Serious Mass Vanilla 5.4kg
by Optimum Nutrition
Optimum Nutrition Serious Mass is a long-standing, high-calorie mass gainer delivering 1,250 calories and 50g protein per 335g serving, making it one of the most calorie-dense products in its category. Best for Hard gainers struggling to consume enough calories through whole food alone and Individuals with low appetite or difficulty eating normal meals.
According to the AIScored 0–100 scoring system, Serious Mass Vanilla 5.4kg by Optimum Nutrition scores 62.0/100, ranking #23 out of 23 products in Mass Gainers (2026). Strongest category: Effectiveness (75.0/100). Weakest: Certifications (35.0/100).
Is Serious Mass Vanilla 5.4kg worth buying?
“Serious Mass is built for serious calorie intake with 1,250 calories per 335g serving, which is genuinely among the highest you'll find for getting real weight gains. At a 62/100 score, it's a straightforward workhorse that gets the job done with solid protein content and added creatine, though it won't win awards for ingredient sophistication.”
What Do Reviewers Say About Serious Mass Vanilla 5.4kg?
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 Vanilla 5.4kg score?
Detailed score breakdown and key findings from our analysis of 14 reviews across 2 sources.
Pros
- +Delivers genuine caloric surplus — 1,250 kcal per serving is among the highest in the category, effective for hard gainers
- +50g protein per serving supports muscle protein synthesis alongside the calorie load
- +Includes 3g creatine monohydrate per serving, a well-evidenced performance ingredient
- +Broad vitamin and mineral panel adds nutritional completeness, useful for those relying on it as a partial meal replacement
- +Strong brand trust and long track record — multiple reviewers report 5–10+ years of repeat purchase
Cons
- -Maltodextrin is the primary carb source — high glycaemic index, minimal nutritional complexity, and a marker of a budget-oriented formula
- -Mixing is problematic without a blender; oversized scoop won't fit standard shaker bottles, causing clumping
- -Some users report digestive discomfort, bloating, and excess gas — common with large maltodextrin loads
- -Not third-party tested; one reviewer noted a flavour quality inconsistency between deliveries
Best For
Watch Out
- !Requires a blender — shaker mixing results in clumps and an unsatisfactory texture
- !Very high carbohydrate load (250g per serving) is unsuitable for anyone with blood sugar sensitivity or who is not in a heavy training phase
- !Sucralose and carrageenan present for those avoiding artificial sweeteners or stabilisers
- !Contains milk, soy, and may contain gluten, eggs, nuts, and peanuts — significant allergen risk
What is Serious Mass Vanilla 5.4kg?
Serious Mass Vanilla 5.4kg is a mass gainers product by Optimum Nutrition in powder form, scoring 62.0/100 on AIScored.
- • What Is It: A high‑calorie weight gainer that supports muscle building and weight gain, delivering 1,250 calories per serving to help boost daily calorie intake.
- • Each serving provides 50 g protein to help build and maintain muscle and includes 3 g added creatine to help support performance.
- • Key Benefits: Provides 1,250 calories per serving to help boost daily calorie intake for effective weight gain.
- • Delivers 50 g of protein per serving as a source to help build and maintain muscle mass.
- • Supplies over 250 g of carbohydrate per serving, helping to support muscle recovery.
- • Contains 3 g added creatine per serving to help support performance.
- • How To Use: To prepare a shake, add 335 g (~2 heaped scoops) to a blender filled with 710 ml of water and blend for 30–45 seconds until smooth; store the product in a cool, dry place.
- • Key Ingredients: Per serving: 1,250 calories to help boost calorie intake; 50 g protein to help build and maintain muscle; over 250 g carbohydrate to help support muscle recovery; plus 3 g added creatine to help support performance.
What's Inside Serious Mass Vanilla 5.4kg?
Serious Mass Vanilla 5.4kg contains 37 active ingredients: Per, Fat, of which saturates, Carbohydrates and more.
