Top 7 Best Mass Gainers in the UK 2023: Weight Gainer Protein Powder Reviews

A picture of Best Mass Gainer UK founder, personal trainer Andy Williams
Written By
Andy Williams
Last Updated on April 17th, 2024
Highest Protein Mass Gainer
A tub of mass gainer from Transparent Labs along with a shaker cup and scoop
Transparent Labs Mass Gainer
Best Weight Gainer For Skinny Guys
Two bags of Crazy Nutrition Mass Gainer
Crazy Nutrition Mass Gainer
Best Value Mass Gainer in the UK
A bag of Bulk Mass Gainer
Bulk Mass Gainer

Welcome to my 2023 roundup of the best mass gainers in the UK. Did you know that there are currently over 65 different weight gainers on the UK market? And did you also know that I’ve spent thousands of pounds trying and testing every single one of them?

The best mass gainers in the UK based on extensive reviews

Over the past 6 months or so, I’ve made it my mission to find the best weight gainer for men and anyone else who wants to increase their body weight and build muscle naturally.

But I’ve got to be honest; it’s been a hard task—and not just financially. You see, the average mass gainer is nothing more than some amino-spiked protein powder mixed with a bunch of maltodextrin, sugar, artificial sweeteners, and goodness knows what else.

I’ve spent the past 6 months of my life gulping down sickening shakes so that you don’t have to. What follows is a definitive list of the best mass gainers for skinny guys in the UK based on ingredient quality, taste, mixability, digestibility, and weight-gaining effectiveness.

Reviews of the Top 7 Best Mass Gainers in the UK For Building Muscle in 2023

Even though most weight gainers will do you more harm than good, there are still some top-quality mass gainers to be found if you know where to look.

These weight gainer reviews will help you find the best mass gainer protein powder for your specific weight-gaining goals and nutritional needs.

1. Crazy Nutrition Mass Gainer — Best Weight Gainer For Skinny Guys

Two bags of Crazy Nutrition Mass Gainer

If you just want to buy the very best weight gainer supplement for hardgainers, look no further than the market leader—Crazy Nutrition Mass Gainer.

Ranking #1 out of nearly 70 different UK weight gainers, Crazy Nutrition Mass Gainer gets top marks for its 100% clean ingredient list, incredible taste, and unrivalled muscle-building results.

With gluten-free oats and a combination of fast-acting and slow-release proteins, you can see why Crazy Nutrition Mass Gainer has helped gym-goers gain anywhere from 5 to 15 lbs of rock-solid muscle mass in just a few months.

Bags of Crazy Nutrition Mass Gainer in chocolate and Vanilla

This scientifically optimal weight-gaining formula boasts 40g of protein, 55g of carbs, and 10g of fat for a total of 488 mass-building calories per serving.

As if that wasn’t enough, this proven mass gainer is formulated with 5 important digestive enzymes so that your muscles can grow bigger by making the best possible use of all the nutrients that you’re consuming.

So if you want a safe and effective weight gainer with a proven track record of producing results, then check out my full Crazy Nutrition Mass Gainer review or click below for the best UK price.

  • Rated as the #1 UK mass gainer in our independent testing
  • Has the perfect amount of calories (488) for gaining muscle mass and bulking up
  • Triggers noticeable weight gain with 55g of clean, oat-derived carbohydrates
  • Contains an optimal 40g protein dose from fast-acting and slow-release sources
  • Tastes delicious (I’ve tried both flavours) and mixes better than any other weight gainer
  • A bit pricey unless you subscribe and save

2. Transparent Labs Mass Gainer — Highest Protein Mass Gainer

A tub of mass gainer from Transparent Labs along with a shaker cup and scoop

Even though Transparent Labs Mass Gainer is a US supplement—you can still get it shipped to the UK—I had to include it in my list of the top weight gainers because it’s too effective to ignore.

