Best Weight Gainers for Skinny Guys UK

Other than weight loss, the other reason why people exercise is to boost muscle growth or to get serious mass, especially if you’re a skinny guy who want some serious weight gain.

More often than not, optimal muscle growth requires optimal feeding strategies. While you can go out of your way and simply eat more than usual, it’s difficult to maintain that kind of lifestyle.

Not just because the food you need to eat can be pricey, but also because the menu can get repetitive. You want repetition in your training, not in the food you eat!

Thus, the need for high quality weight gainers.

There are many types of weight gainers out there and some of them are really high quality. However, knowing which ones are good can be tricky.

To help the skinny guys out there on their weight gain journey, I made a list of the 5 best weight gainers for skinny guys.

6 best weight gainers for skinny guys at a glance

If you’re in a hurry to buy a weight gainer right now, just look down and pick one (or two), and you’re set.

  1. Crazy Nutrition Mass Gainer
  2. Prep Kitchen
  3. The Protein Works Total Mass Extreme Matrix
  4. The Protein Works Vegan Mass Gainer
  5. Bulk Powders Complete Lean Mass
  6. Optimum nutrition Serious Mass

If you’re interested on why I specifically chose these five weight gainers (as well as tips on how to choose the right weight gainer for you), read on below.

Crazy Nutrition Mass Gainer

Crazy Nutrition Mass Gainer is one a high quality mass gainer supplements in the industry today. What makes it standout is its heavy use of creatine and digestive enzymes.

The digestive enzymes let the powder be absorbed fast into your system. Bypassing the “slow” digestion process lets your body take advantage of the anabolic benefits of protein and creatine sooner.

CrazyNutrition Mass Gainer

Key Features:

  • 200 grams per serving
  • Quality whey protein blend and whey protein isolate
  • Lots of creatine
  • Quality plant-based carbohydrates

How to Take:

Crazy Nutrition’s MASS GAINER is crafted to be taken on a daily basis, either before or after a workout, between meals, or even as a great meal replacement shake.

Prep Kitchen – Muscle Gain Meals

With no shopping, cooking or washing up required, it’s time to discover the joy of a dinner that’s ready when you are.

Over 30 meal recipes for muscle gain available.

Restaurant quality with macro precision, delivered chilled to your door by courier.

As used by Mitch Adams, Crossfit Champion and Eddie Hall, Worlds Strongest Man.


Prep Kitchen muscle gain meals

Key Features:

  • 100% fresh, chef-cooked healthy meal plans delivered to you nationwide
  • Take the hassle out of breakfast, lunch and dinner
  • Perfectly crafted meals to suit your health and fitness goals
  • Over 30 Fat Loss and Muscle Gain meal options
  • Choose either balanced or lower carb varieties

Muscle Gain Plan from £7.50

  • Higher calories
  • High protein
  • Balanced or lower carb option
  • 3+ portions of vegetables

The Protein Works Total Mass Extreme Matrix

Serving size often determines the quality of the ingredients included in a mass gainer.

Well, The Protein Works Total Mass Extreme Matrix definitely has the upper hand among other mass gainers with its huge 265 gram serving size.

More than just the serving size, Total Mass Extreme Matrix also has a plant-based and whey protein blend, allowing your body to have the most ideal amino acids composition with each drink.

If you take the full 265 gram serving, you are also getting 53 grams of protein and 173 grams of high quality carbs.

Total Mass Matrix Extreme

Key Features:

  • Huge 265 grams serving
  • High protein and carbs content
  • Contains medium chain triglycerides
  • Has creatine monohydrate

How to Take:

  • Recommended between 1 – 3 servings per day, depending upon your own individual needs.
  • Add 600-700ml of water or milk to your Protein Works Master Blender. Then add 5 large scoops, shake well and consume.
  • Alternatively, add 300-350ml of water or milk to your Protein Works Master Blender. Then add 1 and a half large scoops, shake well and consume.

Protein Works Vegan Mass Gainer

Being a vegan bulker is tough because your dietary choices limit your food choices as well as the supplements available for you.

Luckily, protein supplements like The Protein Works Vegan Mass Gainer exist.

Not only does the product have a high quality plant-based protein powder blend, it also makes sure you’re getting high quality carbs too.

The total protein and carbs per serving may not be as high as the rest of the mass gainer powders on this list, but it does the job of filling that vegan gap.

Vegan Mass Gainer

Key Features:

  • 100% Vegan mass gainer
  • 32 grams protein per serving
  • High quality carbs
  • Gain muscle mass with plant-based amino acids

How to Take:

It’s recommended to take 1-3 servings daily. Add 125g (2 ½ grey scoops) to 600ml of water, mix well and consume.