Active Ingredients
- Per
- 100g / 335g portion: Energy 1572kJ / 5267kJ / 376kcal / 1259kcal
- Fat
- 1.8g / 6.2g
- of which saturates
- 1.0g / 3.4g
- Carbohydrates
- 75g / 250g
- of which sugars
- 3.6g / 12g
- Protein
- 15g / 50g
- Salt
- 0.57g / 1.89g
- Vitamin E
- 2.7 mg / 9.0 mg
- Viamin C
- 19 mg / 63 mg
- Thiamin
- 0.27 mg / 0.90 mg
- Riboflavin
- 0.34mg / 1.1mg
- Niacin
- 4.0 mg / 13 mg
- Pantothenic Acid
- 1.3 mg / 4.5 mg
- Calcium
- 227 mg / 760 mg
- Phosphorus
- 158 mg / 530 mg
- Magnesium
- 0.60 mg / 2.0 mg
- Iron
- 4.2mg / 14mg
- Zinc
- 3.0mg / 10mg
- Copper
- 0.30mg / 1.0mg
- Manganese
- 0.60mg / 2.0mg
- Fluoride
- 0.87 mg / 2.9 mg
- Selenium
- 16µg / 55µg
- Creatine
- 0.9g / 3.0g Macro Nutrient table: Energy Kcal per 100g 376Kcal
- Energy kJ per
- 100g 1572kJ
- Fats per
- 100g 1.8g
- Of which Saturates per
- 100g 1g
- Carbohydrates per
- 100g 75g
- Sugar per
- 100g 3.6g
- Protein per
- 100g 15g
- Salt per
- 100g 0.57g
- Fats per serving
- 6.2g
- Of which Saturates per serving
- 3.4g
- Carbohydrates per serving
- 250g
- Sugar per serving
- 12g
- Protein per serving
- 50g
- Salt per serving
- 1.89g
- Serving size
- 335g
Other Ingredients
Corn, Maltodextrin, WHEY Protein Concentrate [MILK] (Emilsifier: Lecithin [SOY]), Flavourings Creatine Monohydrate, MILK Mineral Complex, Salt, Minerals (Magnesium, Iron, Zinc, Manganese, Fluoride, Selenium, Iodine, Copper, Molybdenum, Chromium), Vitamins (C, E, B3, A, B5, B7, B12, B9, D, B6, B1, K, B2), Stabilisers (Cellulose Gum, Guar Gum, Carrageenan), Sweetener (Sucralose). For Allergens - See ingredients in bold.May contain gluten, eggs, nuts, and peanuts.
Is Serious Mass Vanilla 5.4kg 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:
Effectiveness
How well the product delivers its claimed benefits, based on reviews and ingredient evidence.
Ingredient Quality
Bioavailable forms, clinically effective dosages, clean label, minimal fillers.
Value for Money
Price relative to ingredient quality, dosage count, and effectiveness.
Side Effects Profile
Higher score = fewer side effects. 100 means virtually no adverse reactions reported.
Certifications & Testing
Third-party lab testing, GMP certification, and independent quality verification.
Overall Score
Weighted combination of all factors. Our bottom-line recommendation.
How Does Serious Mass Vanilla 5.4kg Compare?
See how this product stacks up against the top-rated mass gainers in our database.
| Product | Score | Price |
|---|---|---|
| Serious Mass Vanilla 5.4kg (this) | 62.0 | £52.95 |
| 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 Vanilla 5.4kg worth buying in 2026? ▼
What is the best price for Serious Mass Vanilla 5.4kg in the UK? ▼
What are the pros and cons of Serious Mass Vanilla 5.4kg? ▼
Is Serious Mass Vanilla 5.4kg third-party tested? ▼
How does Serious Mass Vanilla 5.4kg compare to Critical Mass Professional Lean Mass Gainer Banana 2.4kg (16 Servings)? ▼
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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