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Best Casein Protein UK Reviews

If you want the highest quality physique, you’re going to have to fuel your muscles with the highest quality ingredients.

Assuming you’ve already been lifting for a while, you probably already take a post-workout protein shake. The most common form of protein powder bodybuilders and athletes use is whey powder for its high amino acid quality and cheap price.

Casein protein powder with scoops

However, there’s another potent protein out there that can help you maximise your gains when used properly. Casein has a similar amino acid profile to whey powder but breaks down much slower. This slow-release of protein makes it the perfect option before bed or when you’re trying to maintain muscle during a cut.

Keep reading to find out how you can best use casein protein to increase your muscle growth and maximise your genetic potential. We’ll also break down some of the most common casein supplements on the market to help you find one that fits your individual needs.

Casein Protein Powder Reviews

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.

What is Casein?

Both casein and whey are proteins that derive from milk. Even though whey powder is currently the king of the protein market, casein is actually the more common type of protein in dairy products. Casein makes up more than 80% of the protein found in milk while whey only contributes 20%.

People have been separating whey and casein for thousands of years since people first begun consuming cheese. Casein protein quickly solidifies when the pH balance of milk changes whereas whey remains a liquid. The two proteins can easily be separated by adding bacteria that change the acidity of the milk and adding enzymes that speed up the solidification of casein.

If you look at the curds and liquid in a container of cottage cheese, you can easily see the difference between whey and casein. The curds are made up of casein protein while the liquid is whey.

There’s little difference between the amino acid profiles of these two types of protein. Both provide you with a full spectrum of essential amino acids. The biggest difference is how long it takes for each of these proteins to break down in your stomach.

Your body can absorb whey protein rapidly, making it a great choice for a post-workout protein, and your body breaks down casein over about seven hours. We’ll explain why you may want to take a slow-dissolving protein in the benefits section below, but essentially, it helps to prevent muscle protein breakdown when fasting.

Types of Casein Protein

You have a few different types of casein to choose from when you buy a casein protein powder. Some of the common forms include calcium caseinate, micellular casein, milk protein isolate, and casein hydrolysate.

Milk Protein Isolate

Milk protein isolate is exactly what it sounds like. It’s a concentrated form of the protein found in milk. As we already mentioned, the ratio of casein to whey protein in dairy is about 80% to 20%. You’ll find the same ratio of these two proteins found in milk protein powders.

This type of supplement provides a good balance of the benefits of whey and casein. Some of the protein is rapidly absorbed while the rest breaks down over about the next seven hours.

Calcium Caseinate Protein

Calcium caseinate is made up of about 90% protein. Unlike the next type of casein, we’ll describe, micellar casein, calcium caseinate doesn’t clot in your stomach so it breaks down quicker. It’s cheaper and considered a lower quality protein than micellar casein and is often used as an ingredient in instant creams.

You might also see sodium caseinate on some labels, which is essentially the same but bound with sodium instead of calcium.

Micellar Casein

Micellar casein is a high-quality form of casein that’s made up of roughly 90% protein. Compared to whey, calcium caseinate, and milk protein isolate, it’s very slow absorbing, which makes it the best choice if you plan on taking it before you go to bed.

Unlike calcium caseinate, it clots in your stomach and creates large bubbles of slow absorbing protein.

Hydrolysed Casein

Hydrolysed casein means that the protein molecules have been denatured (broken down) into smaller strands of protein so your body can more easily digest them. Hydrolysation is a common process for other protein sources as well including whey.

Even though hydrolysed casein is usually more expensive, you may want to stick to micellar casein. The hydrolysation process may increase the rate of absorption. However, if you’re taking casein for its slow-release benefits, you don’t want it to break down quickly.

What Are the Benefits of Casein Protein?

The number one reason why you’d take casein over other types of protein is for its unique ability to break down slowly. Casein is often called an ‘anti-catabolic’ supplement because it helps you preserve muscle mass even when you’re fasting.

People have been using warm milk as a pre-bed snack for years, and they might have been onto something. The casein found in milk products is a great choice as a pre-bed protein source to preserve muscle as you sleep.

Another great way to make the most of casein’s slow absorption is by taking it throughout the day when you’re in a cutting phase. The hardest part of any cut is making sure you’re losing fat while losing as little muscle as possible. By keeping a steady stream of amino acids floating through your blood, your body will use them to build new tissues instead of breaking down your muscles.

Casein powders are also incredibly calcium-dense. One standard-sized scoop of casein protein contains about 50% of your DV of calcium (with slight variations between brands).

When is the Best Time to Use it?

As we already mentioned, the best time to take casein protein is before you go to bed or before a period of fasting. Most brands that sell casein protein have scoops between 25-35 g. Taking 1-2 scoops (about 25-50 g of protein) before bed or before fasting should be enough to help your body prevent muscle breakdown.

The exact amount you take depends on your bodyweight and stage of training. Research shows that taking about 0.4-0.55 g/kg/meal is optimal for increasing muscle protein synthesis.

