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10 Best Weight Gainer in The UK

Last updated on 09/07/2025

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Best Choice

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

6% Off

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

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Why We Love It

Enhances muscle mass effectively.
Offers nutritional weight gain.
Delicious chocolate flavor.

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 chocolate flavour mass gainer contains natural cocoa, 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.

Atlas Nutrisport Super Weight Gainer Mass Gain 5kg / 5000g + Shaker (Chocolate)

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

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.

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

Dymatize Super Mass Gainer Strawberry 2943g - Weight-Gainer Powder + Carbohydrates, BCAAs and Casein

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Why We Love It

Supports muscle growth and maintenance.
Reduces tiredness and fatigue.
Quality assured for athletes.

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

USN Muscle Fuel Anabolic All-In-One Muscle Mass Gainer, Strawberry Flavour - 2kg, 54g Protein Powder, 5g Creatine Powder & 5g BCAA Powder For Maximum Muscle Growth, Post Workout Recovery Drink Mix

20% OffFree Shipping

Why We Love It

High protein content ensures growth.
Enhances physical performance substantially.
Includes industry-leading nutrition formula.

Main Highlights

USN Muscle Fuel Anabolic protein drink mix: High protein shake powder with Vitamins, Minerals, Carbohydrates, BCAAs, Amino Acids and Creatine. Premium dietary supplement designed to support muscle building
Premium women's and men's supplements: USN diet supplements offer proven benefits, when taken alongside a balanced diet and healthy lifestyle. Always consult a healthcare professional first
Mass gainer protein powder: Strawberry flavoured drink powder with 54g of premium quality protein, 77g of carbohydrates and 850mg of HMB to support muscle recovery, growth and performance
Reach your goals: All in one muscle gain building stack, combined with raw creatines and carbohydrates, so creatine is easily absorbed and transported around the body. Easy to mix with water
Ultimate Sports Nutrition: USN are at the forefront of sports nutrition research, making effective sports nutrition supplements for professional and non-professional athletes, pre or post workout

Boosts mass for hard gainers.
High calorie for weight gain.
Gourmet taste adds joy.

Main Highlights

Extreme Calorie Load | Delivers up to 2,540 calories per day when mixed with 1% milk — engineered for hardgainers and those with extreme muscle growth goals.
High-Quality Protein Blend | Contains 92 g of protein from fast, medium, and slow-digesting whey sources to support muscle growth and recovery.
Complex Carb Matrix | Packed with 510 g of carbohydrates per 2 servings from whole food-based sources like waxy maize, sweet potato, and maltodextrin to fuel intense workouts.
Loaded with BCAAs & Glutamine | Provides 17.3 g of key amino acids (L-Leucine, L-Isoleucine, L-Valine, and L-Glutamine) to support recovery and protein synthesis.
Enzyme Fortified | Includes a digestive enzyme blend (Lactase & Protease) to help improve nutrient absorption and ease digestion of this dense shake.

Optimum Nutrition Gold Standard 100% Whey Muscle Building and Recovery Protein Powder With Naturally Occurring Glutamine and BCAA Amino Acids, Extreme Milk Chocolate Flavour, 28 Servings, 896 g

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Why We Love It

Supports muscle gain and recovery.
Low in sugar and fat.
Variety of flavors available.

Main Highlights

Optimum Nutrition’s Gold Standard 100% WHEY is the world’s best-selling protein powder* designed to support your fitness journey from day one
FAST-ABSORBING whey protein with whey protein isolate as the main ingredient helps with muscle gain and supports recovery* after every training session
The ON whey protein formula is Informed Choice certified, contains naturally-occurring BCAAs and GLUTAMINE and is LOW IN SUGAR and fat
Available in a VARIETY OF SIZES and FLAVOURS: double rich chocolate, banana cream, vanilla ice cream, unflavored protein powder and more
EASY & CONVENIENT: mix one scoop in 180-240 ml of cold water; best enjoyed in the morning or/and during the 30 minutes just before or immediately after training

8.8

Excellent

We scanned 263 products

We reviewed these offers relevant to the Weight 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, Atlas Nutrisport, The Bulk Protein Company, Myprotein, Dymatize, Mutant, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Weight 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 Dutch Chocolate 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 Weight Gainer and the best cost-to-value ratio is USN Muscle Fuel Anabolic All-In-One Muscle Mass Gainer, Strawberry Flavour - 2kg, 54g Protein Powder, 5g Creatine Powder & 5g BCAA Powder For Maximum Muscle Growth, Post Workout Recovery Drink Mixat USN with a 20% discount.
Our list of the best Weight 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 Weight Gainer in The UK

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We scanned 263 products

We concluded that: