Casein protein
Casein protein


Casein protein is a protein found in milk that gives milk its white color. Cow's milk consists of around 80% casein protein. In addition to milk, casein protein is found in yogurt, cheese, and infant formulas, as well as in a variety of dietary supplements. Do not confuse casein protein with casein peptides. Casein peptides are made by breaking casein protein down into smaller pieces.

Casein protein is taken by mouth to improve athletic performance, diabetes, liver disease due to alcohol consumption, and many other conditions, but there is no good evidence to support these uses.
When taken by mouth: Casein protein is LIKELY SAFE for most people when taken by mouth. Most adults do not experience side effects when casein protein is taken for as long as 12 months.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if casein protein is safe to use in amounts greater than those found in foods when pregnant or breast-feeding. Stay on the safe side and stick to food amounts.

Infants and children: Casein protein is POSSIBLY SAFE for children and infants when taken by mouth. Most infants receiving casein protein formulas do not experience side effects.

Milk allergy: People with milk allergy can be allergic to the proteins contained in milk such as casein protein. If you have a milk allergy, it's best to avoid taking casein protein.


NatMed Pro rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
  • Infant development. Most research shows that feeding premature, low-birth weight, and healthy infants a formula containing casein protein does not increase or decrease growth compared to breast milk, whey protein-based formula, rice hydrolysate formula, cow's milk formula, or amino acid-based formula.
Insufficient evidence Effectiveness definitions
  • Liver disease in people who drink alcohol. Early research shows that administering a casein protein supplement through a feeding tube for 28 days improves mental status in patients who have liver disease from alcohol consumption. Other early research shows that taking a casein-based formula daily for one year lowers the risk for hospitalization and infection in these patients. But casein protein does not seem to reduce the risk of death.
  • Athletic performance. Some early research shows that taking casein protein before or after exercise improves strength and athletic performance. But not all research agrees. Some research also shows that casein protein works just as well as whey protein or creatine for improving athletic performance. But other research shows that whey protein is better than casein protein.
  • Cirrhosis. Early research shows that drinking a casein protein supplement for 4-6 days improves mental status in people with cirrhosis.
  • A lung disease that makes it harder to breathe (chronic obstructive pulmonary disease or COPD). People with chronic obstructive pulmonary disease (COPD) often lose muscle function over time. Some studies show that taking casein protein along with exercise builds muscle. But early research shows that taking casein protein daily for 8 weeks does not improve lung or muscle function in people with COPD.
  • Diabetes. Limited research suggests that taking casein protein with food might increase insulin, but not blood sugar levels, in people with diabetes.
  • Diarrhea. Early research in infants with the stomach flu shows that using a formula containing casein protein, instead of cow's milk, reduces diarrhea.
  • Muscle soreness after exercise. Early research in strength training athletes shows that taking a specific protein supplement containing casein protein and other ingredients before and after exercise does not reduce muscle soreness.
  • Persistent heartburn. Early research in children with brain damage shows that a formula containing casein protein doesn't work as well as whey protein formula for reducing symptoms of heartburn. But casein protein and whey protein seem to have similar effects in infants with heartburn.
  • Reduced brain function in people with advanced liver disease (hepatic encephalopathy). Early research shows that taking casein protein for 3 months does not improve mental function in people with chronic liver disease.
  • Swelling (inflammation) of the liver caused by the hepatitis C virus (hepatitis C). Early research shows that taking casein protein daily for 12 weeks improves quality of life in people with hepatitis C infection.
  • High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Most research shows that casein protein does not improve "good" or "bad" cholesterol levels in people with normal cholesterol or in people with high cholesterol. But some small studies show that it might improve these levels in some people. Also, eating casein protein seems to lower the levels of a certain type of cholesterol called lipoprotein(a).
  • High blood pressure. The effect of casein protein on blood pressure is unclear. Some research shows that it can reduce systolic blood pressure (the top number), while other research shows that it can reduce diastolic blood pressure (the bottom number).
  • Obesity. Most research shows that taking casein protein does not reduce body weight or appetite in people who are overweight or obese. But some early research shows that having a liquid snack containing casein protein reduces hunger in overweight patients. Also, early research shows that taking casein protein for 12 weeks prevents weight gain in obese people who have already lost weight. In overweight children, early research shows that drinking a milk drink containing casein protein daily for 12 weeks instead of water increases body weight.
  • Other conditions.
More evidence is needed to rate the effectiveness of casein protein for these uses.

Dosing & administration

The appropriate dose of casein protein depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for casein protein. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Interactions with pharmaceuticals

It is not known if Casein Protein interacts with any medicines. Before taking Casein Protein, talk with your healthcare professional if you take any medications.

Interactions with herbs & supplements

Green tea: Green tea contains catechins, which are natural chemicals believed to explain some of green tea's beneficial properties. Taking casein protein with green tea might increase the absorption of some catechins and decrease the absorption of others.
Iron: Casein protein might decrease iron absorption. However, hydrolyzed casein protein does not seem to interact with iron.
Zinc: Casein protein might decrease zinc absorption. However, research on this interaction is inconsistent.

Interactions with foods

There are no known interactions with foods.


Casein protein provides the body with all of the amino acids necessary to help build muscle. Casein protein is digested more slowly than other proteins, so it might be better at reducing appetite and increasing feelings of fullness. has licensed monographs from TRC Healthcare.
This monograph was last reviewed on 30/03/2023 11:00:00 and last updated on 07/11/2020 03:24:18. Monographs are reviewed and/or updated multiple times per month and at least once per year.
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