If you’re over 100 kg, you’ll likely want to take two scoops or about 50 g of protein. If you weigh 70 kg or less, you’ll probably want to take closer to one scoop. If you weigh between 70-100 kg, you’ll probably want to go with about a scoop and a half.

If you’re cutting weight, it’s a good idea to go with an amount closer to the high-end of this range since your number one priority is to maintain muscle mass while losing fat. If you’re bulking or in maintenance, you’re probably already in a positive protein balance most of the day.

As of yet, there aren’t any studies looking at benefits of taking casein protein pre-workout. However, some people think that it may help you preserve muscle tissue during extended workouts because your body will break down casein instead of your muscle tissue.

What to Look for in a Casein Protein Powder

If you plan on taking casein before bed or before a period of fasting, you want it to break down as slowly as possible. The best form of casein protein to take for slow-absorption is micellar. You may also want to avoid hydrolysed forms of casein protein since the process of hydrolysation increases the rate that your body absorbs it.

Casein generally isn’t taken as a post-workout supplement because it breaks down relatively slowly compared to other protein sources. However, if you do plan on taking it post-workout, you may want to go with a milk protein powder or calcium caseinate powder since your body absorbs these forms quicker.

A Detailed Look at the Best Casein Protein Powders

Casein protein might not be as popular as whey, but you still won’t have to look hard to find it at your local supplement store or online. However, not every brand provides you with the same quality of protein. As we’ve already looked at, the type of casein can make a big difference in how your body uses it.

Here’s a breakdown of some of the most popular brands on the UK market with the pros/cons of each to help you find the best casein protein powder for your needs.

Editor’s Choice: Bulk Micellar Casein Protein Powder

Bulk has a reputation for providing you with large container sizes for cheap prices. This casein powder doesn’t disappoint. It comes in the largest container size of any of the supplements we’ve reviewed at 4kg.

This casein supplement provides you with 25g of micellar casein per serving to supply your muscles with a steady stream of amino acids while you sleep. Even if you’re a bigger person and plan on taking two scoops a day, you can still do so at a great price.

Things We Like
  • Comes in 4 container sizes up to 4 kg
  • 25 g of protein per serving
  • Made from micellar casein
  • Four flavour options
Things we don’t like
  • Some customers report it not tasting great
  • Might be hard to mix


Bulk provides one of the best values of any casein powder we’ve seen with their 4 kg container. If you like to bulk order your proteins, you can’t go wrong with their casein powder. If you don’t feel ready to commit to a 4 kg bag, you can try a bag as small as 500 g as well.

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Bulk Bedtime Protein Shake

Complete Bedtime Protein is the second casein protein we’ve looked at by bulk. This supplement comes in containers up to 2.5 kg, which isn’t as much as their other casein option that comes in bags up to 4 kg.

If you’re looking for a very cheap micellar protein that you can take before bed to support your muscles, this supplement makes a great option. The 30g of protein per scoop helps keep your muscles fuelled with amino acids for hours. Carbs are kept low with only 1 gram per serving.

Things We Like
  • 30g of protein per serving
  • Made from micellar casein
  • Comes in containers up to 2.5kg
Things we don’t like
  • Customers often report not liking the flavour
  • Only two flavours


This casein supplement makes a good choice if you’re looking for something cheap. It only comes in two flavours and some customers report it not tasting the best, but if you put price ahead of taste, this is still a solid option.

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Optimum Nutrition Gold Standard 100% Casein

Optimum Nutrition is one of the most recognised supplement companies out there. Their Gold Standard Casein supplement is made from micellar casein. As we’ve already talked about, micellar protein is the highest quality of casein.

The micellar casein in this product will take almost an entire night to break down in your stomach, which makes it the perfect option to help you bust through a plateau or to help you through your cut.

Things We Like
  • Made from 100% micellar protein
  • Great price
  • Well-known brand with a good reputation
Things we don’t like
  • Only 23.8g of protein per scoop
  • Relatively small container size


Optimum Nutrition has once again delivered a high-quality product with their Gold Standard Casein supplement. It’s made completely from micellar casein protein, which makes it perfect as a late-night snack before bed. It also has an about market average price, which means you don’t have to break the bank to afford it.

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Grenade Hydra 6

Grenade Hydra 6 is a unique casein supplement because it’s made from 50% whey isolate and 50% micellar casein. The whey isolate in this product dissolves rapidly to provide your muscles with readily available protein while the micellar casein dissolves over many hours.

The combination of whey and casein in this product can support your muscles post-workout better than most casein supplements. Taking it after a workout will ensure that your muscles are fuelled for hours.

Things We Like
  • Large container size (1.8kg)
  • Good flavour selection
  • Contains a mix of whey isolate and micellar casein
Things we don’t like
  • Higher carb than some casein supplements
  • Lower percentage of protein per scoop than most supplements


If you’re looking for a casein supplement that you can take either post-workout or as a meal replacement, this makes a good choice because it contains a mix of whey and casein protein. However, if you’re looking for a supplement to take before bed, you might want to go with a 100% casein product.