With 53g of grass-fed whey protein per serving, your muscles will naturally receive a massive hit of top-quality amino acids every time you drink this high-calorie mass gainer, helping them to grow larger in record time.

This third-party tested weight gainer also has 110g of carbohydrates from organic tapioca maltodextrin so that you can bulk up and gain weight without worrying about harming your health with cheap, sugary carbs.

And with 14g of healthy fats from MCTs, it’s no wonder that Transparent Labs Mass Gainer has a reputation as the best bulking protein powder that you can buy. Fats are crucial for hormonal health, and at 9 calories per gram, they’re extremely effective nutrients for gaining weight and muscle mass.

Photo of the Transparent Labs Mass Gainer scoop and tub

With such a healthy ingredient list, you’d be forgiven for thinking that this protein bulking powder tastes terrible. Actually, to my surprise, this supplement is one of the best tasting mass gainers that I’ve tried, probably because it’s completely free from artificial sweeteners, colourings, and preservatives. 

Although this supplement is far from the cheapest mass gainer, it’s definitely worth the price for those in the US who are looking for an A-grade high protein weight gainer. Feel free to read my full Transparent Labs Mass Gainer review to learn more, or just click below for the guaranteed lowest price.

  • Fuels weight gain with 750 quality calories per serving
  • Supports muscle growth with 53g of whey protein from grass-fed cows
  • Contains 110g of carbs from organic tapioca maltodextrin to help increase your body weight
  • Formulated with 14g of healthy fats from MCTs and coconut powder for balanced macros
  • 100% free from artificial sweeteners, colouring, and preservatives
  • Expensive (especially if shipping to the UK)

3. Bulk Mass Gainer — Best Value Mass Gainer in the UK

A bag of Bulk Mass Gainer

Even though Crazy Nutrition Mass Gainer steals the show, Bulk Mass Gainer is one of the best weight gainers in the UK for bulking up on a budget.

With thousands of glowing mass gainer reviews, this weight gainer from Bulk has a proven track record at producing real weight gain results for both recreational gym goers and elite-level athletes.

For less than the price of a meal for two at a mediocre restaurant, you can get a big 5kg bag of Bulk Mass Gainer, with each of the 37 servings providing you with 538 calories, 66g of carbs, 40g of protein, 9g of fat, and 8g of fibre.

The Bulk Mass Gainer scoop size

This maltodextrin free mass gainer utilises ultra-fine Scottish oats for its carbohydrates so that you can enjoy consistent energy that will help you power through your bulking workouts. A fantastic low-sugar mass gainer, this high-calorie weight gainer won’t spike your insulin and cause a big energy drop after you drink it because the 8g of naturally occurring fibre ensures that glycogen is released slowly, just as nature intended.

The combination of whey protein, milk protein (which is 80% casein), and egg protein means that you’ll gain weight faster while taking Bulk Mass Gainer because your muscles are receiving both fast-digesting and slow-release amino acids, enabling your body to remain in an anabolic (growing) state for much longer than usual.

See my Bulk Mass Gainer review to learn more, or scroll down for the lowest price (I update it daily).

  • Rated as the #1 best value mass gainer in the UK
  • Provides 538 clean, mass-building calories per serving
  • Has 66g of complex carbohydrates from oats for consistent energy levels
  • Provides a 40g blend of fast-digesting and slow-release protein for an optimised amino acid delivery
  • Doesn't contain any maltodextrin, soy, or filler ingredients
  • Comes with 8g of naturally occurring fibre for healthy digestion
  • The big 5kg bags are great value for money
  • Shakes are quite filling (a bit like a bowl of porridge)

4. The Protein Works Total Mass Matrix Extreme — Best Tasting Mass Gainer in the UK

Total Mass Matrix Extreme from The Protein Works

With a massive 962 calories per serving, The Protein Works Total Mass Matrix Extreme is the highest calorie weight gainer in my list of the best UK mass gainers.

