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Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) vs Serious Mass Chocolate Peanut Butter 2.73kg

Side-by-side comparison of scores, ingredients, prices and real customer feedback for Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) and Serious Mass Chocolate Peanut Butter 2.73kg.

Last verified: 07 Apr 2026 · Based on 15 reviews

71.0
Quick Answer

Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 71.0/100 vs Serious Mass Chocolate Peanut Butter 2.73kg at 70.0/100. Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) wins on certifications. Serious Mass Chocolate Peanut Butter 2.73kg is stronger on effectiveness and value for money.

Which is better: Critical Mass Professional ... or Serious Mass Chocolate Pean...?

Optimum Nutrition Serious Mass edges ahead on effectiveness (80 vs 73) and value (80 vs 76) at a lower price. Applied Nutrition Critical Mass suits those who prefer a leaner calorie profile with added HMB and leucine for muscle retention, or who need a larger 6kg supply upfront.

— AIScored Editorial Team

How Do the Scores Compare?

Critical Mass Professional ...
Serious Mass Chocolate Pean...
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings)
Critical Mass Professional ...
Applied Nutrition
Serious Mass Chocolate Peanut Butter 2.73kg
Serious Mass Chocolate Pean...
Optimum Nutrition
Overall Score 71.0 70.0
Effectiveness 73.0/100 80.0/100
Best
Ingredient Quality 70.0/100
Best
70.0/100
Best
Value for Money 76.0/100 80.0/100
Best
Side Effects 62.0/100 70.0/100
Best
Certifications 72.0/100
Best
50.0/100
Best Price £62.76 Amazon UK → £40.00 Holland & Barrett →
Cheapest
Form Powder powder
Dose None None
Third-Party Tested ✗ No ✗ No
Reviews Analysed 11 4

Critical Mass Professional Lean ...

Pros

  • Over 1,000 calories per serving — highly efficient caloric surplus for hard gainers
  • Premium protein source: ISO-XP 95% Whey Protein Isolate at 42g per serving
  • Evidence-based performance additions: creatine monohydrate, HMB, leucine, and glutamine
  • Reduced-sugar formulation compared to conventional mass gainers

Cons

  • Batch-to-batch flavour inconsistency reported — some users find later purchases taste synthetic or chemical
  • Large 150g serving size can clump without a blender; shaker alone may not suffice
  • Contains milk, soy, and wheat — unsuitable for those with common allergens
  • Very high caloric density requires careful tracking to avoid unwanted fat gain

Best For

Hard gainers struggling to achieve a consistent caloric surplus Athletes in structured bulking or off-season mass phases Post-surgery or illness recovery requiring rapid muscle and weight rebuilding Halal-observant consumers needing a certified mass gainer
View full review →

Serious Mass Chocolate Peanut Bu...

Pros

  • Extremely high calorie density (1,263 kcal/serving) designed specifically for muscle gain
  • Substantial protein content (50g per serving) with dual whey/casein blend for sustained release
  • Added creatine monohydrate (3g/serving) supports strength and performance
  • Complete micronutrient profile with 25 vitamins and minerals at therapeutic doses

Cons

  • Very high sugar content (26g per serving) unsuitable for those managing blood glucose
  • High sodium per serving (1.56g, 26% RDA) may concern sodium-sensitive individuals
  • Large serving size (334g powder + 710ml water) makes it inconvenient for on-the-go use
  • Contains multiple allergens: milk, soy, wheat, egg; not suitable for allergic individuals

Best For

Hard gainers struggling to consume sufficient calories Bodybuilders and strength athletes in muscle-building phases Post-workout recovery nutrition Individuals aged 18-45 with no blood glucose or sodium concerns
View full review →

What does the data say about Critical Mass Professi... vs Serious Mass Chocolate...?

