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Mass gainers ranked

Top 10 Mass Gainers

For higher-calorie shakes, hard-gainer routines and easier surplus planning. We compare mass-gainer and high-calorie protein options for UK shoppers, focusing on calories, protein, serving size and whether the product genuinely fits a weight-gain routine.

Updated 27 April 2026Reviewed by Jamie, EditorContains affiliate links

Ranked on routine fit, label clarity and overall value — never by paid placement.

Explore the rankingCompare our top 3
Ranked list

The top 10 at a glance

Use the cards below to compare the products, then open the top-three table if you want the quickest side-by-side view.

Top pickSecond pickThird pickCompare our top 3
Nutrition data standard: Exact protein, calorie, caffeine and supplement amounts are shown only where this audit found a current source match. Anything still marked “Check label” was deliberately withheld rather than guessed. Last source check: 2026-04-29; always confirm the live product label before buying.
1
Optimum Nutrition Serious Mass
Optimum Nutrition

Serious Mass

Start hereCalorie surplus

A big-calorie mass gainer for people who genuinely struggle to eat enough food.

  • FormatPowder
  • Protein / serving50 g
  • Calories / serving>1,250 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: Serious Mass is the classic benchmark: high calories, large servings and a clear bulking purpose.

Watch-out: The serving is substantial, so check how it fits your stomach and daily calorie target.

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2
Serious Gainz Mass Gainer
The Bulk Protein Co.

Serious Gainz

Good valueCalorie surplus

A lower-calorie gainer-style option for shoppers who want extra calories without going straight to a mega serving.

  • FormatPowder
  • Protein / serving30 g
  • Calories / serving468 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: Serious Gainz may suit people who want a more manageable shake alongside meals.

Watch-out: Check whether the calorie level is enough for your goal; it is not as heavy as the biggest gainers.

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3
Reflex Instant Mass Heavyweight
Reflex Nutrition

Instant Mass Heavyweight

Also compareCalorie surplus

A heavyweight gainer for people who want a serious calorie and protein shake.

  • FormatPowder
  • Protein / serving60 g
  • Calories / serving1,000+ kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: Reflex sits closer to the big-serving end of the category, useful if you want a proper mass-gainer routine.

Watch-out: Large servings can be hard to drink daily, so do not buy purely on headline calories.

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4
USN Muscle Fuel Anabolic
Calorie surplus

A muscle-gain powder with a stronger sports-nutrition feel and a fuller formula.

  • FormatPowder
  • Protein / serving54 g
  • Calories / servingCheck label

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: USN is useful if you want protein, carbs and extra formula support in one shake.

Watch-out: Check whether you want a mass gainer or a more complex all-in-one product.

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5
SCI-MX Total Mass
Calorie surplus

A more moderate gainer option for people who want extra calories without an extreme serving size.

  • FormatPowder
  • Protein / serving32 g
  • Calories / serving478 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: SCI-MX may fit shoppers who want a bulking shake but still need it to be manageable day to day.

Watch-out: Compare calories per serving carefully; moderate gainers can require more food around them.

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6
Serious Protein 4kg Banana
The Bulk Protein Co.

Serious Protein

Calorie surplus

A protein-focused powder that is lighter than most true mass gainers in this ranking.

  • FormatPowder
  • Protein / serving24 g
  • Calories / serving114 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: It could help with protein intake, but it is not the obvious choice if your main problem is getting enough calories.

Watch-out: For bulking, check calories first rather than just protein.

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7
Optimum Nutrition Gold Standard 100% Whey
Optimum Nutrition

Gold Standard 100% Whey

Calorie surplus

A reliable whey protein, but it is more of a lean protein powder than a mass-gainer product.

  • FormatPowder
  • Protein / serving24 g
  • Calories / serving<120 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: It may suit people who want to add protein while keeping food as the main calorie source.

Watch-out: If you need easy calories, a dedicated mass gainer will make more sense.

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8
Dymatize ISO100 Hydrolyzed Whey
Calorie surplus

A lean isolate-style protein powder rather than a calorie-heavy gainer.

  • FormatPowder
  • Protein / serving25 g
  • Calories / serving<116 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: ISO100 is useful for contrast: high protein, lighter calories and a very different use case from Serious Mass.

Watch-out: Do not choose this expecting weight-gainer calories.

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9
PhD Diet Whey Lean Protein
Calorie surplus

A diet-leaning whey product that does not naturally belong at the heavy gainer end.

  • FormatPowder
  • Protein / serving20 g
  • Calories / serving<125 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: It may work for people who want protein support without a big calorie load.

Watch-out: For a surplus, check whether the calories are enough before buying.

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10
Optimum Nutrition Platinum Hydro Whey
Optimum Nutrition

Platinum Hydro Whey

Calorie surplus

A premium-style whey option with more protein focus than mass-gainer focus.

  • FormatPowder
  • Protein / serving30 g
  • Calories / serving<142 kcal

Source checked: Verified figures were matched to a current brand page, retailer nutrition table or pack claim on 2026-04-29. Any remaining “Check label” field was deliberately withheld rather than guessed.

Editor’s take: Platinum Hydro Whey is a useful comparison if you want quality protein, not a high-carb bulking shake.

Watch-out: It is unlikely to solve calorie intake on its own.

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Top-three comparison

Compare our top 3

A quick side-by-side view of the first three products in the ranking. Always check the live product page before buying.

Comparison point🥇 Optimum Nutrition Serious Mass🥈 The Bulk Protein Co. Serious Gainz🥉 Reflex Nutrition Instant Mass Heavyweight
Serving basisHigh-calorie ON servingCheck labelHeavyweight serving
Protein / serving50 g30 g60 g
Calories / serving>1,250 kcal468 kcal1,000+ kcal
Carbs / serving251 g81 g201 g
Why compare itHighest-calorie benchmarkLarge-tub value optionVery high-calorie serving
AmazonView on AmazonView on AmazonView on Amazon

Label check: Comparison figures can vary by flavour, serving size, formula and pack. Use this table as a shortlist, then confirm the current product label or live listing before buying.

FAQs

Common questions

Plain-English answers to the checks that usually matter before buying.

What makes a good mass gainer?

A good mass gainer typically has a high calorie content and a balance of protein and carbohydrates. Check labels for serving size and ingredients.

Will it make me fat?

Mass gainers are calorie‑dense. Consider your overall calorie needs and goals when adding them to your diet.

When should I drink it?

People incorporate mass gainer shakes at different times, such as post‑workout or between meals, based on their routines. Follow the serving suggestions on the label.

Do I need a blender?

Some mixes are very thick — a blender is helpful, but many shake up fine with water or milk.

Next step

Planning a muscle-gain routine?

A mass gainer can help with calories, but the wider routine still needs protein, training structure and consistent meals.
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