Not only is Total Mass Matrix Extreme the most calorie-dense gainer, but it’s also the best tasting mass gainer in the UK, along with Crazy Nutrition. So if you want a weight gainer with a milkshake-like texture and indulgent flavours that give your taste buds a break from bland bulking meals, this is the supplement for you.

With a staggering 173g of carbs and 53g of protein, Total Mass Matrix Extreme is certainly a mass-building powerhouse that’s capable of helping even the hardest of hardgainers put on the size they desire.

Me pouring a serving of The Protein Works Total Mass Matrix Extreme into my shaker cup

Going a step further, The Protein Works has also formulated Total Mass Matrix Extreme with an optimal 5-gram dose of creatine monohydrate so that you can increase your strength and muscle fullness.

But if all of this sounds slightly too hardcore, then you can always get the regular Total Mass Matrix instead, which has around half the calories.

Also, if you don’t want any creatine in your mass gainer, you can see my post on the best weight gainer without creatine in the UK.

  • Rated as the best tasting mass gainer in the UK (out of over 60 weight gainers)
  • Has a massive 962 calories per serving for serious weight gain
  • Triggers muscle hypertrophy with a huge 53g protein serving
  • Contains 173g of carbs for workout energy and weight gain fuel
  • Formulated with an optimal 5-gram dose of scientifically-proven creatine monohydrate
  • Might be too calorie-dense for some people
  • Not everyone likes creatine in their gainer

5. MaxiMuscle Cyclone — Best Mass Gainer With Creatine in the UK

A tub of Cyclone by MaxiMuscle

If you’re looking for the best lean mass gainer in the UK, then look no further than MaxiMuscle Cyclone. I’ve been using this post-workout powerhouse for over 10 years at this point, and I’ve made some great gains while taking it (and so have my training clients).

Although Cyclone might not be a cheap mass gainer (unless you get it on sale), it’s definitely the best muscle gainer protein powder for making lean gains.

Each 204-calorie serving has 31g of protein, 10g of carbs, and just 1.6g of fat, enabling you to enjoy a shake that doesn’t sit heavy on your stomach or kill your energy levels.

Cyclone contains 3 types of whey protein—concentrate, isolate, and hydrolysate—so that your muscles receive a rapid influx of essential amino acids when they need them most.

Maxinutrition Cyclone tub, scoop, and shaker cup

And with 5g of creatine for increased strength, 1.6g of HMB for muscle preservation, and 10g of glutamine for faster muscle repair, you can see why Cyclone has a reputation for being the best weight gainer protein powder in the UK.

As I said in my MaxiMuscle Cyclone review, some people don’t consider this supplement an out-and-out weight gainer. However, given the mass-building potential of Cyclone’s ingredients, I definitely feel that it merits the award of the best protein powder for gaining weight, even if it’s not strictly a mass gainer.

  • Ranked as the #1 weight gainer with creatine in the UK
  • Has 31g of top-quality whey protein to speed up muscle repair and growth
  • Contains 10g of quality carbs for efficient post-workout glycogen resynthesis
  • Has a scientifically-optional 5-gram dose of creatine
  • Includes 1.6g of HMB for muscle preservation
  • Formulated with 10g of glutamine to reduce muscle soreness and fast-track workout recovery
  • Tastes amazing and mixes really easily
  • Quite expensive
  • Might not be enough calories for super hardgainers

6. Nature’s Best Weight Gainer — Highest Protein-To-Carbs Ratio

A weight gainer from Nature's Best

Although an unassuming supplement like ​​Nature's Best Weight Gainer might not appeal to the bodybuilding crowd, this powder is arguably the best mass gainer for skinny guys to bulk up because it has 40g of whey protein per serving, including 8.8g of naturally occurring BCAAs.

According to scientific research, 40g of whey is actually the ideal amount of protein for maximising muscle protein synthesis after a workout, so you can tell that Nature’s Best is really up on the latest nutritional science.

But the optimal dosages don’t stop there. Each serving of this top mass gainer contains 5g of creatine monohydrate so that you can develop stronger, fuller muscles and increase your body weight effectively.

