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Serious Mass Chocolate 2.73kg

by Optimum Nutrition

11 reviews analysed · 2 sources · Last verified: 01 Mar 2026 · Price data: 18 Feb 2026 · Confidence: 37% · Reviewed by Bart, Health & Tech Enthusiast
Serious Mass Chocolate 2.73kg
68
Overall Score
Above Average

Compare Prices

Holland & Barrett
£40.00 View →
Amazon UK
£52.95 View →
Verdict: Above Average View Mass Gainers Rankings →

Optimum Nutrition Serious Mass is a long-established, high-calorie mass gainer delivering 1,250 calories and 50g protein per 334g serving, primarily via maltodextrin, whey concentrate, casein, and egg albumen, with added creatine monohydrate and a broad vitamin-mineral complex. Best for Hard gainers and ectomorphs struggling to meet caloric targets through food alone and People with low appetite or medical conditions limiting solid food intake.

According to the AIScored 0–100 scoring system, Serious Mass Chocolate 2.73kg by Optimum Nutrition scores 68.0/100, ranking #14 out of 23 products in Mass Gainers (2026). Strongest category: Effectiveness (78.0/100). Weakest: Certifications (35.0/100).

Data quality note: this page currently has limited evidence coverage (low review/source volume or lower confidence). Treat this as directional and cross-check with primary sources.

Is Serious Mass Chocolate 2.73kg worth buying?

“If you're a hard gainer who needs calories, Serious Mass gives you 1,250 per serving with 50g of protein and creatine monohydrate—helpful if you can't stomach enough whole food. At 68/100, it's reliable and straightforward, but you're basically drinking liquid carbs so factor that into your daily macros.”

— AIScored Editorial Team, Mar 2026

What Do Reviewers Say About Serious Mass Chocolate 2.73kg?

Sample excerpts from currently available source material used in this product analysis.

"Have this product on subscribe and save so only recently opened my most recent delivery, and there is next to no flavour, never had this issue before, but with this bag it taste horrible"

"I only use this brand of mass gainer… reason being it sits will in my digestive system, it definitely does what it supposed to do. I have used other brands, cheaper brands but they do not pack the punch this do 💪 I have literally been buyin..."

"It's helping me put on weight. I added a tablespoon of peanut butter and a banana, tastes really good with the strawberry one. This seems to be the best mass gainer, I've looked around and this is always said to be the best with approved in..."

"I don’t use this protein for the gym I use it cos I struggle to eat normal food and so this sometimes becomes my only source of food and with 1250 calories per shake I know if I drink 2 a day I’ll get all the nutrients I need infact probabl..."

"This protein powder is an excellent for anyone serious about gaining mass. The large size offers fantastic value, and the mix is effective and potent. It mixes well, taste good and is essential for hitting those high-calorie and high-protei..."

How does Serious Mass Chocolate 2.73kg score?

Detailed score breakdown and key findings from our analysis of 11 reviews across 2 sources.

Effectiveness How well the product works based on user reviews
78.0/100
Good
Ingredient Quality Clean label, bioavailable forms, minimal fillers
63.0/100
Average
Value for Money Price relative to quality and quantity
64.0/100
Average
Side Effects Profile Higher = fewer/milder side effects reported
60.0/100
Average
Certifications & Testing Third-party testing, GMP, and quality certifications
35.0/100
Below Average
Overall Score Weighted overall recommendation
68.0/100
Average

Pros

  • +Extremely high calorie density (1,250 kcal/serving) — effective for hard gainers and those with poor appetite
  • +50g complete protein per serving from multiple sources (whey concentrate, casein, egg albumen)
  • +Includes 3g creatine monohydrate per serving — added performance and muscle benefit
  • +Comprehensive vitamin and mineral profile covering most micronutrient needs
  • +Strong brand reputation with consistent quality across decades; Optimum Nutrition is widely regarded as a gold standard

