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Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) vs Serious Mass Cookies & Cream 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 Cookies & Cream 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 Cookies & Cream 2.73kg at 70.0/100. Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) wins on certifications. Serious Mass Cookies & Cream 2.73kg is stronger on effectiveness and value for money.

Which is better: Critical Mass Professional ... or Serious Mass Cookies & Cream 2.73kg?

Applied Nutrition Critical Mass edges ahead with a higher overall score (71 vs 70) and superior ingredient profile, including ISO-XP whey isolate, creatine, and HMB. Choose Optimum Nutrition Serious Mass if you prioritise taste, mixability, and a lower price — it delivers 1,250 kcal per serving at £40 versus £62.76.

— AIScored Editorial Team

How Do the Scores Compare?

Critical Mass Professional ...
Serious Mass Cookies & Cream 2.73kg
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings)
Critical Mass Professional ...
Applied Nutrition
Serious Mass Cookies & Cream 2.73kg
Serious Mass Cookies & Cream 2.73kg
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
30.0/100
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 Cookies & Cream 2.73kg

Pros

  • Excellent taste and mixability (mentioned in 3 of 4 reviews)
  • High calorie density (1,250 kcal per serving) supports rapid weight gain for hardgainers
  • 50g protein per serving aids muscle protein synthesis and recovery
  • Added 3g creatine monohydrate per serving (evidence-based for strength and muscle gains)

Cons

  • Extremely high sugar content (12g per serving) and 250g carbs may cause energy crashes or GI distress in sensitive individuals
  • Not third-party tested or certified (no NSF, Informed-Sport, or banned substance screening listed)
  • Contains common allergens (milk, soy, wheat, gluten) limiting accessibility
  • Very high serving size (336g per scoop) makes convenient dosing impractical; typically mixed with large volumes of liquid

Best For

Hardgainers and ectomorphs struggling to consume adequate calories Strength athletes and bodybuilders in caloric surplus phases Individuals with high-performance metabolisms requiring 3,000+ daily calories Post-workout recovery during bulking phases
View full review →

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

Both products are calorie-dense mass gainers in powder form, but they differ meaningfully in formulation. Applied Nutrition's Critical Mass (£62.76, 71/100) delivers around 1,000 calories per 150g serving with 42g of ISO-XP whey protein isolate — a higher-quality protein source than the blend typically found in Optimum Nutrition's Serious Mass (£40.00, 70/100), which offers 1,250 calories and 50g protein per 250g serving. Critical Mass also includes creatine monohydrate, HMB, leucine, and glutamine, giving it a more targeted performance profile. Serious Mass keeps things simpler but packs in more raw calories, with 250g of carbohydrates per serving — though that comes with 12g of sugar and a real risk of GI discomfort for sensitive stomachs.

If you're a hardgainer who wants functional extras alongside your calories, Critical Mass is the better pick despite the higher price. If you just need maximum calories quickly and aren't fussed about performance additions, Serious Mass delivers more per serving at a lower cost. Critical Mass users should use a blender — the large serving size clumps badly in a shaker alone.

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 Coo..
80.0/100
Ingredient Quality
Critical Mass Pr..
70.0/100
Serious Mass Coo..
70.0/100
Value for Money
Critical Mass Pr..
76.0/100
Serious Mass Coo..
80.0/100
Side Effects
Critical Mass Pr..
62.0/100
Serious Mass Coo..
70.0/100
Certifications
Critical Mass Pr..
72.0/100
Serious Mass Coo..
30.0/100

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 Cookies & .. is best for: Hardgainers and ectomorphs struggling to consume adequate calories, Strength athletes and bodybuilders in caloric surplus phases

Frequently Asked Questions

Which is better, Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) or Serious Mass Cookies & Cream 2.73kg?
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 71.0/100 overall while Serious Mass Cookies & Cream 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 Cookies & Cream 2.73kg is better for Hardgainers and ectomorphs struggling to consume adequate calories and Strength athletes and bodybuilders in caloric surplus phases.
Is Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) worth the price compared to Serious Mass Cookies & Cream 2.73kg?
Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) costs £62.76 while Serious Mass Cookies & Cream 2.73kg is £40.00. For value, Critical Mass Professional Lean Mass Gainer Vanilla 6kg (40 Servings) scores 76.0/100 vs Serious Mass Cookies & Cream 2.73kg's 80.0/100. Serious Mass Cookies & Cream 2.73kg delivers better value relative to its quality. Note that Critical Mass Profes comes as powder while Serious Mass Cookies 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 Cookies & Cream 2.73kg scores 70.0/100. Reviewers report fewer side effects with Serious Mass Cookies & Cream 2.73kg. For certification and testing, Critical Mass Profes scores 72.0/100 vs Serious Mass Cookies's 30.0/100. 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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