Creatine is the most studied and reliable sports supplement on the planet, so you can be sure that you’re consuming only safe and effective ingredients when you get Nature’s Best Weight Gainer.

A mass gainer in a shaker bottle

This affordable mass gainer also has 34.8g of quality carbohydrates from oats and maltodextrin, with just 3.9g of sugar per shake. As such, your muscles will naturally benefit from both fast glycogen replenishment after a workout and slow-release energy during the day, helping you to be at your best and put on quality weight.

Add in the 1.5g of anti-catabolic HMB, which helps to prevent muscle protein breakdown, and it’s hard to argue with this product being the best mass gainer supplement for those seeking an affordable, all-in-one powder.

  • Has an astounding protein-to-carbs ratio for building muscle mass
  • Includes 35g of clean carbohydrates to help you gain weight safely
  • Provides 39.7g of premium whey protein per serving
  • Formulated with 5g of creatine to increase your muscle strength and fullness
  • Contains 1.5g of HMB to stop muscle loss in its tracks
  • Has less than 4g of sugar per serving
  • Some hardgainers might want more carbs than protein
  • Some people prefer to take their creatine separately

7. Serious Gainz Protein Powder — Cheapest Weight Gainer in the UK

A tub of Serious Gainz next to a shaker bottle

Despite being the cheapest weight gainer in the UK, Serious Gainz is definitely one of the best protein powders for weight gain and muscle growth.

A single, easy-mixing serving contains 468 calories, 81g of carbs, 30g of protein, and 3.5g of fat, helping you to create the calorie surplus that you need to increase your body weight.

Let’s break that down.

The carbs come from oat flour and maltodextrin, so you’re getting fast fuel for your workouts as well as that sustained energy to keep you feeling focused throughout the day.

And since you get both fast-acting and slow-digesting protein, your muscles get a big protein hit and also a sustained release of amino acids, enabling you to stay in an anabolic rather than catabolic state.

As I said in my Serious Gainz review, a big 5kg tub of this stuff costs about the same as one month’s gym membership in many places, so you’re getting excellent value for money with this cheap weight gainer.

  • Rated as the cheapest mass gainer in the UK
  • Contains an impressive 468 calories per serving
  • Includes 30g of protein and 81g of carbs for gaining muscle mass
  • Mixes really easily in any standard shaker bottle
  • A big 5kg gives you 40 servings
  • Very affordable compared to other mass gainers
  • Not all users liked the taste
  • Protein content isn’t as high as other weight gainers

How To Select The Best Weight Gainer Supplement in the UK

Now that you’ve seen my list of the best weight gaining shakes on the UK market, I’m going to show you how to find the best mass gainer shake for you.

After all, we all have different weight-gaining goals, so the best supplement for me might not necessarily be the best supplement for you (although there are a few mass gainers that you just can’t go wrong with).

Related Mass Gainer Reviews:

Know Your Calorie Requirement

Some of the best mass gainers for skinny guys in the UK to bulk up

Some people naturally have higher calorie requirements than others, meaning that they can benefit from a protein powder with high calories or a higher-calorie weight gainer.

High activity levels, fast metabolisms, and lots of room for muscle mass (i.e., novice lifters) all demand a higher calorie intake.

However, it’s not a case of the more calories, the better.

While mega-calorie gainers like Mutant Mass have been known to work, you often end up consuming a bunch of cheap carbs that make you fat, bloated, and seriously unhealthy.

Remember, a calorie surplus of around 500 calories per day is enough for most people to gain weight and get great mass gainer results. Therefore, if you get a gainer with way more calories than this, you might experience unwanted fat gain.

Understand What Makes a Good Weight Gainer

The absolute best mass gainers in the UK for gaining weight

After testing nearly 70 different mass gainers, I think I have a pretty good understanding of most supplement companies’ mentality when it comes to weight gainers.