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The Protein Works 100 Percent Micellar Casein

The Protein Works 100 Percent Micellar Casein is a pure micellar casein supplement to help support your muscles between meals. You can use this high-quality casein protein before bed or anytime during your cut to keep your body in a positive protein balance.

If you’re looking for a slow-releasing protein source to make sure your body never breaks down your muscles for energy, this might be the supplement for you.

Things We Like
  • 100% micellar protein
  • Three container size options
  • Low in sugar
  • Great flavour
Things we don’t like
  • Only 23g of protein per serving
  • Only three flavours


The Protein Works delivers a solid product with their casein supplement. They use the highest-quality micellar casein and sell it for a very affordable price. If you plan on taking casein before bed, this is a great choice.

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USN Casein Night Time Protein

USN Casein Nighttime Protein is a simple micellar casein supplement. It makes a great choice if you’re looking for something simple to take before bed to help preserve muscle while you sleep.

This casein product is very low in sugar and carbs so you can take it without worrying about spiking your insulin levels before bed.

Things We Like
  • Made from micellar casein
  • Low in sugar and carbs
  • Not many filler ingredients
Things we don’t like
  • Relatively small container size
  • Some customers report it being hard to mix


USN’s casein supplement is a great option if you’re looking for something simple to take before bed. It provides you with a solid 24g of micellar casein per serving to help prevent protein breakdown while you’re sleeping and contains few filler ingredients.

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PINK SUN Organic Micellar Casein Protein Powder

Pink Sun Organix Micellar Casein is a micellar casein supplement that comes from organic milk. It’s unflavoured, so if you’re somebody who likes to avoid artificial sweeteners, you may prefer this supplement over some of the alternatives on the market.

This pure micellar casein supplement can help you support your muscles while fasting without the filler ingredients that many supplements include.

Things We Like
  • Made from micellar protein
  • No added sugar
  • From organic milk
Things we don’t like
  • Small container size
  • Small scoop size (15g)
  • No flavoured options


Pink Sun’s casein supplement is a great choice for anybody who puts an emphasis on eating organic. It only comes unflavoured. If you like to avoid artificial sweeteners, you’ll love this supplement. If you want something a little tastier, you might want to go with one of the other options we’ve listed.

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Ekopura Organic Casein Protein from Grass-Fed Cows

Ekopura Organic casein protein is an all-natural casein supplement. It’s sourced from grass-fed cows and is completely additive-free. A lot of supplements contain filler ingredients to improve the taste. However, if you prefer something without additives, this might be the supplement for you.

The all-natural formula of this micellar casein supplement can provide your muscle cells with a steady-stream of organic protein to fuel your muscles as you sleep.

Things We Like
  • Made from micellar protein
  • No additives
  • Sourced from grass-fed cows
Things we don’t like
  • Only 19.50g of protein per serving
  • Small container size
  • More expensive than most brands


If you don’t mind paying a little extra for an organic and all-natural product, this might be the casein supplement for you. Even though it’s all-natural, it’s still made from micellar casein protein for slow-absorption.

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MuscleTech NitroTech Casein Gold

MuscleTech’s NitroTech Casein Gold is a casein protein supplement that’s ideal for anybody looking for a slow-absorbing protein supplement. Each scoop provides you with a solid 24 g of protein to make sure your body stays in an anabolic state even as you sleep.

This product is made from a blend of milk protein isolate, calcium caseinate, and micellar casein. Taking it in the evening will allow you to recover from your hard workouts even as you sleep.

Things We Like
  • Very little sugar and carbs
  • Good value per scoop
  • Mixes well
  • Contains micellar casein
Things we don’t like
  • Mediocre flavour
  • Contains a blend of different caseins


Overall, this casein supplement offers good value per scoop. It contains a mixture of different types of casein, and it’s not clear how much of each type of casein it contains. However, if you’re looking for a budget option, MuscleTech’s product is a solid choice.

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Whey protein and casein protein can both be valuable tools to maximise your body’s protein synthesis. Because whey protein is digested much quicker, it makes a better choice for a post-workout shake since you want to quickly get more protein into your muscle cells. Casein protein is a slow digesting protein, which makes it a better choice before you go to bed.

If you’re looking for a casein product to take in the evenings, we feel it’s hard to go wrong with Optimum Nutrition’s Gold Standard. It’s made from 100% micellar casein and provides you with a high-quality product at an affordable price.

Grenade Hydra 6 offers a unique blend of 50% whey protein isolate and 50% micellar casein. It makes a great choice as a post-work protein if you’re in a calorie deficient. Not only will the whey powder give you an immediate protein boost, but the casein will continue providing your muscles with protein for hours.

If you like to bulk order your protein supplements, you might like Bulk Micellar Casein Protein Powder. You can buy it in bags up to 4 kg and provides the best value of any of the casein protein powders that we’ve looked at.

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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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