Cons

  • -Maltodextrin is the dominant carbohydrate source — fast-digesting, high glycaemic, with limited nutritional value beyond calories
  • -334g serving size is impractical for standard shaker bottles and requires a blender for best results
  • -Reported digestive discomfort and bloating in a subset of users, likely due to serving volume and maltodextrin load
  • -Not third-party tested; no Informed Sport certification noted on this SKU

Best For

Hard gainers and ectomorphs struggling to meet caloric targets through food alone People with low appetite or medical conditions limiting solid food intake Intermediate to advanced gym-goers training 4–6 days per week Athletes in caloric surplus phases seeking a calorie-dense post-workout shake

Watch Out

  • !Very high per-serving sugar (26g) and maltodextrin content — unsuitable for those managing blood sugar or insulin sensitivity
  • !Significant allergen load: contains milk, egg, gluten/wheat; may contain peanuts and soy
  • !Batch flavour inconsistency reported by at least one subscriber — flavour quality not always uniform
  • !Calorie surplus can lead to fat gain if training volume and intensity are insufficient to utilise the extra calories

What is Serious Mass Chocolate 2.73kg?

Serious Mass Chocolate 2.73kg is a mass gainers product by Optimum Nutrition in powder form, scoring 68.0/100 on AIScored.

  • SUPPORTS MUSCLE BUILDING & WEIGHT GAIN1,250 CALORIES* – HELPS BOOST CALORIE INTAKE50 g▲ SOURCE OF PROTEIN – HELPS BUILD AND MAINTAIN MUSCLE▪Serious weight gain requires serious calories.
  • However, those who need the extra calories most often have the toughest time consuming enough of them.
  • For many aspiring to be bigger, a highly active metabolism, weaker appetite and on-the-run lifestyle can make it a real challenge to consume enough calories through whole foods alone.
  • Serious Mass is the ultimate in weight gain formulas.With 1,250 calories per serving to boost daily calorie intake, 50g high protein to support muscle growth and repair, over 250g carbohydrates helping support muscle recovery , and now with 3g added Creatine to support performance per serving, you’ve got nothing to lose and lots to gain.
  • It is time to stop thinking small and get serious – SERIOUS MASS®.

What's Inside Serious Mass Chocolate 2.73kg?

Serious Mass Chocolate 2.73kg contains 43 active ingredients: Per, Fat, of which saturates, Carbohydrates and more.

Active Ingredients

Per
100g / Per 334g Serving : Energy 1582kJ / 5284kJ / 378kcal / 1263kcal
Fat
1.7g / 5.5g
of which saturates
0.7g / 2.4g
Carbohydrates
75g / 251g
of which sugars
7.7g / 26g
Protein
15g / 50g
Salt
0.47g / 1.56g
Vitamin D
1.2µg / 4.0µg
Vitamin E
2.7mg / 9.0mg
Vitamin K
22µg / 75µg
Vitamin C
19mg / 64mg
Thiamin
0.27mg / 0.89mg
Riboflavin
0.34mg / 1.1mg
Niacin
3.9mg / 13mg
Folic Acid
45.1µg / 151µg
Biotin
11µg / 37µg
Pantothenic Acid
1.4mg / 4.5mg
Calcium
180mg / 600mg
Phosphorus
159mg / 532mg
Magnesium
85.8mg / 287mg
Iron
5.4mg / 18mg
Zinc
3.2mg / 11mg
Copper
0.41mg / 1.4mg
Manganese
0.60mg / 2.0mg
Fluoride
1.0mg / 3.5mg
Selenium
17µg / 55µg
Chromium
14µg / 46µg
Molybdenum
17µg / 57µg
Creatine
0.9g / 3.0g Macro Nutrient table: Energy Kcal per 100g 378Kcal
Energy kJ per
100g 1582kJ
Fats per
100g 1.7g
Of which Saturates per
100g 0.7g
Carbohydrates per
100g 75g
Sugar per
100g 7.7g
Protein per
100g 15g
Salt per
100g 0.47g
Fats per serving
5.5g
Of which Saturates per serving
2.4g
Carbohydrates per serving
251g
Sugar per serving
26g
Protein per serving
50g
Salt per serving
1.56g
Serving size
334g