Most brands give you the bare minimum for the highest possible price, and they spend more money on advertising than on formulating their supplements.


Yet, there are a few brands that really care about their customers’ health and results, and about making a positive impact in the world. So here’s what to look for.

In terms of ingredients, I recommend getting a mass gainer that uses oats as the primary carbohydrate source because oats provide more consistent energy than maltodextrin.

While I’m not completely against the use of maltodextrin in mass gainers, a lot of brands use too much and essentially rip you off on what is a very cheap carbohydrate to source.

So while oats are ideal, organic tapioca maltodextrin is a good alternative because it’s much healthier than the cheap wheat-derived maltodextrin that most companies use.

Additionally, while a whey-only gainer can absolutely work, I prefer mass gainers that have a mixture of fast and slow-digesting proteins so that I can get a more consistent supply of amino acids.

Related: USN Muscle Fuel Anabolic Review

Find Your Favourite Flavour

A selection of the best weight gainers for skinny guys in the UK

The best tasting weight gainer for me might not necessarily be the best tasting weight gainer for you because taste and flavours are subjective.

But one thing I will say is this; mass gainer flavours tend to grow on you the more you drink them.

Weight gainers are naturally thicker than protein shakes (see my mass gainer vs whey protein comparison for more differences), which I personally like, but you can always alter the creaminess and consistency by using more or less liquid, as well as mixing with milk vs water.

That said, some brands, such as Crazy Nutrition and The Protein Works, are well-known for creating delicious weight gainers that just about everyone loves.

Our #1 Recommendation
The Crazy Nutrition Mass Gainer scoop for the chocolate and vanilla flavours
Crazy Nutrition Mass Gainer

Don’t Miss Out On Discounts

When I first started this project, I just intended to try a few different weight gainers so that I could find the best mass gainer on the market to recommend to my hardgainer clients.

Little did I realise that I’d end up buying every weight gainer on the British Isles! 

Since I‘ve reviewed every UK mass gainer, I thought I might as well hunt down the best prices for my readers, because, let’s be honest, we Brits love a bargain.

I try to find the best prices in the US and other countries as well, but my main goal is to get the best deals for my UK readers, which definitely involves some haggling on my end.

So every day before and after work, I make sure that all the links on this page get you the best possible discount and the lowest UK price.

Is a Weight Gain Protein Powder The Same As a Mass Gainer?

The best weight gainers in the UK for men and skinny guys

A weight gainer protein powder can refer to both a purpose-built mass gainer supplement and a high-calorie protein powder.

However, since protein shakes rarely have more than a couple hundred calories per serving, I think that most people searching for the best protein powder to gain weight are actually looking for a mass gainer.

White protein shakes can definitely contribute to a calorie surplus (and thereby weight gain), mass gainers typically have more carbs than protein, which enables you to bulk up more easily.

What Is The Highest Calorie Mass Gainer on the UK Market?

The highest calorie mass gainer on the UK market is Mass Tech Extreme 2000 by MuscleTech, which has 2093 calories per serving and 445g of carbs.

As you can probably guess, I’m not a fan of these mega-calorie gainers. Not only are you paying a premium for maltodextrin, but you’re also making yourself extremely bloated and getting way too many calories from supplements rather than whole foods.

You can check out my Optimum Nutrition Serious Mass review if you want to see another popular high-calorie mass gainer, but honestly, 1000-calorie weight gainers usually sacrifice quality for quantity, which means worse results for you and me.

Our #1 Recommendation
Two bags of Crazy Nutrition Mass Gainer
Crazy Nutrition Mass Gainer

What Is The Best Lean Mass Gainer in the UK?

The best lean mass gainer in the UK is MaxiNutrition Cyclone because it has 204 calories, 31g of premium whey protein, 10g of quality carbs, 14g of BCAAs, 10g of glutamine, and 5g of creatine, so you’re getting a lot of nutrition for not that many calories.

