutant Mass Extreme 2500: ❌ No
Serious Mass: ✅ Yes – includes essential vitamins and minerals
When to Use
Mutant Mass: After workouts or as a meal replacement
Mutant Mass Extreme 2500: Post-workout and before bed for maximum results
Serious Mass: Post-workout or between meals to maintain calorie intake
✅ Summary:
Mutant Mass – Balanced calorie and protein ratio; ideal for moderate bulking.
Mutant Mass Extreme 2500 – Best for extreme hardgainers needing massive calorie intake.
Serious Mass – Great for recovery and leaner bulks, thanks to creatine and vitamins.
Bottom Line
If you’re aiming for maximum mass, go with Mutant Mass Extreme 2500.
For a cleaner, balanced calorie intake, Mutant Mass is your best bet.
And if you prefer added creatine and vitamins, Serious Mass is a solid all-in-one option.
Which One Builds More Muscle?
Let’s be real — they’ll all help you gain weight. But your choice depends on how hard it is for you to eat and grow.
Mutant Mass Extreme 2500
The heavyweight king for true hard-gainers.
✔️ For fast metabolisms
✔️ If you can’t eat enough real food
✔️ If you want to bulk aggressively
Serious Mass
Solid all-rounder.
✔️ Easier on the stomach than Extreme 2500
✔️ Includes creatine + vitamins
✔️ Good for first-timers and lean bulkers
Mutant Mass
Perfect for lean, controlled gains.
✔️ Highest protein per calorie
✔️ Fewer carbs than the others
✔️ Great for lifters who want quality muscle, not just bulk
Taste, Flavour & Mixability
All three come in a variety of flavours like Chocolate, Vanilla, Cookies N’ Cream, and Banana.
| Product | Taste & Mixability Notes |
|---|---|
| Mutant Mass | Rich taste, thick texture, mixes well with milk. Great for bulking shakes. |
| Extreme 2500 | Surprisingly easy to drink despite the size — no clumps, no bloating. |
| Serious Mass | Smooth and lighter than others. Slightly sweeter. Easy for beginners. |
✅ Pro Tip: Use whole milk for more calories and a better texture. You can also blend with oats, peanut butter, or banana for a next-level shake.
How to Use Each One
Mutant Mass
➡️ 1–2 scoops post-workout or as a meal replacement.
Mutant Mass Extreme 2500
➡️ One full shake post-workout + another before bed = over 2,500 calories daily.
Serious Mass
➡️ Take between meals and post-workout. Good morning shake if you’re skipping breakfast.
Our Verdict: Which One Should You Buy?
| Goal | Pick This One |
|---|---|
| You want a clean bulk with more protein | Mutant Mass |
| You’re eating a lot but still not gaining | Mutant Mass Extreme 2500 |
| You’re a beginner or want creatine + vitamins included | Serious Mass |
| You’re bulking HARD and want big size fast | Extreme 2500 |
| You prefer a lighter shake with easier digestion | Serious Mass |
Final Thoughts
Whether you go with Mutant Mass, Extreme 2500, or Serious Mass, all three are powerful mass gainers that work — as long as you train hard, sleep well, and hit your calories consistently.
👉 If you’re struggling to eat enough and want extreme results, go with Mutant Mass Extreme 2500.
👉 If you’re after balanced, steady muscle growth, Mutant Mass is a great long-term gainer.
👉 If you want something simple, smooth, and nutrient-rich, Serious Mass is a solid all-round pick.
🔗 Related Links:
✅ Best Mass Gainers for Skinny Guys UK – Complete Guide
✅ Mutant Mass Extreme 2500 Review – Full Breakdown
✅ Serious Mass vs Gold Standard Whey – Which Is Better?
