What’s Casein protein? Health Benefits, and How to Use?

10 minutes read. 


Mammalian milk is a complex fluid mixture of various proteins, minerals, and lipids (fat and oil) which play an important role in providing nutrition and immunity to the newborn as well as an adult. (1)

Casein proteins, form about 80% of the bovine (cattle) milk proteins and form large colloidal particles with calcium phosphate to form casein micelles.

One of casein protein’s greatest advantages is the time it takes to absorb in the body and how long it lingers in the body. Both factors make it beneficial for building muscle fast and preserving the body’s lean muscle tissue.

One of the vital benefits of casein protein is that it hits your bloodstream very quickly and stays where they need to be in order to help build muscle tissue for many hours.

So if you want to build your lean muscle tissue fast you may consider starting to take casein protein, but you need to be aware of what you can benefit from casein protein before purchasing one, that’s why I bring you this article.

Feel free to skip ahead.

What’s Casein protein?

The word “Casein” probably came from French caséine, from Latin Casesus meaning “cheese” _ or “to ferment or to become sour”. (2)

Casein protein is made from milk, just like whey protein, that’s why it’s sometimes called “milk protein” since around 80 percent of the protein found in cow’s milk is casein. (1)

Casein protein is actually a naturally abundant source of branched-chain amino acids. Casein is the curd you see in milk.

What’s curd?

Curd is a soft, white substance formed when (cattle) milk coagulates, used as the basis for cheese. (3)

It also makes up 20 percent to 40 percent of human breast milk. It’s also abundant in raw sheep milk (cheese), a pure source of casein.

Casein protein, like whey protein and other high-protein foods, is made up of various “building blocks” called essential amino acids and non-essential amino acids.

As your body can naturally make non-essential amino acids, but it can’t make essential amino acids that’s it’s crucial you supply your body with these essential amino acids through animal protein.

Case protein is like other animal proteins that provide you with abundant essential amino acids that the body needs for vital biological function.


There’re three types of casein protein you can find in the market. They include:

1. Calcium caseinate

It is the protein extracted from the insoluble portion of milk and purified in a chemical process. It is considered to be the lowest quality form of casein and is commonly sold as a food ingredient.

It is soluble and does not clot in the stomach. It is believed to neutralize capsaicin, the active and hot ingredient of peppers, jalapenos, habaneros, and other chili peppers.

2. Micellar casein

It is the purest form of casein protein available on the market. It exists in its natural form and is more readily digested and assimilated by the body. (4, 5)

Micellar casein is labeled as an anabolic, slow-release protein because it gels in the small intestine and is released gradually to the muscles over a six or seven-hour span.

Interestingly enough, some health experts consider this type of casein to be a general-purpose supplement ideal for daytime use. This is because it allows for greater nitrogen retention for long stretches.

Because of this facet, it promotes ongoing protein synthesis through the continuous release of the key muscle-building amino acids leucine, arginine, and glutamine.

Ideal consumption would be every six to seven hours throughout the day and prior to bed. Fitness experts do not recommend taking it immediately after a workout. Instead, a fast-acting hydrolyzed whey protein isolate supplement would better fit the bill.

3. Milk protein-milk protein isolate

Is a type of casein that has both micellar casein and whey protein.  In this type, casein concentration is roughly 80 percent whilst whey is 20 percent. This makes it an economical choice for post-workout purposes.

Milk protein isolates are extracted from cow’s milk by way of a filtration process that separates the protein from the milk. It has a high amino acid composition which makes it an ideal ingredient for protein bars and meal replacement powders.

Additionally, this form of casein is easily digestible. The American Dietetic Association recommends this supplement to individuals with weak digestive systems or who have trouble processing certain foods.

Casein protein also exists in four subtypes which include:

1. Alpha s1-casein,

2. Alpha s2-casein,

3 Beta-casein, and

4.κ-casein. (5)

Alpha-Casein protein is a mixture of Alpha s1- casein and Alpha s2-casein protein, which is the main fraction of milk protein. How well casein protein dissolves depends on the casein type.

Let’s find out the exact nutrients you get from a single serving of casein protein.

Nutrition Facts

Depending on the brand of casein protein powder you buy, the calories and protein amounts can vary. To get the most benefits, look for a brand that’s low in sugar or sweetened naturally with organic stevia extract and natural sweeteners like cocoa powder or vanilla extract.

For example; Gessntl casein protein powder. (6)

Brand: Gessntl contains the following nutritional values:

Serving size2/3 cups (52g)
Calories     190 kcal 
 Percentage Daily Value (% DV)
Total fat: 1 g      1
Saturated fat: 1 g                             Saturated fat: 1 g                                   0
Tran’s fat: 0 mg                     0
Cholesterol: 19.8 mg             7
Sodium: 350 mg                    15
Total carbohydrate: 5 g        2
Dietary fiber:       1 g    4
Total sugars:       1 g    2
Protein:      40 g           80
Vitamin C: 0 mg                    0
Vitamin D: 0 gm                   0
Iron: 1.4 mg                          8
Calcium:    699.9mg              54
Phosphorus:  0 gm                0

In general, a serving of casein powder has around:

  • 120 calories (total energy)
  • 23 grams protein
  • 1 gram fat
  • 1 gram sugar
  • 450 milligrams calcium (45 percent DV)

What’s Casein protein made of?