Another good option is Mass Gainer from Crazy Nutrition, which has 488 calories per serving, including 55g of carbs from oats and 40g of quick-release and slow-digesting protein. And with added digestive enzymes for gastrointestinal health and enhanced nutrient absorption, it’s one of the healthiest and most effective weight gainers that you can buy.

As you can see, you don’t need a mega-calorie weight gainer to maximise your results. 

While many supplement companies compete against each other to see who can manufacture the highest calorie weight gainer, these extra calories are almost always derived from cheap maltodextrin and do nothing else other than increase their profit margins.

So don’t fall for the calorie arms race; go with a top-rated mass gainer rather than the ones with the highest calorie count—your muscles and health will thank you for it.

Where Can You Buy Mass Gainers in the UK?

The best weight gainers in the UK for building muscle

What I’ve found from testing over 65 weight gainers is that the best mass gainer deals are to be found exclusively online, and almost always direct from the manufacturer.

While it might be tempting to look on websites like eBay for cheap mass gainers, many listings are actually selling knock-off products that could end up being very dangerous for you.

This is why I always recommend buying directly from the manufacturer—so that you know you’re getting a safe and effective weight gainer supplement.

With that in mind, my #1 choice is Crazy Nutrition. Not only does their mass gainer have the highest quality ingredients, but you can also save a massive 30% every month by subscribing to this weight gainer or any of Crazy Nutrition’s other supplements.

If you’re based in the US, then Transparent Labs Mass Gainer is an excellent choice because it has premium ingredients like grass-fed whey protein and organic tapioca maltodextrin. The delivery was $14 to the UK, which isn’t that bad, but I know you can get free US shipping and a discount if you subscribe to the supplement.

A good budget pick is Bulk (formerly Bulk Powders). I like that Bulk always seems to have some kind of discount going, which means you can often stock up on mass gainer and grab a bargain.

You can also read my Myprotein Impact Weight Gainer review to see another cheap weight gainer (although I do prefer Bulk myself).

I always recommend buying directly from the manufacturer so that you can avoid the markup costs that third-party sellers put on their products.

Conclusion: What Is The Best Weight Gainer in the UK For You?

The best weight gainers in the UK for bulking up

As with any supplement, proper mass gainer usage is more important than the specific product that you buy. Yet, once you know how to use mass gainer properly, it can make sense to hunt for the best weight gainer shake on the market so that you can maximise your muscle growth.

So with that in mind, the best mass gainer in the UK in 2023 is definitely Crazy Nutrition Mass Gainer because it has the perfect amount of quality calories without any junk ingredients, fillers, or amino spiking.

With their subscribe and save option, Crazy Nutrition offers excellent value for money.

But if you’re looking for the best cheap mass gainer in the UK, then I’d go with Bulk Mass Gainer because it has a simple and effective muscle-building formula and thousands of positive reviews.

Finally, if you want to put on muscle mass but not a ton of body weight, then I recommend MaxiNutrition Cyclone because it has 3x more protein than carbs and an optimal dose of creatine, as well as glutamine and HMB.

The #1 UK Mass Gainer
Crazy Nutrition Mass Gainer
Two bags of Crazy Nutrition Mass Gainer positioned side by side
  • Contains 488 bulking calories from 100% clean sources
  • Packed with a proven 40g protein blend for quick muscle repair and growth
  • Provokes noticable weight gain with 55g of complex carbs from oats
  • Tastes amazing (to my surprise!) and mixes easily
  • Offered at the absolute lowest UK price during July
A picture of Best Mass Gainer UK founder, personal trainer Andy Williams
Andy Williams
Andy Williams is a UK-based personal trainer and bodybuilder who coaches gym-goers of all levels using proven evidence-based techniques in strength training, nutrition, and supplementation. He’s tested over 70 different mass gainers for their ingredient quality and muscle-building effectiveness and regularly shares his findings in his mass gainer reviews.
the logo for Best Mass Gainer UK showing a tub of weight gainer protein powder
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