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Best Mass Gainer – UK Reviews

If you’ve ever been in a supplement store, you’ve probably seen tubs of mass gainer near the protein powders. The two types of supplements are similar because they both contain a large amount of protein, but they play different roles in your training.

As you can probably guess by the name, mass gainers are essentially protein powders with added carbs and fat to provide extra calories. These weight gainers are best utilised during your bulking phase when you are trying to build some serious muscle mass, but you can also use them as meal replacements during your maintenance and cutting phases.

Huge bodybuilder having a mass gainer shake

It can be daunting to know how to incorporate a new supplement into your diet, which is why we’ve broken down everything you need to know about finding the best mass gainers.

Keep reading to find out how they are great if you are a hard gainer and help you pack on muscle mass – as well as finding out which are the best on the market in the UK.

Editor’s Choice
USN Hyperbolic Mass All-In-One Gainer

USN Hyperbolic Mass All-In-One Gainer



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Best Budget Buy
Optimum Nutrition Serious Mass

Optimum Nutrition Serious Mass



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The Protein Works Total Mass Matrix

The Protein Works Total Mass Matrix

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MuscleTech Mass Tech

MuscleTech Mass Tech

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BSN True Mass 1200

BSN True Mass 1200



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Note: There’s a lot more information below but clicking the above links will take you to current prices, further information and customer reviews on Amazon or Best Gym Equipment.

A Detailed Look at the Best Weight Gainers

There are tons of high calorie mass gainer supplements on the UK market so it can be difficult to know which one you should buy. We’ve broken down some of the most popular powders on the market so that you can spend your time in the gym instead of on your laptop.

USN Hyperbolic Mass All-In-One Gainer comes in both 2 kg and 6 kg containers. Each serving contains 1160 calories and 60g of protein. It’s certainly not the cheapest mass gainer, but it contains more protein than most other brands. It also has added creatine to aid your training.

The scientifically designed formula should help you gain weight no matter how high your metabolism.


Hyperbolic Mass All-In-One Gainer is described as a perfect shake to have post-workout. It costs more than the average mass gainer, but you’re getting a solid amount of protein.

Things We Like
  • 60 g of protein per serving
  • Contains creatine
Things we don’t like
  • A bit more expensive than average

Optimum Nutrition is one of the most recognizable brands on the market. Serious Mass is slightly cheaper than most other mass gainers. You can buy it in either a 2.27 kg or 5.45 kg container.

Each serving provides you with 50 g of protein, 250 g of carbohydrates and 1250 calories. Considering how many calories are in each scoop, the 21g of sugar is relatively insignificant.

Optimum Nutrition Serious Mass provides a full spectrum of vitamins and minerals that fulfil most of your micronutrient needs, and it makes a convenient meal replacement.


Overall, it’s hard to find much wrong with Optimum Nutrition’s mass gainer. It provides a lot of calories per serving at a cheaper than average price. Optimum Nutrition is a well-known brand name that’s been around for a while, so you know you’re getting a good product with this mass gainer.


Things We Like
  • Low in saturated fat
  • Relatively low in sugar
  • Contains creatine


Things we don’t like
  • Most calories come from carbs
  • Some users report it being heavy on their stomach


The Protein Works Total Mass Matrix is another high quality mass gainer that’s priced fairly reasonably and comes in five flavours. It’s designed with a 2:1 ratio of carbs to protein. Overall, it doesn’t contain as many calories as many of its competitors at just 495 kcal, but it has a high ratio of protein to carbs.

If you’re looking to clean bulk and want a mass gainer that’s basically a carb-boosted protein shake, this is a good option for you.


This is the lowest calorie shake on this list, but if you’re trying to put on weight slowly, it’s a good choice since it’s basically a protein shake with a boost of carbs. We would recommend it if you find it relatively easy to put on weight or have trouble staying lean.

If you find it difficult to put on weight, you may want to go with a more calorie-dense mass gainer.

Things We Like
  • Comes in a 2kg and 5kg size
  • A large portion of the calories comes from protein


Things we don’t like
  • High in saturated fat
  • A large portion of the carbs are sugar


Mutant Mass is a protein-dense mass gainer made from whey protein isolate, concentrate, and casein powder. It comes in both 2.27 kg and 6.8 kg bags. The 6.8 kg bag gives you great value for your money but, as with all of these sort of products, it might be worth buying the smaller bag to see how you get on.

Each scoop contains over 1000 calories with relatively little sugar compared to many of its competitors, so you can easily use it to replace a meal or to refuel your muscles after a workout.

The calorie-dense formula relies on carbs from whole-grains and starchy vegetables and helps you gain weight without spiking your insulin as much a sugar-dense mass gainers.


