10 Best Weight Gain Powder in The UK

Last updated on 13/09/2025

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

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Why We Love It

Supports muscle growth and performance.
Healthy, low-fat, high-calorie content.
Six tasty, varied flavors.

Main Highlights

Low fat mass gainer with over 1250 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 250 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

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

Why We Love It

Perfect for hard gainers.
Replenishes glycogen stores faster.
Extensively tested for athletes.

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.
DELICIOUS FLAVOURS: Original Mass comes in 6 tasty flavours so you have a delicious addition to your training regime.
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.

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

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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.

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

3% OffFree Shipping

Why We Love It

Supports muscle growth and performance.
Promotes recovery with carbohydrates.
Offers tasty, diverse flavor options.

Main Highlights

Low fat mass gainer with over 1250 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 250 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

The Bulk Protein Company

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

13% OffFree Shipping

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.

Optimum Nutrition Gold Standard Whey Protein, Muscle Building Powder with Naturally Occurring Glutamine and Amino Acids, Double Rich Chocolate, 29 Servings, 899 g, Packaging May Vary

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Why We Love It

Supports muscle gain and recovery.
Certified, low-sugar protein formula.
Variety of sizes, flavors.

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.
*Source: Euromonitor International Limited; Consumer Health 2023 edition, Sports Protein Powder category, % retail value shares, 2022 data.
** Source EFSA Journal 2010;8(10):1811; 2011;9(6):2203.

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)

19% 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.

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

SCI-MX Ultra Mass XL - 4kg - High Calorie Muscle Mass Protein Powder - Chocolate - Muscle Growth & Weight Gain • 60g Protein + 1088 Calories per Serving + 5g Creatine

Why We Love It

Promotes muscle growth and recovery.
Enhances strength for optimal workouts.
Suitable for various fitness goals.

Main Highlights

⚡ FUEL YOUR MUSCLE GROWTH, WORKOUTS & RECOVERY WITH OUR ULTRA MASS. A scientifically developed high protein mass gainer formula for those looking to develop and maintain quality muscle. Multisource Carb Complex with 23 Essential Micronutrients & 5g Creatine Monohydrate per serving. Includes an impressive 60g of protein per serving, providing your body with the optimum and essential building blocks required for muscle growth and repair. Also available in Strawberry.
🏋️‍♂️ BENEFITS: This is a scientifically developed high protein mass gainer formula for those looking to develop and maintain quality muscle and meet calorie demands. Consuming sufficient calories for healthy weight gain made easy with carbs to provide your body with enough energy to workout and recover at your best. With an added 5g creatine which is proven to enhance your strength and power, allowing you to get the most out of your workouts. Suitable for Vegetarians.
🍦 HOW & WHEN TO USE: 6 x heaped scoops (300g) to 900-1200ml water. In the pursuit of achieving remarkable muscle development and conquering your weight gain goals, this is the perfect solution. Tailored to individuals facing the daunting challenge of consuming sufficient calories for healthy weight gain, this product stands as a beacon of promise. We only recommend 1 serving per day.
🧡 POWERING EVERY GOAL: Whether you want to build muscle, bulk, reduce body fat or peak your performance, our core focus is delicious, fitness-focused nutrition in the most fun and indulgent flavours. Our products are made to complement all types of training and performance goals – whether you’re a casual gym goer, an athlete or sportsperson, you can reap the benefits of our mouthwateringly delicious and flavoursome protein powders.
⭐ WHY SCI-MX: Our goal is to help nurture, support, and inspire the sportsperson in all of us. From recovery to competition training, there’s a SCI-MX product to help you achieve your goal. From high-quality protein powders, pre-workout and post-workout blends like creatine monohydrate to high-protein snacks such as flapjack bars, we've got you covered. Our no-nonsense approach to sports nutrition supplements guarantees you’ll always receive premium quality, great value products.

8.7

Excellent

We scanned 928 products

We reviewed these offers relevant to the Weight Gain Powder 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, Applied Nutrition, USN, The Bulk Protein Company, Myprotein, SCI-MX, 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 Gain Powder in the market, we considered we took a deep dive into 4641 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 Peanut Butter, 16 Servings, 5.45 kg, Packaging May Vary. We love many things about this product by Optimum Nutrition. What sets it apart from the competition is Supports muscle growth and performance, Healthy, low-fat, high-calorie content, Six tasty, varied flavors.
The best value product for most shoppers and where user satisfaction is continuously the highest is Applied Nutrition Original Critical Mass - Weight Gainer with MCT Powder, High Calorie Protein Powder Mass Gainer (6kg - 25 Servings) (Strawberry) by Applied Nutrition based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Weight Gain Powder 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 Gain Powder 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 Gain Powder in The UK

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We scanned 928 products

We concluded that: