Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer vs Serious Mass Chocolate Peanut Butter 2.73kg
Side-by-side comparison of scores, ingredients, prices and real customer feedback for Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer and Serious Mass Chocolate Peanut Butter 2.73kg.
Last verified: 07 Apr 2026 · Based on 18 reviews
Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer scores 72.0/100 vs Serious Mass Chocolate Peanut Butter 2.73kg at 70.0/100. Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer wins on certifications. Serious Mass Chocolate Peanut Butter 2.73kg is stronger on ingredient quality and value for money.
Which is better: Optimum Nutrition Serious M... or Serious Mass Chocolate Pean...?
Serious Mass Chocolate Peanut Butter edges ahead on value (80 vs 72) and costs £12.95 less, making it the stronger pick for budget-conscious gainers. The added creatine and higher calorie density per pound spent give it an edge for those in a dedicated bulking phase. Choose the original Serious Mass if you prioritise flavour variety or have used it loyally for years without issue.
— AIScored Editorial Team
How Do the Scores Compare?
Optimum Nutrition Serious M...
Optimum Nutrition
|
Serious Mass Chocolate Pean...
Optimum Nutrition
|
|
|---|---|---|
| Overall Score | 72.0 | 70.0 |
| Effectiveness |
80.0/100
Best
|
80.0/100
Best
|
| Ingredient Quality | 68.0/100 |
70.0/100
Best
|
| Value for Money | 72.0/100 |
80.0/100
Best
|
| Side Effects | 58.0/100 |
70.0/100
Best
|
| Certifications |
70.0/100
Best
|
50.0/100 |
| Best Price | £52.95 Amazon UK → |
£40.00
Holland & Barrett →
Cheapest
|
| Form | N/A | powder |
| Dose | N/A | None |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 14 | 4 |
Optimum Nutrition Serious Mass P...
Pros
- ✓Highly effective for calorie surplus and weight gain, with multiple reviewers reporting measurable mass gains (e.g. 2 stone in 3 months with training)
- ✓Strong long-term loyalty — several reviewers report 5–10+ years of consistent use
- ✓Good flavour profile (strawberry and banana rated as milkshake-like)
- ✓Excellent calorie density (1,250 kcal/serving) makes it practical for those who struggle to eat enough food
Cons
- ✗Inconsistent quality between batches — at least one reviewer reported a virtually flavourless delivery
- ✗Mixing challenges: oversized scoop won't fit most shaker bottles, and blender is often needed to avoid clumping
- ✗Digestive discomfort (bloating, gas, heaviness) reported by multiple users — typical of high-maltodextrin mass gainers
- ✗Premium price point relative to own-brand alternatives, though most reviewers consider it justified
Best For
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
What does the data say about Optimum Nutrition Seri... vs Serious Mass Chocolate...?
Both products are Optimum Nutrition's Serious Mass formula, so the core concept is identical — a high-calorie powder aimed at hard gainers. The key differences are price, size, and nutritional specifics. The Chocolate Peanut Butter variant at £40.00 scores 70/100 overall but offers better value (80/100 vs 72/100) and brings some meaningful extras: 1,263 kcal per serving, 50g protein from a whey/casein blend, and 3g of creatine monohydrate baked in. The original at £52.95 scores 72/100 overall with slightly lower ingredient quality (68/100 vs 70/100) but has a longer track record — some users have stuck with it for a decade, reporting measurable gains like 2 stone in three months.
If budget matters and you want creatine without buying it separately, the Chocolate Peanut Butter at £40 makes more sense. The original suits those who prefer familiar flavours like strawberry or banana and want something with proven long-term use behind it.
Practically, both require a blender — the scoops are too large for standard shakers. The Chocolate Peanut Butter carries 26g of sugar and 1.56g sodium per serving, worth noting if you're monitoring either.
Optimum Nutrition Serious Mass is one of the market's most established mass gainers, delivering approximately 1,250 calories and 50g protein per two-scoop serving alongside creatine, glutamine, and a full vitamin/mineral blend.
What are the key differences?
Frequently Asked Questions
Which is better, Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer or Serious Mass Chocolate Peanut Butter 2.73kg? ▼
Is Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer worth the price compared to Serious Mass Chocolate Peanut Butter 2.73kg? ▼
Which has fewer side effects? ▼
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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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