MUTANT mass provides a great value for the price, especially if you buy the 6.8 kg bag. Since the recommended servings are fairly large, you may want to consume two half-serving shakes throughout the day. It offers 56 g of protein, 192 g of carbohydrates and 12 g of fat per serving.

Things We Like
  • Fairly low in sugar for a mass gainer
  • Comes in a 6.8 kg bag, which provides great value
  • Contains mostly starchy carbs
Things we don’t like
  • Some users report it causing smelly farts
  • May cause digestive problems if you’re lactose intolerant

MuscleTech is another well-known brand that’s been around for a while. They’ve delivered a solid formula with this mass gainer. Most of the calories come from whole-grain sourced carbs like buckwheat and quinoa.

This is another mass gainer than makes a good choice as a meal replacement because it’s very low in sugar (9 g per serving). If you’re looking for a cheap mass gainer that’s low in sugar and saturated fat but offers 63 g protein, this is a great option for you.


Overall, MuscleTech’s formula looks pretty solid compared to other brands. It’s coming in at about a market-average price but has a weight gainer blend that’s high in protein and low in saturated fat and sugar.

Things We Like
  • Most of the protein comes from whey protein
  • Low in sugar (only 9 g per serving)
  • Low in saturated fat (4 g per serving)


Things we don’t like
  • Servings are smaller than some other mass gainers


BSN’s True Mass 1200 Weight Gainer comes in a 2.8 kg and 4.8 kg container. Each serving contains about 1248 calories and 54 g of protein. The company has been around since 2001 and formulated for athletes.

Most of the carbs come from maltodextrin which has a similar GI Index (effect on your insulin) as table sugar.

If you’re looking for a mass gainer that’s essentially a whey shake with added carbs this might be a good choice for you.


BSN’s mass gainer is a solid product. Our biggest complaint is that it’s filled with maltodextrin which causes a larger insulin spike than mass gainers filled with starchy carbs from grains or vegetables.


Things We Like
  • Most of the protein comes from milk protein
  • The ratio of the macronutrients makes it a good post-workout drink


Things we don’t like
  • May be hard to mix
  • More expensive than average


History of Mass Gainers

People have taken supplements to improve athletic performance since at least the time of Ancient Greece when it was common practice for athletes to eat large amounts of meat and wine. However, modern muscle building supplements didn’t begin to gain momentum until the 1970s.

When mass gainers first hit the marker, little thought was given to the ingredients. They were often loaded with sugar, low-quality protein, and saturated fat.

Now that people are more aware that chronically eating too much sugar can lead to health complications such as diabetes and increased body fat, modern mass gainers contain far less sugar than they used to.

Many supplements now add calories using starches extracted from grains like quinoa, buckwheat, and rice because they cause smaller spikes in your insulin levels.

What is a Mass Gainer?

A mass gainer (AKA weight gainer) is simply a powder supplement that contains a high calorie count. The primary advantage of taking a mass gainer compared to getting all of your calories through food alone is the convenience they offer. You can often get the same number of calories in a serving of mass gainer as you can in 10 bananas.

Do you need to take a mass gainer if you want to be a competitive bodybuilder?

Like with any supplement, taking mass gainer shouldn’t be a substitute for training hard and eating a well-rounded and healthy diet, but it can be another tool to help you maximize your gains.

For people who have an ectomorphic body type (meaning they’re naturally thin and have trouble building muscle), bulking can be the most challenging part of training. If this sounds like you, you may have to eat even when you’re not hungry to continue making gains. Taking a mass gainer supplement may make this easier.

Experienced lifters may also notice they plateau and have trouble building weight. As you build muscle, your resting metabolism rises, which means you need to continue to increase your daily calorie intake or you’ll stop building new muscle.

Putting on weight is basic maths. If you want your weight to increase, you need to consume more calories than your body is burning. Different macronutrients have slightly different metabolic values, but if you’re a 100kg male eating 2,500 calories a day, you’re not going to gain weight no matter what your ratio of fat to carbs to protein is.

If you want to put on a pound per week, aiming to increase your calorie intake by about 500 calories per day is a good place to start. If you aren’t hitting your weight goal, you can up your calories a little more.

How Do Mass Gainers Differ from Protein Powder Supplements?

While both protein powders and mass gainers help with muscle growth, the main difference is the total number of calories they contain.

Protein supplements generally contain 20-30g of protein and 200 calories or less per serving. Whey protein concentrates are usually around 80% protein by dry weight whereas whey isolates may be made up of 90% protein or more.

Many mass gainers contain 50 or more grams of protein while packing more than 1000 calories.

If you were to make a post-workout shake with whey isolate, 2% milk, and a cup of fruit, it would probably still contain less than 300 calories. If you were to substitute out the whey for a mass gainer, it might contain 1200 calories or more.