Optimum Nutrition Serious Mass

Optimum Nutrition serious mass gainer is one of the most tried and tested mass gainer shakes in the industry, largely due to the fact that it’s produced by the one and only Optimum Nutrition.

Optimum Nutrition’s reputation as a solid, high quality supplement company is based much on the success of their protein powder line, especially the famous ON Gold Standard 100% Whey.

What makes Optimum Nutrition serious mass gainer different is how they offer more than just a huge serving size, but also a complete set of vitamins, minerals, plus other amazing ingredients that make this mass gainer more like a pre workout.

The formula includes the likes of choline, creatine monohydrate, glutamine, and even inositol to help with blood sugar management.

Optimum Nutrition Serious Mass

Key Features:

  • 336 grams serving size
  • Premium ingredients from top to bottom
  • Can be like a pre workout
  • Contains calcium caseinate and whey concentrate for a mix of slow and fast absorption.

How to Take:

Mix 2 scoops of the powder into 24 fluid ounces (0.68 l) of cold water or milk using an electric blender. This allows you to add in fruits, peanut butter and other calorie-contributing foods.

TIP: New users should start with a 1-scoop half serving. Use post-workout and/or between meals to add calories, carbs, and protein to your healthy, balanced diet.

Bulk Powders Complete Lean Mass Gainer

When it comes to bulk powders, you can’t go wrong with what always works, and that’s what the people behind Bulk Powders Complete Lean Mass Gainer figured out.

Unlike most weight gainers, Bulk Powders Complete Lean Mass Gainer kept their formula simple and straightforward.

Instead of adding fancy ingredients, they instead went with maximising protein and carbs. It’s also made for vegetarians.

Bulk Lean Mass Gainer

Key Features:

  • Vegetarian
  • Cost-effective
  • Available in 1 kg, 2.5 kg, and 5 kg bags
  • 40 grams protein per 100 grams serving
  • Simple formula

How to Take:

Mix 3 scoops (approximately 85g) Lean Mass Gainer with 350ml water in a Bulk™ Shaker Bottle. Use 1-3 servings per day.

How Does a Mass Gainer Work?

Mass gainers work by capitalising on what is known as the anabolic process.

The anabolic process builds organs and tissues and is generally the body’s way of growing. The opposite of anabolism is catabolism, or when the body eats up tissues for sustenance.

When we do intense exercise, we tend to break down muscle tissue or use up a lot of our body’s nutrient stores.

If you don’t replenish your body’s nutrients, you might enter a catabolic state or a state where the body is getting its nutrients from existing lean muscle mass.

You don’t want that. Instead, you want the body to get its nutrients from food sources or, in the case of mass gainers, supplements.

Food vs Supplements

Let’s get this out of the way: You don’t need supplements to bulk up. You can get by with dietary proteins, carbs, and fats to get you lean muscle mass.

The problem is, the quality of food matters as well as its purity.

It goes without saying that high quality food isn’t cheap, and what we can normally afford to eat every day isn’t exactly what I’d call “pure” or without unnecessary additives.

Then, there’s also the matter of how fast the body absorbs the macro and micronutrients in food. Some foods are quickly absorbed (like eggs and milk), while others take too long (like lean meat).

That is why taking mass gainer supplements is popular in the fitness industry, especially if you’re a bodybuilder.

The advantages of supplements over food for bulking are:

  • Consistency: Ingredients indicated in mass gainers are more or less 98% accurate on a per-serving basis.
    If it says you’re getting 34 grams protein per serving, you are likely getting between 31-35 grams protein. You can’t really measure the macros and micros you get in food.
  • Quality: As mentioned, the regular food we eat doesn’t always go through quality control.
    Supplements go through quality control, or at least the reputable ones. This makes a case for supplements to be sometimes safer than regular food.
  • Speed of metabolism: Mass gainers are designed to help with lean muscle mass. This means they’re also equipped to be absorbed fast by the body.
    There’s an anabolic window where our muscles are vulnerable to exogenous nutrients, so the fastest protein blends are often preferred.
    There’s also a case for “slow absorption” proteins like calcium caseinate, but it’s frequently taken as an “overnight” or “sleep” protein powder and not the usual powders you take after a hard workout.

Mass Gainer Ingredients to Look Out For

When buying a mass gainer, it’s always smart to know exactly what you’re looking for on the get-go. However, there are just way too many brands with just as many confusing ingredients and “patents,” in their formulas.

To help you out, I made a simple list of the core ingredients to look out for when you want to try mass gainers.


When you want to take bulking seriously, you have to wrap your mind around the fact that you’re going to take a lot of carbs along the way.

Why? Because carbs are the basis of glycogen, the storage form of glucose and carbs, in humans. The body can tap into stored carbs for activities that require lots of energy, such as lifting or long bouts of cardio.

There are two kinds of carbs: Simple and Complex.