Casein protein is precipitated from skim milk by acidifying it to produce acid casein, or the milk is treated with rennet to produce rennet casein.

The precipitated casein curd is separated from the whey, washed, and dried. The water-soluble derivatives of acid caseins, produced by reaction with alkalis, are called caseinates. (7)

Caseinate (plural caseinates) is any of several salts derived from casein via the coagulation of milk protein.

Is casein protein better than whey protein? What’s the difference?

Whey protein and casein protein differ in terms of their bioavailability and effects on muscle synthesis.

Casein is known as the slow-digesting component of milk protein. Although whey protein possess similar characteristics,

It’s believed to cause more of a fast “amino acid spike” in the bloodstream compared to casein. (8)

Just like casein protein, whey protein is a fast source of protein so it provides amino acids t your body quickly after taking it, however, it wouldn’t last in the body when compared with casein protein.

Casein protein has a lower percentage of branched-chain amino acids compared to whey protein, which is one reason it’s slower to digest and also tends to work for longer.

Because of its absorption and timing, research suggests that casein increases protein production in the body a bit less than whey protein.

Casein has also been shown to slow intestinal motility (damage).

Whey protein has more sulfur than casein, which can also change the way the body uses it.

The main point you should pick here is that both casein and whey protein can supplement your lean muscle well and include all the essential amino acids you need, but whey protein has more branched-chain amino acids and, therefore, might be slightly better at facilitating muscle protein synthesis (production).

But one study carried out on body composition and performance in female athletes using both casein and whey protein found both proteins provided similar benefits to the individuals who participated. (9)

Feel like skipping? Let’s move down a bit to find out what exactly your body benefits from consuming casein protein.

 Health Benefits

What are the health benefits of casein protein?

  1. Helps Build Muscle Mass and prevent Muscle-Wasting

Bodybuilders and athletes have used this supplement for decades.

Like other animal proteins, it contains all the essential amino acids that your own body is unable to produce naturally. Most importantly, it provides a high amount of leucine, which initiates muscle protein synthesis. (10, 11, 12, 13)

If you only consume a low or moderate amount of protein, it may help you boost muscle growth simply by increasing your protein intake. (14)

One study compared those who took casein to two other groups. Once consumed whey protein and the other had no protein. (15)

The researchers found that the casein group experienced double the muscle growth and triple the fat loss compared to the placebo group. The casein group also experienced more fat loss than the whey group.

It may also enhance long-term muscle mass by reducing protein breakdown. This process occurs on a daily basis when your body is low on energy and amino acids. It’s accelerated during exercise or weight loss. (16, 17, 18)

For this reason, casein is often used at night to prevent the protein breakdown that may occur, since you go through a relatively long period without food while you sleep.

In one study, a casein protein shake before bedtime helped strength-training men increase type 2 muscle fiber size by 8.4 cm2 in the supplement group, compared to 4.8 cm2 in the training-only group. (19)

They also found the casein group increased strength to a greater extent or about 20% more than the training-only group.

2. Lasts Longer than Other Protein Sources

Although it’s absorbed quickly, casein is still considered a relatively “slow-digesting” protein because of the length of time its amino acids stay within the bloodstream.

Just like slower-releasing carbohydrates are beneficial as opposed to fast-acting types that can spike blood sugar rapidly, protein foods can sometimes work the same way.

The body can slowly digest casein protein, which means muscle tissues have a longer opportunity to use the amino acids for repair work and growth.

As you’ll learn below, the timing of casein definitely has its advantages, but depending on your goals for building muscle, there may be certain times you want to skip it and use a faster-acting protein instead.

3. Reduction of Triglyceride levels.

One study in 10 overweight individuals found that it reduced triglyceride levels after a meal by 22%. (20)

4. Reduce free radicals forming in the body.

 Some of the peptides in casein protein powder may have antioxidant effects and fight the buildup of harmful free radicals (21, 22 23)

5. Promote Fat loss

12-week training study found the average fat loss among people taking the supplement was three times greater than in a placebo group. (15)

 I hope you getting value.

6. Reduce Your Appetite and Help with Weight Loss

Even if you only exercise in a moderate way and aren’t looking to put on muscle mass, protein supplements can still be beneficial when it comes to curbing hunger and cravings.

Many people choose to use protein powders for their convenience coupled with the fact that they can suppress appetite to a certain extent.

Have you noticed that whenever you eat only sugar-heavy carbohydrates without adding any protein, you will likely get hungry faster and want to eat another food? Unlike when you eat more protein and fewer carbohydrates, you will fill full and may not feel hungry for many hours of the day

However, the effects differ depending on the person but some people do really well using protein powders along with other nutrient-packed ingredients in smoothies as an easy breakfast, a high-protein snack, or even as a meal replacement.

Protein is very satisfying and can help you go from one meal to the next without hunger pangs and sugar cravings

Researchers compared the hunger-reducing effects of hydrolyzed casein protein, intact casein, and intact whey protein in 24 overweight adult men and women.

They determine the effects of these different protein supplements on overall energy expenditure (EE) and appetite regulation, essentially the number of calories in versus calories out. (24)

The two types of casein and the one type of whey protein all had similar effects over the course of 24 hours on energy expenditure (calories) and appetite, although some results suggested whey protein seemed to work somewhat better when it came to positively affecting the individual resting metabolic rates

You should understand that protein requirements increase the more active you become, and they’re especially high when you regularly lift weights or do other types of lengthy training.

  • Antibacterial and immune boost.

Cell studies suggest it may provide antibacterial and immune benefits and reduce high blood pressure. (24, 25)

 A1 casein vs A2 casein protein controversy

What’s the difference between A1 casein and A2 casein protein?

casein (white), whey (brawn)

Different types of cows produce slightly different casein proteins.

One of the proteins in casein (called beta-casein) exists in several forms. Most cow’s milk contains a mixture of A1 and A2 beta-casein, whereas the milk of certain breeds contains only A2 beta-casein.

Some observational research has started to link A1 beta-casein to health issues such as type 2 diabetes and heart disease. (26, 27, 28)

However, observational research is far from conclusive and only highlights associations, which tend to be unreliable in nutrition. Other studies on A1 beta-casein find no detrimental effects. (30, 31)

The research and debate on A1 and A2 beta-casein continue, but for now, this is probably not something you need to worry about.

How to use casein protein

Casein protein mostly come in a powder form, you can take the powder form or better prefer to take it in whole food form by taking whole cattle milk.

How much casein protein can you take per time/day?

Most people who supplement with casein protein are taking it before bed. For example, you can eat 1-2 scoops (25-50 grams) of casein protein powder mixed with water. You can simply put casein and water in a shaker bottle and mix it that way, or in a blender with some ice.


However, protein needs vary from person to person depending on many factors, but some general guidelines for using casein protein are as follows:

  • About 0.681 grams of protein per pound of body weight if you’re an athlete or a highly active person
  • About 0.45 to 0.68 grams per pound of body weight if you’re looking to lose weight and tone up
  • About 0.36 grams per pound of body weight to generally maintain your health and weight. (32)

When is the best time to take casein protein?


Casein protein is best taken before bedtime to preserve hard-earned muscle mass because the supplement has the ability to feed the body over a long period of time, (up to seven hours).

A woman who weighs 140 pounds who’s active and wants to improve her diet might aim to eat up to 63 to 95 grams of casein protein a day.

Side Effects

Does casein have any harmful side effects?

The myth that high protein intake causes ill health has been debunked many times.


Direct studies and reviews have highlighted that there are no negative effects in healthy individuals taking casein protein.

The only exception is those with current kidney or liver disease, who may need to limit their protein intake.

If you take 1-2 scoops of casein per day, then it is highly unlikely that you will get any noticeable side effects, let alone serious ones.

That being said, some people are allergic to casein or intolerant to lactose, which is often found in small amounts with the supplement.

Other people may become bloated or experience other digestive symptoms, but this depends on the individual.

Like whey, casein protein is very safe for human consumption. As discussed above, it may even have some impressive long-term benefits for your health.

The question you have in mind.

Casein protein powder or casein protein in whole food form, which one is better?


Since casein protein is made from skim milk, consuming skim milk will provide your body with pure and unadulterated casein protein. However, both choices will likely provide the same essential amino acids to your body.


Casein is a slow-digesting protein that can boost muscle growth and aid recovery after exercise. Taking it can improve your health, as well as increase your total daily protein intake. This is an important factor in weight loss and muscle growth.

The major health benefits of casein protein include:

  • Repairing broken-down muscle fibers after a workout while you sleep
  • Restoring nitrogen balance during muscle recovery
  • Gives you maximum satiety thereby reducing your intake of carbohydrates.
  • Reduce fat gain and improve weight loss.
  • Regulating blood sugar levels

Casein protein is best taken before bedtime because it helps repair muscle waste and can last up to 7 hours in the body. You can eat one to two scoops mixed with water or blend them with some ice.

So far, there’s no harmful side effect recorded in a healthy person consuming casein protein except for those who have health issues like kidney disease.

 Also, A1 and A2 casein proteins are also safe for consumption, although scientists are having controversy over this. But there’s nothing to worry about for now.

I hope you get the value worth your time. I appreciate the time you spend with me. Leave a comment if you like this post.

Do you have any questions regarding casein protein I didn’t answer here? Have you eaten casein protein before, What was the experience like? Please feel free to share your story with me in the comment below.


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