Using Mass Gainers During Your Bulking Phase

When you’re in a phase of your training where you’re trying to gain weight, there are two different strategies you can you use: clean bulks and dirty bulks.

Clean bulking involves eating the same ‘clean’ foods that you do during your cutting and maintenance phases, but you either increase your meal frequency or portion sizes. Clean bulking has its pros and cons. You likely won’t put on weight as fast as you would with a dirty bulk, but you are much more likely to build lean muscle mass rather than also pile on the fat.

You can probably guess by that name dirty bulking involves eating basically anything you want: fried chicken, tubs of ice cream, entire pizzas. You can see a significant weight gain on a dirty bulk, but the increased amount of carbohydrates and processed fats means you’ll likely put on significantly more fat.

For most people, the fastest you can hope to gain muscle is about 0.1-0.2 kg per week (perhaps up to 0.5 kg per week if you’re a beginner). You may notice the scale increasing faster than this. However, those quick gains are usually caused either from adding fat or storing more water.

When you’re choosing a mass gainer, you should consider what type of bulk you’re going to do. If you want to stay strict with your dieting, choosing a mass gainer that’s relatively low in sugar will help keep down your body fat. After all, while we accept a bit of an increase in body fat during this phase the main goal is obviously to build muscle mass.

A mass gainer filled with sugar and lower quality ingredients may not keep you as lean but will be easier on your wallet and more suited to a dirty bulk.

What to Look for in a Good Mass Gainer

There are a lot of mass gainers on the market. Some can help you move toward your body goals while others aren’t worth your money.

The most important things to look at are the quality of the protein, the carbohydrate source, and the amount of saturated fat.

Always make sure that you look at the macronutrients and amount of sugar when choosing a mass gainer.

The amount of sugar or fat in each mass gainer varies widely. Some products may use starches from whole-grain almost exclusively while others are basically just protein shakes with a ton of added sugar.

If you’re going to take your mass gainer post-workout, a little extra sugar may help drive protein to your muscles by increasing insulin. However, if you plan on taking your shake in the middle of the day, you probably want to find one with a more conservative amount of sugar.

Some mass gainers may even contain additional ingredients that help you indirectly build muscle like creatine monohydrate.

Creatine is one of the most widely studied supplements and research consistently shows that it can increase muscle and power output by increasing your work capacity. If you plan on taking creatine, finding a mass gainer with creatine in it will reduce the number of supplements you need to buy.

Mass Gainer – Pros and Cons

Mass gainers allow you to easily add calories to your diet so that even if you’re clean bulking you can basically follow the same diet you were using during your other phases. For example, if during your maintenance phase you take in 3,500 calories per day, you could add one mass gainer shake to your diet each evening to achieve more than 4,000 calories.

They can also help you keep your shopping bill down. You can easily get 1,000 calories or more in a single serving and might cost you less than a cup of coffee.

You can also use weight gainers to cut down on your meal prep. You shouldn’t start skipping all your meals but replacing one meal a day with a mass gainer could save you time each morning or evening.

There are also a few reasons why you might want to avoid them.

If you rely too heavily on them, you’ll likely reduce the number of natural foods you eat per day.

Mass gainers also have a reputation for not tasting the best. While you’ll probably never find a mass gainer that tastes as good as a freshly baked apple pie (even if that’s the name of the flavour), you should be able to find one that’s at least tolerable.

Many can also be high in saturated fat. Even though researchers are beginning to think saturated fat might not be as damaging to your cholesterol and heart health as once thought, it still may be a good idea to not go overboard with the saturated fat intake until researchers fully understand how it affects your health.

How and When to Take a Mass Gainer

Because most mass gainers have a high carbohydrate content, you generally want to take them around your workout. However, you can also use them as a meal replacement throughout the day.

Note that they are pretty heavy on your stomach, so you likely don’t want to consume immediately before a workout.


If putting on weight is difficult for you, we recommend Hyperbolic Mass. It packs 1250 calories per serving. Even though its price is around the market average, it provides you with creatine and it’s fairly low in sugar.

Optimum Nutrition’s Serious Mass also packs a serious punch, contains creatine but is the more budget option.

If you find gaining weight is easy for you but have trouble staying lean, you may like Protein Works Total Mass Matrix. It contains fewer calories than most mass gainers in the uk, but it contains a high ratio of protein to carbs, which essentially makes it a carb-boosted protein shake.

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Jason Barnham

Jason started lifting weights back in 1990 which sparked his interest in Nutrition. He went back to college in 1993 then started at the University of Surrey in 1994, graduating in Nutrition and Dietetics in 1998.

Having worked in both the NHS and running his own dietetic clinic, he has now settled into the web publishing world.

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