Simple carbohydrates

Simple carbohydrates are made up of just 1-2 types of sugars. These are carbs that are easy to break down. The popular examples are glucose, fructose, and sucrose, aka. refined sugar.

You generally don’t want simple carbs to dominate your carb intake when bulking. They’re quickly absorbed and can cause spikes in energy and blood sugar. They’re also easy to binge-on, which can be terrible for our health.

You will experience energy crashes, but in the long-term you can also experience fat build-up and insulin resistance, which can lead to Type 2 Diabetes.

Complex carbohydrates

Complex carbs are the carbs you want for bulking. They contain three or more types of sugars and are harder to metabolize. This allows them to have a slow-release effect when it comes to energy use.

Common sources of complex carbohydrates are cereals, vegetables, nuts, and whole foods in general. Since the sources are mostly healthy foods, going for foods high in complex carbs is the healthier choice for long-term wellness.

More than just a source of energy, carbs are also critical in the formation of this thing called adenosine triphosphate, or more commonly referred to as ATP.

What is ATP?

ATP is important when it comes to strength and gaining weight. Our muscles need ATP to flex and contract, which is really significant when we do the tough workouts designed for bulk like deadlifts, bench presses, and squats.

The more carbs are stored, the more ATP your muscles have. The more ATP, the longer you can train, plus the quality of your reps are also better.

Protein Powders

Protein is perhaps the most popular macro when it comes to bulking, and with good reason. Protein is made up of amino acids.

Without going too deep on the subject, protein is metabolised by the body into amino acids. These amino acids are used to repair and grow new muscle fibres.

That is the reason some mass gainers can go without carbs, but never without protein.

Why Protein Promotes Muscle Mass

When it comes to bulking, protein is the opposite of carbs in how you want protein to be absorbed as fast as possible. This is because you want to capitalize on your body’s anabolic state during and, more importantly, post exercise.

When we lift heavy for prolonged periods, we break down muscle fibres in the process. This is what causes DOMS or delayed onset muscle soreness.

When you have DOMS, it means the body is in a state of recovery, so you generally don’t want to do hard stuff while it does so.

What you want to do is to feed your muscles the nutrients it needs to repair the muscles fast and to make them bigger. The best way to do that is by taking protein supplements after exercising.

Among the many types of protein are whey protein and plant-based protein powder.

Whey protein

Whey protein is made from milk and a by-product of the cheese-making process. There are three main types of whey protein:

  • Whey protein concentrate
    • This is the most common form of whey protein, as it’s also the cheapest. It’s absorbed faster than regular food sources. It contains lactose, so some users may want to stay away.
  • Whey protein isolate
    • This is the upgraded version of whey protein concentrate. Many consider this as the premium version as not only does it contain up to 95% protein, the extra process “isolates” it from lactose, allowing those with lactose intolerance to take it with no issue.
  • Whey protein hydrolysate
    • The least popular whey form, and it’s not because it’s the weakest, but because it’s the most expensive. Its price is justified by the hydrolysis process whey protein undergoes. Hydrolysis pretty much “pre-digests” the whey for you, so it’s rapidly absorbed. Some say it’s absorbed up to twice as fast.

Most whey protein blends will use either pure whey protein concentrate or a combination of whey protein concentrate and whey protein isolate.

You may also see standalone whey hydrolysate, but you will likely not see hydrolysate mixed in with concentrate and isolate because of pricing.

Plant based protein

Due to the rise of vegans and plant-based “meat,” the supplement industry capitalised by adding plant-based ingredients and going as far as making entire formulations plant-based. This is how plant-based proteins came to be.

Fundamentally, there’s no real noticeable difference in bulking with whey protein or plant-based protein powder. Protein is protein, right?

The actual difference, as many have argued for years, is the “completeness” of the amino acid composition.

Whey sources are “complete” while the amino acid composition of plant-based protein varies from the plant it’s made from (typically pea starch, brown rice, plant-based soy protein, and hemp). Plant-based protein supplements address the incompleteness by mixing different plant-sources.

The discussion on plants vs whey protein is a rabbit hole I don’t want to get into right now, but the consensus is you can choose plant-based protein if you’re lactose intolerant, or if you have a vegan lifestyle, and you’d have the same gains as someone who took whey protein.

Branched Chain Amino Acids

Branched Chain Amino Acids, better known as BCAAs, are special ingredients that have the big three amino acids of bulking: Leucine, Isoleucine, and Valine. These three are the most important when it comes to muscle mass.

The difference between BCAAs and the typical protein blend is how fast the amino acids are delivered to where they need to.

Think of protein blends as a shotgun where it just supplies everything all at once. Some are used for building muscle mass, some aren’t. BCAAs are like sniper rifles, targeting muscle growth and nothing else.


