Casein protein is the main protein found in cow’s milk, and is what gives milk its white color. Casein is a complete source of protein, meaning it contains all nine essential amino acids the body can’t produce on it’s own.
Typically, casein protein is sold as protein powder and may be used by weight lifters, athletes, or people looking to increase their protein intake.
Consuming this protein source may offer several benefits, like helping you build muscle and recover from workouts. It’s also especially high in calcium, which can help support bone health.
Amino acids are the building blocks of protein. In the body, amino acids and protein perform many functions, including helping the body grow, repairing tissue, and providing a source of energy. Amino acids are also important for creating other compounds, like hormones and neurotransmitters.
There are 20 types of amino acids, nine of which our bodies can’t produce on their own. Those nine are called essential amino acids, and we must get them from food or supplements.
Some sources of protein only contain a few amino acids, while others contain all nine. The ones that contain all nine essential amino acids are called complete proteins. Most animal sources of protein, including casein, are complete sources of protein. Some plant sources of protein are complete proteins, like soy, but most are not.
Consuming casein protein can help improve muscle growth and recovery, especially when combined with resistance training.
Regularly doing muscle-strengthening exercises and consuming enough protein is important for muscle growth. The American Heart Association recommends adults engage in muscle-strengthening activities at least twice per week.
This kind of exercise causes small tears in your muscle fibers that dietary protein helps repair, which helps your muscles grow. Keeping your muscles strong helps support your joints and promote good balance to prevent injuries.
One study found consuming at least 40 grams (g) of casein protein 30 minutes before sleep and after an evening resistance workout helped facilitate muscle recovery and growth. The researchers also noted casein protein may reduce muscle damage and the inflammatory response to exercise, which can reduce muscle soreness.
Casein protein is an excellent source of calcium, which is important for bone health. A 30-gram serving of protein powder consisting of mainly casein powder provides about 45% of the Daily Value (DV) of calcium, although this may vary across products. In contrast, it would take about 86 g of whey protein isolate to get that much calcium.
Consuming convenient, dense sources of calcium may be especially beneficial for certain groups. For example, postmenopausal women have higher calcium needs to prevent decreases in bone mineral density due to estrogen loss. People with lactose intolerance are also more likely to struggle to meet their calcium needs.
Our team of registered dietitians thoroughly research and review supplements, evaluating products on several criteria, including safety, efficacy, dosage, quality of ingredients, and testing certifications. We also test protein powders in our lab to make sure they’re actually pleasant to consume. You can find all of our recommendations in our complete guide to protein powders here, but this is our top choice for casein protein powder.
Dymatize Elite Casein Vanilla Protein Powder
This Informed-Choice Certified casein powder provides 25 grams of protein per serving, and 45% of your daily calcium needs. It has a smooth texture and great taste, even when mixed with just plain water. It contains sugar substitues, so it is slightly sweet, but with no added sugar.
Casein protein is typically sold as a protein powder and the specific nutrition facts may vary slightly based on the brand and whether or not it is flavored.
One third cup (30 g) of an unflavored casein protein powder containing only instantized micellar casein includes the following nutrition information:
- Calories: 110
- Fat: 0 g
- Sodium: 25 milligrams (mg)
- Carbohydrates: 0 g
- Fiber: 0 g
- Added sugars: 0 g
- Protein: 24 g
- Calcium: 579 mg (45% of the DV)
Casein protein is a good source of calcium, which is important for bone health. Many Americans don’t get enough calcium through regular diet, so consuming a protein powder containing calcium like casein may help you meet your needs.
Flavored casein protein powders may contain added sugars or non-nutritive sweeteners like Stevia or sucralose. While these non-sugar sweeteners are generally recognized as safe, they can cause digestive upset for some people.
If you have a milk allergy, it’s important to avoid casein protein since it is a milk protein. Milk allergies are most common in children, who typically don’t need to consume protein powder. Some casein protein powders may also be processed in facilities with common allergens like soy or nuts, so be sure to read the supplement facts label if you have any food allergies.
For anyone, consuming too much casein protein powder could be harmful. Although rare, consuming too much calcium could lead to excess calcium in the blood, or hypercalcemia, which can cause increased cardiovascular risk, among other symptoms.
Eating too much protein may also cause you to have an imbalanced diet lacking in carbohydrates, fat, fiber, and other nutrients. Consuming food sources of protein rather than supplemental powders is also important because many protein-rich foods offer other nutrients, like vitamin B12 and iron in meat or fiber in beans.
People with chronic kidney disease may also need to limit their protein intake to preserve kidney function.
Whey protein and plant-based protein powders are common alternatives to casein protein. Whey protein is another complete source of protein derived from milk, but some forms of it aren’t suitable for lactose intolerance, particularly whey protein concentrate.
Plant-based protein sources used in vegan protein powders aren’t always complete protein sources on their own. Soy and pea protein are two examples of complete sources of plant protein. Soy protein has been shown to be effective at promoting muscle protein synthesis—the process that maintains and builds muscle—when consumed throughout the day, particularly around workouts.
Casein protein powder can be added to baked goods, oatmeal, or smoothies, or it can be mixed with water for a protein shake. Protein powders typically come as unflavored or flavored, and the flavored versions may include added sugars or alternative sweeteners.
You may prefer a flavored casein protein powder when using the powder in a shake, but unflavored options should work fine when added into other foods.
Here are a few ways to incorporate casein protein into your diet:
- Add it to oatmeal
- Blend it into a smoothie with fruit, greens, milk, and nut butter
- Make homemade protein-packed pancakes or waffles by adding protein powder to the batter
- Mix it into muffin batter
- Make no-bake protein bites for a satisfying snack
Casein protein is found in milk and is a complete source of protein that can help you build muscle and recover from workouts. It’s a good option for those with lactose intolerance who are sensitive to whey protein, but it isn’t suitable for those with a milk allergy. Besides using it in a protein shake, you can add casein protein powder to smoothies, baked goods, or oatmeal for a protein boost.