Applied Nutrition's Critical Mass and Optimum Nutrition's Serious Mass are both high-calorie powders aimed at hard gainers, but they differ in a few meaningful ways. Critical Mass delivers around 1,000 kcal per 150g serving alongside 42g of ISO-XP whey protein isolate — a higher-purity form than the blended whey and casein used in Serious Mass. It also includes HMB and leucine, which have decent evidence behind them for muscle retention, particularly during recovery from illness or surgery. Serious Mass counters with a bigger calorie hit — 1,263 kcal per serving — and 50g protein, though that comes with 26g of sugar and 1.56g of sodium per serving, worth noting if you're managing either.

On scores, Critical Mass edges ahead overall at 71.0/100 versus Serious Mass at 70.0/100, though Serious Mass actually scores higher on effectiveness (80 vs 73) and value (80 vs 76). At £40 for 2.73kg versus £62.76 for 6kg, Critical Mass works out cheaper per serving over the long run, though the upfront cost is higher.

For most people just trying to eat in a consistent surplus, Serious Mass is the simpler, cheaper entry point. If you're recovering from illness or injury and want a cleaner protein source with added recovery ingredients, Critical Mass makes more practical sense. Both lack third-party testing, so neither has a certification advantage. The large serving sizes on both mean a blender is genuinely useful — shakers often struggle with powders this dense.

Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) Winner 71.0/100

Applied Nutrition Critical Mass Professional is a high-calorie lean mass gainer delivering over 1,000 calories and 42g of protein per 150g serving, built around ISO-XP 95% Whey Protein Isolate with added creatine, HMB, leucine, glutamine, CLA, and MCT powder.

Effectiveness
Critical Mass Pr..
73.0/100
Serious Mass Cho..
80.0/100
Ingredient Quality
Critical Mass Pr..
70.0/100
Serious Mass Cho..
70.0/100
Value for Money
Critical Mass Pr..
76.0/100
Serious Mass Cho..
80.0/100
Side Effects
Critical Mass Pr..
62.0/100
Serious Mass Cho..
70.0/100
Certifications
Critical Mass Pr..
72.0/100
Serious Mass Cho..
50.0/100

What are the key differences?

Critical Mass Professio.. is best for: Hard gainers struggling to achieve a consistent caloric surplus, Athletes in structured bulking or off-season mass phases
Serious Mass Chocolate .. is best for: Hard gainers struggling to consume sufficient calories, Bodybuilders and strength athletes in muscle-building phases

Frequently Asked Questions

Which is better, Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) or Serious Mass Chocolate Peanut Butter 2.73kg?
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 71.0/100 overall while Serious Mass Chocolate Peanut Butter 2.73kg scores 70.0/100. Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) comes out ahead, scoring higher on effectiveness (73.0 vs 80.0). Critical Mass Professional Lea is best suited for Hard gainers struggling to achieve a consistent caloric surplus and Athletes in structured bulking or off-season mass phases. Serious Mass Chocolate Peanut is better for Hard gainers struggling to consume sufficient calories and Bodybuilders and strength athletes in muscle-building phases.
Is Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) worth the price compared to Serious Mass Chocolate Peanut Butter 2.73kg?
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) costs £62.76 while Serious Mass Chocolate Peanut Butter 2.73kg is £40.00. For value, Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 76.0/100 vs Serious Mass Chocolate Peanut Butter 2.73kg's 80.0/100. Serious Mass Chocolate Peanut Butter 2.73kg delivers better value relative to its quality. Note that Critical Mass Profes comes as powder while Serious Mass Chocola is powder, which may affect your preference.
Which has fewer side effects?
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 62.0/100 for side effects (higher means fewer reported issues) while Serious Mass Chocolate Peanut Butter 2.73kg scores 70.0/100. Reviewers report fewer side effects with Serious Mass Chocolate Peanut Butter 2.73kg. For certification and testing, Critical Mass Profes scores 72.0/100 vs Serious Mass Chocola's 50.0/100. Always consult a healthcare professional before starting any supplement.

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Disclaimer: AIScored provides data-driven comparisons based on publicly available reviews. This is not medical advice. Affiliate links may earn us a commission at no extra cost to you.

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