What is Casein? Benefits, Harm. How to Take It


Experienced bodybuilders and professional athletes are knowledgeable about casein and are well versed in when and how to take it to get the most out of your body without harm.

We want to devote this piece to fitness beginners who are just discovering the vast world of sports supplements – assistants allowed by the international doping committee in achieving their goals, objectives, and results.

What is Casein?

Translated from Latin, caseus means cheese, but we use the English pronunciation. It is a protein that, along with albumin and other types of animal proteins, is the main component of milk, where it is combined with calcium (calcium caseinate) and performs a storage function. The precipitation of casein, in which milk coagulates, occurs due to the action of enzymes of lactic acid bacteria, rennet, acids. It is absorbed extremely slowly, and for this, it needs the presence of a sufficient amount of pepsin in gastric juice.

This complex protein containing a phosphate group, which is often called caseinogen by specialists, is produced in the mammary glands of female mammals from free essential amino acids found in the blood. Caseins differ from each other by the combination, quantitative and qualitative content of polypeptide chains of amino acids – fractions α, β and γ, and each of them also has varieties. Casein breaks down when heated to 130 ℃.

Where Casein is Contained?

casein protein

Casein is found only in milk and dairy products. Let’s list in what % ratio of the total mass and in which products casein is contained:

  • 1.9–2.3% – sheep, mare, donkey milk;
  • 2.8–3.5% – goat and cow milk;
  • 13-15% – cottage cheese, soft and unripe cheeses;
  • 18% – hard, aged cheeses.

Separately, we will clarify that the % of the specific gravity of casein in fermented milk products coincides with the % of milk from which they are made. For example, in kefir made from cow’s milk 2.5% fat, the casein content will be 3%.

There are 2 types of casein – technical and food. The first to be isolated was technical casein. In 1892, casein glue began to be produced in Switzerland and Germany. Today, technical types of casein are also used in other building materials and paints, in the production of cardboard and coated paper, during the hardening of natural leather, to stabilize rubber, in the manufacture of artificial wool and silk. This animal protein can also be found in cosmetics and hair care products, soaps, and dishwashing detergents.

Dietary casein can be found in foods such as:

  • Infant formula;
  • Modified dairy products;
  • Bakery products;
  • Dry breakfasts;
  • Marshmallow, candies like toffee, caramel, nougat;
  • Carbonated sweet drinks, drinking chocolate;
  • Sauces;
  • Liqueurs.

Today, food-grade casein is the basis for experimental imitations of chicken, beef, bacon and ham, and even fish.

Separately, we note that casein is part of the dishes of the space diet.

In recent years, this supplement has become especially popular among athletes and is also included by doctors in various types of diets for adults and children, both for weight loss and weight gain. Casein-based diets for children with autism are also being promoted.

Manufacturing Technology

casein vs whey

Modern technologies for the production of food casein make it possible to obtain high-quality pure milk protein. In addition, 2 new production methods have appeared.


The first method allows the production of micellar casein. With the help of the technology of gentle microfiltration, as well as without the participation of acid and high temperatures in the process, it is possible to isolate caseinogen with an undisturbed molecular structure, qualitatively purified from lactose, carbohydrates, fats, and other impurities. Unlike ordinary casein protein, micellar casein lasts not 6–8, but 12 hours, dissolves well in water, and does not create a sticky consistency in the drink.


The second method allows you to obtain hydrolyzed casein. which also does not contain any foreign impurities. It is absorbed quickly and easily since in the process of hydrolysis with water and special enzymes, protein molecules are split into separate short-chain amino acid bonds. Alas, this innovative technology is still too expensive. Therefore, casein hydrolyzate is still added in small amounts to protein complexes, since it is too expensive by itself.

Benefits of Casein

Let’s list its beneficial properties:

  • Protection of muscles from destruction, by long-term saturation of muscle cells with amino acids, with long breaks or restriction in food;
  • Suppression of appetite;
  • Accelerated growth of skeletal muscle cells;
  • A source of calcium and phosphorus.

Also note that, unlike whey concentrates, where there is inevitably a lot of lactose, as well as from egg proteins, casein intolerances and allergies are rare.

Is There Any Harm from Taking Casein


Disputes about the dangers of it are based on the fact that when it is broken down in the stomach, casomorphin is formed – a short-chain peptide that has opioid properties and, most importantly, behaves as a histamine releaser. This means that the production of histamines is triggered in the body, which contributes to the occurrence of allergies or the intensification of the manifestations of already existing allergic reactions. At the same time, it is especially emphasized that casomorphin dipeptides can be inactive for a long time in the intestine and in the cells of the endocrine glands.

In addition, there are authoritative studies that confirm the connection of large doses of some of the β-casomorphins obtained as a result of the digestion of some of the β-caseins in cow’s milk, with the causes of the development of atherosclerosis, hypertension, type 2 diabetes mellitus. Hypotheses are considered that a lack of casein may be a risk factor for autism and schizophrenia.

However, if you follow the dosages indicated in the instructions, and adhere to the movement regimen recommended by a fitness trainer or attending physician, it is impossible to harm your health.

Contraindications to Use and Side Effects

Naturally, casein-containing foods and sports supplements are not necessary for those who have an individual intolerance. Its symptoms after taking a drug with casein are redness of the face and décolleté, difficulty breathing, hives, nausea, abdominal pain, constipation. They can manifest themselves both separately and in different combinations or all together.

Contraindications to casein intake are as follows:

  • Pregnancy;
  • Lactation period;
  • Age under 18 and after 70 years;
  • Chronic stomach diseases.

If you have liver and kidney problems, the dosage of casein intake is adjusted by your doctor.

This supplement can cause side effects. Possible – nausea, urge to vomit, abdominal pain, flatulence, diarrhea, or constipation. If you experience these symptoms, stop taking it for a few days and then start again with lower doses.

How to Take Casein

How much and what kind of supplements with casein protein for non-athletes should be told by the attending physician. They will take into account the purpose of the intake, age, weight and height, physique and metabolic characteristics, the presence of diseases, the prescribed diet, and physical activity. But there is also a general recommendation for everyone – you need to take casein before going to bed.

Features of Use for Athletes

casein sensitivity

In sports practice, as well as in bodybuilding, it is widely used due to the following beneficial effects:

  • Promoting muscle growth when gaining or losing weight;
  • Suppression of appetite;
  • Promoting the burning of subcutaneous fat reserves;
  • Normalization of the work of the small and large intestines, their microflora, and hence the strengthening of general immunity.
  • Another argument in favor of using this kind of protein is the highest quality of phosphoprotein, which favorably distinguishes it from other proteins of both animal and plant origin.

How is casein taken by athletes? It depends on the goal pursued and the type of drug:

  1. To increase muscle mass or while cutting, slowly absorbing forms are taken once at night – either casein protein or micellar casein. Protein at night provides your muscles with amino acids and enables them not only to recover but also to increase strength and volume.
  2. It is taken in the morning or just before a long period of abstinence from food. It suppresses appetite and improves the “well-being” of the intestinal microbiota, even in the absence of food.

The recommended standard dose of casein protein or micellar casein for gaining muscle mass is 30 g, and during the cutting period, or when losing weight – 15 g.

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