The most popular pre-workout ingredient (other than caffeine).

Creatine is naturally produced by the body, but supplementation has pretty much agreed that taking exogenous creatine can be good for you. Not just lifters, but everyone else, really.

Creatine improves physical performance, boosts strength, and creates an environment where glycogen is stored easily. For bulking, creatine fuels you with ATP.

There is also hard evidence for lean muscle mass benefits when taking creatine as a post-workout.

There are even manuals written about “creatine loading,” which is often taking 20 grams creatine every day for 5-7 days followed by a maintenance dose of 2 -10 grams per day to maintain high levels. All this with the intent of optimal bulking and lifting performance.

There are many types of creatine, but it’s universally agreed that Creatine Monohydrate is the best form, if only because it’s the form with at least 200+ studies confirming its benefits for muscle growth.

Notable ingredients in mass gainers

I listed the important ingredients in a protein powder. This time, I’ll get to the auxiliary ingredients that complement them.

Fibre sources

Fibre is good for the heart and digestion. Because protein powders tend to sometimes cause gastrointestinal distress (such as constipation or irregular bowel movement), fibre helps keep everything moving properly.

After all, the last thing you want is to have a bloated feeling when you’re squatting 120 kg.

Vitamins and Minerals

Protein powders are taken either before or after exercise. Regardless, it’s critical to replenish lost vitamins and minerals on top of carbs and protein.

Vitamins and minerals are also critical in keeping your immune system up and ready. Lifters are quite vulnerable to getting sick, as they tend to exhaust their bodies to the point of making them more prone to infections.

Digestive enzymes

Much like fibre, digestive enzymes support proper digestive health.

On top of that, enzymes also help the body break down nutrients faster. This speeds up the absorption process, which can result in faster muscle recovery and better gains.


Adaptogens are herbs designed to relieve stress. Heavy lifting is naturally stressful, and you don’t want to fail a rep because you let the anxiety of training get to you.

The popular adaptogens in weight gainers are rhodiola rosea and ashwagandha.


Nootropics are ingredients designed to boost brain function or support brain health. They can also help keep your attention on lifting or focused on quality reps. Nootropics also help keep you in the zone.

FAQs about Mass Gainers


What is a mass gainer?

A mass gainer is a supplement designed to boost your body’s ability to build lean muscle mass. The formula incorporates ingredients known to facilitate the anabolic processes involved in bulking.

The supplements often come in the form of protein powders, but they can also be in the form of pre-workouts.

Do mass gainers work?

Yes, mass gainers do work. They are formulated to mimic the macros you get from regular food, but in a more efficient manner.
Instead of eating eggs, chicken breasts, and broccoli every day, you can just take a mass gainer supplement, and it can be your primary source.

However, they are not a substitute for real food, as mass gainers are regularly devoid of many essential amino acids and nutrients.

How quickly do mass gainers work?

How quickly you develop lean muscles all depends on your body, but what I can say is most of them are metabolised faster than real food sources.

This is because the ingredients are designed to be absorbed fast. If not the ingredients, they are frequently accompanied by substances that expedite the digestion process and nutrient break down, such as digestive enzymes.

What are side effects of creatine monohydrate?

The number one problem with creatine monohydrate is how it’s tough to digest. It’s one of the reasons why lifters sometimes puke mid-lift, as they tend to take a lot of creatine before working out and exercise right after.

You have to let the creatine digest for a while,, or you can end up bloating. The bloating is the reason many weight gainers now add digestive enzymes or use micronised forms of creatine.

How do I take mass gainers?

Mass gainers have different recommendations for use. See labels for more information.

Is plant protein better than whey protein?

It honestly depends on you. If you’re not lactose intolerant, or you’re okay with animal protein, whey always works as intended. If you have concerns ingesting milk or if you have a plant-based lifestyle, you’re better off with plant proteins.

Can I become fat if I take weight gainers?

Yes, there is a possibility that you can get fat instead of muscular with weight gainers, and it’s simply because of their nature.

The idea is, you take these weight gainers with the intent of working out. If you’re not going to work out, and you just want to gain weight, you’re better off just sticking to real food and avoiding weight gainers in general.

Is a weight gainer good for skinny guys?

It varies from person to person. Generally speaking, you don’t need to take weight gainers to bulk up, but weight gainers do make it easier.

What protein is best for skinny guys?

If you’re not lactose intolerant, you can go with whey concentrate or isolate if your budget permits it. If you have a plant-based lifestyle, opting for plant-based protein is a good alternative.

Are mass gainers safe?

Yes, mass gainers are safe enough considering that they’re all mostly made from natural ingredients with minimal additives. However, your body will react to different mass gainers differently.

If you feel things that aren’t supposed to happen, stop intake and seek professional help.

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