Other Ingredients

Maltodextrin, WHEY Protein Concentrate [MILK], Calcium CASEINATE [MILK], Fat-Reduced Cocoa Powder, Creatine Monohydrate, Flavouring, MILK Mineral Complex, Medium Chain Triglycerides [MILK], EGG Albumen, Sodium Chloride, Dipotassium Phosphate, Vitamin & Mineral Blend (Sodium L-Ascorbate, Ferric Pyrophosphate, D-Alpha-Tocopheryl Acetate, Nicotinamide, Zinc Oxide, Retinyl Acetate, Calcium D-Pantothenate, Sodium Fluoride, Manganese Sulphate, Potassium Iodate, Cyanocobalamin, D-Biotin,

Allergens: Contains: Eggs, Gluten, Lactose, Milk, Peanuts may contain, Soy may contain, Wheat

Is Serious Mass Chocolate 2.73kg Independently Tested?

?

No Third-Party Testing Visible

We could not find evidence of independent third-party testing for this product. This doesn't mean it's unsafe, but independent verification provides additional assurance.

How We Score Supplements

Our methodology analyses review data, ingredient science, and product information, then scores each product on a 0-100 scale across evidence-based categories:

1

Effectiveness

How well the product delivers its claimed benefits, based on reviews and ingredient evidence.

2

Ingredient Quality

Bioavailable forms, clinically effective dosages, clean label, minimal fillers.

3

Value for Money

Price relative to ingredient quality, dosage count, and effectiveness.

4

Side Effects Profile

Higher score = fewer side effects. 100 means virtually no adverse reactions reported.

5

Certifications & Testing

Third-party lab testing, GMP certification, and independent quality verification.

6

Overall Score

Weighted combination of all factors. Our bottom-line recommendation.

How Does Serious Mass Chocolate 2.73kg Compare?

See how this product stacks up against the top-rated mass gainers in our database.

Product Score Price
Serious Mass Chocolate 2.73kg (this) 68.0 £40.00
Critical Mass Professional Lean ... 80.0 £40.00

Price History (90 days)

Quick Facts

Form
powder
Serving
1 serving
Vegan
No

Frequently Asked Questions

Is Serious Mass Chocolate 2.73kg worth buying in 2026?
Serious Mass Chocolate 2.73kg scores 68.0/100 in our analysis, based on 11 reviews. Optimum Nutrition Serious Mass is a long-established, high-calorie mass gainer delivering 1,250 calories and 50g protein per 334g serving, primarily via maltodextrin, whey concentrate, casein, and egg albumen, with added creatine monohydrate and a br...
What is the best price for Serious Mass Chocolate 2.73kg in the UK?
The best price we found is £40.00 at Holland & Barrett. We compare prices from 2 UK retailers and update them regularly.
What are the pros and cons of Serious Mass Chocolate 2.73kg?
Pros: Extremely high calorie density (1,250 kcal/serving) — effective for hard gainers and those with poor appetite. 50g complete protein per serving from multiple sources (whey concentrate, casein, egg albumen). Includes 3g creatine monohydrate per serving — added performance and muscle benefit. Cons: Maltodextrin is the dominant carbohydrate source — fast-digesting, high glycaemic, with limited nutritional value beyond calories. 334g serving size is impractical for standard shaker bottles and requires a blender for best results. Reported digestive discomfort and bloating in a subset of users, likely due to serving volume and maltodextrin load.
Is Serious Mass Chocolate 2.73kg third-party tested?
We could not find evidence of third-party testing for this product. While this does not mean the product is unsafe, independent testing provides additional quality assurance.
How does Serious Mass Chocolate 2.73kg compare to Critical Mass Professional Lean Mass Gainer Banana 2.4kg (16 Servings)?
Serious Mass Chocolate 2.73kg scores 68.0/100 while Critical Mass Professional Lean Mass Gainer Banana 2.4kg (16 Servings) scores 80.0/100. Read full comparison →

Disclaimer: AIScored provides research-backed summaries based on publicly available reviews and product information. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Affiliate links may earn us a commission at no extra cost to you.

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