10 Best Lean Mass Protein 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

Reflex Nutrition One Stop® Xtreme - Serious Mass Gainer - All in One Protein Powder - 55g Protein, 10.3g BCAAs, 5,000mg Creatine - Muscle Building Protein Shake (Vanilla Ice Cream, 4.35kg)

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Why We Love It

Optimal muscle-building protein blend.
Includes digestive enzymes, vitamins.
Grass-fed, hormone-free ingredients.

Main Highlights

All-in-One Weight Gainer To Simplify Your Supplement Routine: One Stop Xtreme has been formulated to replace the use of numerous supplements, allowing you to take only one protein shake to support muscle growth alongside a balanced healthy diet
High-performing Weight Gain Shake: One Stop Extreme high protein powder delivers a hit of protein, creatine, BCAAs and other beneficial nutrients to bodybuilders looking to make gains - contributing to the growth and maintenance of muscle mass
Boosting Stregth and Endurance: Reflex mass gainer protein powder contains creatine, that increases physical performance in successive bursts of short-term, high intensity exercise - With LAB2PRO friendly bacteria and Digezyme digestive enzymes
Nutritional Excellence: contains L-Leucine, Beta Alanine, Betaine Anhydrous and Taurine, along with essential vitamins and minerals aiding the maintenance of normal protein synthesis, function of the immune system and testosterone production
Premium Ingredients: Reflex only uses whey protein sourced from grass-fed cows, ensuring a high-quality weight gain protein powder that mixes well, with a smooth texture and a delicious taste
Produced in an Informed Sport Registered Facility: Suitable for vegetarians and Halal certified - Hormone-free, zero added sugars, artificial colors or soy protein, assuring a conscientious choice of food supplements for weight gain

The Bulk Protein Company

SERIOUS Protein – Protein Powder – 4kg – Low Carb – Supports Lean Muscle Growth – Recovery Supplement - The Bulk Protein Company - 133 Servings (Banana)

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Why We Love It

Promotes muscle growth and recovery.
Tastes great with various recipes.
Long lasting value pack.

Main Highlights

✅ 24g PROTEIN PER SERVING TO BUILD LEAN MUSCLE - A convenient way to help meet your daily protein needs. Use after training to quickly heal micro-tears in muscle tissues, speed up recovery and reduce muscle soreness for STRONGER and BIGGER muscles over time.
✅ HIGH PROTEIN, LOW CALORIES, LOW CARBS - Only 114 Calories Per Serving! Serious Protein powder is 80% Protein with Low Carbs, Sugars, and Fats. Ideal for adding LEAN MASS! Perfect to use as a meal replacement or part of a calorie-controlled diet, while trying to lean out, or for those simply looking to support MUSCLE GAINS.
✅ HIGH QUALITY INGREDIENTS - Premium blend of Whey Protein Concentrate, Micellar Casein and Soy Protein Isolate, a combination of slow and fast releasing proteins for total protein synthesis throughout the day. Also contains GLUTAMINE PEPTIDE, essential for muscle recovery and more bioavailable than regular glutamine, helping aid MUSCLE GROWTH.
✅ PROTEIN SHAKE THAT TASTES GREAT - Add 1 rounded scoop (30g) to 250ml of cold water or skimmed milk and shake well to create a great tasting Protein Shake! Can also be enjoyed in smoothies, with oats or when added to a pancake mix. For best results consume 1 serving (30g) one to three times per day
✅ EXCELLENT VALUE - More than 6 weeks supply in one tub, when following our recommended servings. Comes with scoop for measurements.

The Bulk Protein Company

Anabolic Gainz 5kg – Mass Gainer – 30g Protein Powder – Contains 3g Creatine Per Serving – Post Workout Recovery Fuel to Build Lean Muscle – 40 Servings – GMP Certified – TBPC (Chocolate)

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Why We Love It

Packed with protein and calories.
Supports muscle growth effectively.
Great taste and mixability.

Main Highlights

ANABOLIC GAINZ – Is a protein powder, designed to supplement muscle growth and to be consumed as a post-workout shake. We’re now available in the staple flavours, these are Chocolate, Strawberry, and Vanilla.
NUTRITIONALS – Our Anabolic Gainz Mass Gainer comes in a 5kg tub containing 30g of Protein and is packed with over 450 calories! In addition, we’ve added 3g of Creatine per serving to support muscle growth, recovery, and performance.
MACROs – Our shake contains Carbohydrates, Creatine, Amino Acids, Vitamins, and Minerals. It’s a great-tasting protein drink that will slot straight into your supplement stack.
40 SERVINGS – With over a month's supply this protein powder will help reach your goals. It mixes well and doesn’t require a blender, simply look out for our TBPC Gainz 800ml Shaker.
TBPC – Here at The Bulk Protein Company we're serious about value, huge protein levels, and incredible results in your training & diet. If you're serious about training, Anabolic Gainz is for you. GMP Certified, Manufactured in the UK.

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

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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

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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

Serious bulking support for trainers.
Delicious flavors enhance your intake.
High in protein promotes muscle growth.

Main Highlights

High Protein for Optimal Muscle Gain: Each 135g serving delivers 45g of high-quality protein along with 65g of carbohydrates, providing essential macronutrients required to support muscle growth, weight gain, and sustained energy levels throughout the day.
High-Calorie Formula to Support Bulking Goals: With 500 kcal per serving, this mass gainer is designed to help athletes, bodybuilders, and fitness enthusiasts meet their daily calorie requirements for effective bulking and muscle recovery.
An easy and convenient option for those looking to increase their calorie and protein intake, whether enjoyed between meals or after training as part of your daily routine.
Supports Muscle Growth The balanced blend of protein and carbohydrates aids in muscle repair and development after workouts, promoting muscle gain.
Delicious Flavours with Easy Mixing for Convenience: Available in a variety of popular flavours, this mass gainer mixes smoothly with water or milk, offering a convenient and enjoyable way to increase your calorie and protein intake any time of day.

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

TheHealthyTree Company

Organic Whey Protein Powder (600g) - Grass Fed Unflavoured Organic Protein Powder by TheHealthyTree Company - Low Carb Natural Protein for Muscle Growth & Recovery

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Why We Love It

Sourced from sustainable farming practices.
Ideal for post-workout recovery.
Promotes easy digestion.

Main Highlights

GRASS FED WHEY PROTEIN POWDER - Our organic whey protein powder is sourced from grass-fed, pasture raised cows in Germany, to the highest European Soil Association standards (DA25404). This ensures you're getting the best possible fuel for your body, while supporting sustainable farming practices.
UNFLAVOURED & NO ADDITIVES - Enjoy the natural, unflavoured creamy taste of our whey protein powder, which is perfect for mixing into your smoothies, shakes, and baking recipes. Unlike many alternatives, our whey is hormone free, gluten free, soy free, Non-GMO and has absolutely no sweeteners or added sugar - halle…MOO-jah.
80% PURE WHEY PROTEIN - Our organic protein powder contains a high concentration of naturally occurring amino acids and BCAAs. In addition to being a fantastic vegetarian protein source, it dissolves easily in water and is ideal for post-workout recovery and muscle growth.
THE RIGHT WAY TO WHEY - Use our protein powder organic to make great tasting low carb keto baking recipes like flapjacks and pancakes. In the morning or after the gym, just mix 1 or 2 tablespoons into your shaker with water, milk or nut milk. If you’ve got more time, blend with frozen fruit to make a delicious smoothie that’s packed with vitamins.
EASY DIGESTION - We’re proud to say that our whey passes through a leading ceramic microfiltration system to create the freshest, creamiest natural whey protein on the planet. Not only is it kinder to the environment, it dissolves well and is kind to your digestive system too, without the uncomfortable bloated feeling of some other protein powders.

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.

8.7

Excellent

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We scanned 928 products

We reviewed these offers relevant to the Lean Mass Protein 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, Reflex, The Bulk Protein Company, Applied Nutrition, USN, Bulk, TheHealthyTree Company, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Lean Mass Protein 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 Reflex Nutrition One Stop® Xtreme - Serious Mass Gainer - All in One Protein Powder - 55g Protein, 10.3g BCAAs, 5,000mg Creatine - Muscle Building Protein Shake (Vanilla Ice Cream, 4.35kg) by Reflex based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Lean Mass Protein 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 Lean Mass Protein 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 Lean Mass Protein Powder in The UK

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We scanned 928 products

We concluded that: