10 Best Gainer in The UK

Last updated on 11/08/2025

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Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer with Vitamins, Creatine and Glutamine, Chocolate, 16 Servings, 5.45 kg

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Why We Love It

Supports muscle growth and performance.
Promotes muscle recovery after workouts.
Comes in 6 delicious flavours.

Main Highlights

Low fat mass gainer with over 1262 CALORIES and 50g of PROTEIN per serving to support muscle growth* plus 3 grams of CREATINE MONOHYDRATE to support performance**
No added sugar protein powder formula with 25 vitamins and minerals and less than 5g fat per serving, plus over 248 grams of CARBOHYDRATES helping support muscle recovery***
Serious Mass protein powder comes in 6 flavours (banana, chocolate peanut butter, chocolate, cookies & cream, strawberry and vanilla) & contains sweetener
To prepare weight gainer mix 2 scoops with 710 ml of water or plant milk, add fruit or nut butters for a tasty and calorific post workout or between meals protein smoothie
Source EFSA Journal *2010;8(10):1811; 2011;9(6):2203; ** 2011;9(7):2303; ***2011; 9(7):2303

USN Hyperbolic Mass Strawberry Cheesecake 6kg: High Calorie Mass Gainer Protein Powder for Muscle Building and Weight Gain - Improved Formula & Flavour with 7.5g Creatine Monohydrate and Less Sugar

Why We Love It

Uncompromised taste with muscle mass.
High calorie for quick results.
Nutrition-rich performance booster.

Main Highlights

Our best mass gainer yet: Our best-tasting mass gainer is for those who want to increase their muscle mass, but don't want to compromise on the taste of their protein drink.
High calorie bulk powder: With up to 1183 calories our all-in-one mass and weight gainer is ideal for individuals who struggle to gain muscle mass and want a fast-acting, easy-mixing and effective formula.
Amazing taste, great results: The improved formula of our delicious strawberry flavour mass gainer provides a greater post-workout effectiveness, with a smoother taste - all delivered with less Sugar.
A weight gainer with nutrition: Our mass protein powder contains a massive 60g of protein per serving, partnered with 7.5g of Creatine and 18 vitamins and minerals (B12, B6, C, Magnesium, Iron) to help you be at your best.
For best results: To get the best results from Hyperbolic Mass, take 1 servings daily, either after training or as a snack between meals. Simply mix 4 scoops (300g) of the protein powder with 900ml of cold water and enjoy.

Applied Nutrition Original Critical Mass - Weight Gainer with MCT Powder, High Calorie Protein Powder Mass Gainer (6kg - 25 Servings) (Chocolate)

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Why We Love It

Ideal for hard gainers' needs.
Quick digestive Waxy Maize Starch.
Four exciting and delicious flavours.

Main Highlights

PERFECT FOR HARD GAINERS: Original Mass weight gain protein powder is perfect for hard gainers who struggle to put on weight and gain mass. Using a mass gainer powder helps to ensure that growing muscles get the vital nutrients they need to recover and develop.
WAXY MAIZE STARCH: This serious mass protein powder uses Waxy Maize Starch, which is revolutionary because it bypasses the stomach and goes straight to the intestines for digestion. It replenishes glycogen stores faster than traditional sources of carbohydrate.
HIGH IN CALORIES, PROTEIN AND CARBOHYDRATES: This muscle gain protein powder makes a delicious shake that is high calorie, high protein and high in carbohydrate. This can be used as a high carbohydrate meal in the day or after a strenuous training session.
4 DELICIOUS FLAVOURS: Original Mass comes in 4 tasty flavours so you have a delicious addition to your training regime. You can order either banana, chocolate, strawberry or vanilla mass gainer protein powder to find your favourite flavour.
TESTED FOR ATHLETES: Applied Nutrition ensure that their protein powder mass gainer is extensively tested so that it meets the exacting standards of professional athletes. They are used by some of the world’s most elite athletes as part of their training.

XL Nutrition Xtra Mass 5.2kg Mass Gainer - Serious Mass Protein Powder - 50g Protein, 1000 Calories, Creatine Monohydrate, BCAA, Glutamine - 20 Servings, Strawberry Flavour

Why We Love It

Packed with 1000 extra calories.
Enriched with 172g carbohydrates.
Boosted with 50g protein.

Main Highlights

Extra calories for muscle growth: This weight gainer provides 1000 calories per serving, ideal for those seeking serious mass protein powder options. It offers a convenient shake alternative to meet your caloric intake goals efficiently.
Carbs for energy: With 172g of carbs per serving, this weight gain protein powder supports your body's energy needs. It's a key component in our mass protein powder, fueling your workouts and aiding digestion.
High protein content: Delivering 50g per serving, this is the best protein powder for muscle gain. It supports muscle repair and growth, making it an essential part of any bulking protein powder regimen.
Enriched with BCAA's and glutamimne: Loaded with BCAAs and glutamine, this 5kg protein powder helps reduce muscle soreness and fatigue, supporting muscle gain and recovery post-workout. It's a top choice for serious mass.
Creatine for stregnth: Added creatine mono hydrate makes this bulk pure whey protein powder perfect for doubling your strength and lean muscle gains, enhancing the effectiveness of your gym protein powder routine.

Kinetica Sports OatGain Weight Gainer - Chocolate Caramel Flavour | 620 Cal, 47g Protein & 78g Carbs/Serve, 15 Serving/2.4Kg | Optimum Grass Fed Protein Supplement | High Calorie & Easy Mixability

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Why We Love It

Delicious Chocolate Caramel Nut.
Easy to mix.
Repairs muscles, replenishes energy.

Main Highlights

Irresistible Flavour for Maximum Enjoyment: Kinetica Sports OatGain Mass Gainer comes in two mouthwatering flavours: Chocolate Caramel Nut and Raspberry Yoghurt. Each delivers a rich, satisfying taste and aroma, making it easy and enjoyable to fuel your body with extra calories and nutrients to support high training loads.
Smooth & Easy Mixability: Experience hassle-free mixing with Kinetica Sports OatGain Weight Gainer. Whether you prefer water, milk, or milk alternatives, our mass gainer powder mixes easily with milk or water for a high protein, high calorie shake in seconds.
High-Calorie Fuel for Muscle & Energy: Each serving of Kinetica Sports OatGain mass gainer provides 600+ calories and 46g of protein to help you gain weight, increase overall muscle mass and replenish your energy stores, making it ideal for intense workouts and recovery. Kinetica Sports Oatgain mass gainer contains only 6.4g of sugar per serving.
Convenient & Versatile for Any Lifestyle: Kinetica OatGain weight gainer is perfect for anyone looking to intake a high volume of calories for weight gain or energy regeneration. It’s suitable for vegetarians and can be used as a post-workout shake, meal replacement, or mid-day snack. Simply mix one serving with water, milk, or your preferred beverage for a quick and nutritious option.
Quality Assured & Batch-Tested for Safety: Kinetica Sports OatGain mass gainer is batch-tested under the Informed-Sport testing program to ensure that every batch complies with WADA’s high standards. You can trust that OatGain is free from banned substances and made with quality ingredients to fuel your training safely and effectively.

Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer with Vitamins, Creatine and Glutamine, Vanilla, 8 Servings, 2.73 kg, Packaging May Vary

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Why We Love It

Boosts muscle growth and performance.
Supports muscle recovery effectively.
Delicious variety of flavours.

Main Highlights

CALORIE RICH PROTEIN SOURCE – the ultimate gainer powder which can be used post-workout or between meals
SUPPORTS SERIOUS SIZE – great for those aspiring to be bigger, for those who find it hard to gain weight / muscle, or for those on the go who have high caloric needs due to intense training
1,255-1272 CALORIES per serving – when mixed with water
50 g – 53 g PROTEIN per serving
250 g+ CARBOHYDRATES per serving
ADDED CREATINE, L-GLUTAMINE & GLUTAMIC ACID
INSTANTISED POWDER – helps the powder dissolve easily and mixes well in a blender with other ingredients such as fruit and nut butters for added calories
24 VITAMINS & MINERALS per serving
NO ADDED SUGAR
AVAILABLE IN 6 LB TUBS OR 12 LB BAGS

Myprotein Impact Whey Weight Gainer Protein (2.5kg (Pack of 1), Chocolate Smooth)

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Why We Love It

Promotes healthy weight gain.
Provides high-quality protein.
Convenient and redesigned packaging.

Main Highlights

31g of protein
50g of carbs
388 calories per serving

Applied Nutrition Critical Mass Professional - Weight Gain Protein Powder, High Calorie Weight Gainer, Lean Mass (2.4kg - 16 Servings) (Chocolate)

27% OffFree Shipping

Why We Love It

High-quality lean mass gainz.
New formula with whey isolate.
Tested for athletic assurance.

Main Highlights

THE UK'S MOST TRUSTED MASS GAINER FOR SERIOUS SIZE & STRENGTH – Critical Mass Professional is the ultimate high-calorie weight gainer, engineered for those who want to bulk up, increase muscle mass, and fuel intense workouts. This mass gainer supplement is trusted by hard gainers, bodybuilders, and athletes looking for serious results.
1,000+ CALORIES PER SERVING – PACKED WITH HIGH-QUALITY PROTEIN & CARBS – Delivers a caloric surplus essential for lean muscle gain. Each serving contains a blend of fast-absorbing and slow-digesting proteins, including ISO-XP Whey Isolate, to maximize muscle recovery and growth. Combined with a premium carbohydrate complex, it helps sustain energy levels and support muscle glycogen replenishment.
POWERFUL CREATINE & GLUTAMINE COMPLEX FOR PERFORMANCE & RECOVERY – Enhanced with Creatine Monohydrate, Critical Mass Professional boosts strength, endurance, and muscle power output for high-intensity training. Includes L-Glutamine & Glutamic Acid, key amino acids that aid muscle recovery, reduce fatigue, and support immune function.
OPTIMAL WEIGHT GAIN FORMULA FOR HARD GAINERS & ATHLETES – Whether you struggle to put on weight, need extra calories due to intense training, or want to bulk up, this high-calorie gainer provides the perfect macronutrient balance. Ideal as a post-workout shake, meal replacement, or between-meal supplement for continuous muscle fuel.
EASY MIXING & DELICIOUS FLAVOURS FOR MAXIMUM ENJOYMENT – Designed for convenience, this instantized protein powder mixes effortlessly in water or milk, creating a smooth, creamy texture with no lumps or grittiness. Available in 6 mouth-watering flavours: Chocolate, Banana, Vanilla, Chocolate Mint, Strawberry, and White Chocolate & Raspberry.
TESTED FOR ATHLETES: at Applied Nutrition we carefully select and monitor each product through our quality management system to bring you the highest level of assurance. Critical Mass Professional is no exception and is tested at an ISO 17025 accredited lab.

The Bulk Protein Company

The Bulk Protein Company, SERIOUS GAINZ - Whey Protein Powder - Weight Gain, Mass Gainer - 30g Protein Powders (Chocolate, 5kg)

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Why We Love It

Builds muscle with high protein.
Promotes mass gain effectively.
Offers excellent value for money.

Main Highlights

30g PROTEIN PER SERVING TO HELP BUILD MUSCLE - Protein Isolate powder that contains 30 grams of high quality Protein per serving. A convenient and easy way to help you meet your daily protein needs. Use after training to quickly heal micro-tears in muscle tissues, which speeds up recovery, reduces muscle soreness and leads to stronger and bigger muscles over time.
PUT ON SIZE AND GAIN MASS - With 468 lean calories per serving, Serious Gainz protein powder is ideal when BULKING. Use as part of a balanced diet to help add body mass and increase weight gain. Contains 81g of carbohydrates which will help your body absorb the protein within, turning it into muscle mass to help towards improving your overall body composition.
PROTEIN SHAKE THAT TASTES GREAT - Add 3 scoops of powder to 400-500ml of water or milk and mix well to create a great tasting Protein Shake! Can also be enjoyed in smoothies, with oats or when added to a pancake mix. Protein powders don't have to be boring, so we made 10 different flavours for you to choose from.
HIGH QUALITY WHEY PROTEIN - Whey digests quickly and is rich in branched-chain amino acids (BCAAs). One of these BCAAs, Leucine, plays a major role in promoting muscle growth and recovery after resistance and endurance exercise. When amino acids are digested and absorbed into your bloodstream, they become available for muscle protein synthesis, which is the creation of new muscle.
EXCELLENT VALUE 5kg TUB WITH 40 SERVINGS - With up to a month's supply of high quality protein powder, we offer great value for your money compared with other brands. We recommend one serving per day to consistently meet your daily protein goal. Consume immediately post-training on workout days and between breakfast and lunch on non-workout days. Comes with scooper for measurements.

Dymatize Super Mass Gainer Rich Chocolate 2943g - Weight-Gainer Pulver + Kohlenhydrate, BCAAs und Casein

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Why We Love It

High-quality protein benefits muscle growth.
Reduces tiredness and fatigue.
Assurance of highest product quality.

Main Highlights

OUR MASSIVE COMBINATION of creatine, carbohydrates, BCAAs and proteins provides valuable nutrients to meet the particular needs of your bulking phase
DEVELOPED SPECIALLY FOR BODYBUILDERS, hardgainers and powerlifters and their specific needs, Protein Weight Gainer provides appropriate calories and nutrients, especially in the bulking phase
EVERY SERVING of Super Mass Gainer provides up to 243 g of carbohydrates, 52 g of protein, 11–12 g of BCAAs and 3 g of fine Creapure creatine, as well as five vitamins to help reduce tiredness
ACCORDING TO INFORMED CHOICE, every substance in the Mass Gainer powder is of the highest standard, so athletes can rest easy knowing their product is top quality, especially during competitions
FOR BEST RESULTS when bulking, mix one serving in 700 ml of water every day after training. The mass gainer protein shake is gluten free and suitable for vegetarians

8.7

Excellent

We scanned 263 products

We reviewed these offers relevant to the Gainer within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like Optimum Nutrition, USN, Applied Nutrition, XL Nutrition, Kinetica, Myprotein, The Bulk Protein Company, Dymatize, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Gainer in the market, we considered we took a deep dive into 1316 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is Optimum Nutrition Serious Mass Protein Powder High Calorie Mass Gainer with Vitamins, Creatine and Glutamine, Chocolate, 16 Servings, 5.45 kg. We love many things about this product by Optimum Nutrition. What sets it apart from the competition is Supports muscle growth and performance. , Promotes muscle recovery after workouts. , Comes in 6 delicious flavours.
The best value product for most shoppers and where user satisfaction is continuously the highest is USN Hyperbolic Mass Strawberry Cheesecake 6kg: High Calorie Mass Gainer Protein Powder for Muscle Building and Weight Gain - Improved Formula & Flavour with 7.5g Creatine Monohydrate and Less Sugar by USN based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Gainer and the best cost-to-value ratio is Applied Nutrition Critical Mass Professional - Weight Gain Protein Powder, High Calorie Weight Gainer, Lean Mass (2.4kg - 16 Servings) (Chocolate)at Applied Nutrition with a 27% discount.
Our list of the best Gainer is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best Gainer in The UK

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We scanned 263 products

We concluded that: