Whey Protein vs Casein Protein: Which is Best For What?

True Protein Blog Avatar Fallback reviewed by our Nutrition Team 12 April 2018

Find out what the fundamental difference is between our whey protein isolate (WPI90) and our casein (Night 85) proteins

Read More
Whey Protein vs Casein Protein: Which is Best For What?

If you’re looking to bulk up, both whey and casein protein will do the trick. However, there are differences between these two which affect the digestion rate, muscle growth, and use.


We’ve already discussed the benefits of whey protein which expand to more than just building muscles, and with this article, we want to offer a deeper insight and compare it to another highly beneficial protein - casein. While we have a variety of proteins in our protein powder range at our disposal, the two are by far the most frequently purchased and consumed ones.



WPI boasts 90% protein content for first-class results

4069 total reviews

Regular price
From $38.00
Regular price
Sale price
From $38.00
Quick Buy
Quick Buy

All you need to know about protein


First, a few introductory words on protein...


Every protein consists of carbon, hydrogen, oxygen, and nitrogen, while there are some which contain sulfur. These elements are also known as amino acids, and they are the building blocks of protein.


Essential amino acids cannot be synthesized by the body;


Nonessential amino acids are synthesized by our body and play an important part in the construction of our body’s proteins. 


Protein represents a source of energy in situations where your body faces a negative caloric balance, that is when your calorie intake is less than the amount you burn.


Allow us to explain this in more detail: There is an opposite link between your caloric intake and the actual protein requirement. If you absorb fewer calories, you’ll need more protein (and vice versa). For those experiencing a negative caloric balance, the protein requirement is even higher, especially if they consume low-quality proteins.


Athletes also need a greater amount of protein due to the fact that their physical activity levels are much higher. This especially applies to aerobic endurance training and resistance training. Namely, for athletes doing aerobic exercises, protein helps to repair tissue and its amino acids are used as fuel. For strength training, protein is essential when it comes to tissue repair and positive nitrogen balance maintenance.


Now that you are familiar with the basics, we can move on to the main reason we’re here: whey vs. casein.

Whey Protein


Whey protein is the best selling protein, most commonly found in supplement stores. Whey is a natural component of cow’s milk and it makes for 20% of its protein. It is also a byproduct of the cheese-making process.


What makes whey protein so popular is the fact that it’s consisted of all the essential amino acids, and it’s rich in branched-chain amino acids used in muscle protein synthesis.


Due to the fact that it contains more sulfur-based amino acids than casein, whey protein has a higher level of biological use than any other protein.


Lactose, minerals, vitamins, lactalbumin (like serum albumin) and traces of fat are also part of this protein’s structure.


Whey protein is considered a fast absorbing protein, which means it gets digested quickly. This process raises the level of amino acids in the body, and blood amino acid levels reach their maximum somewhere around 60 to 90 minutes after consumption. This high-level state doesn’t last for too long and can only be sustained for two or three hours.


When your body gets overrun by amino acids, a certain amount of protein gets oxidized and discarded as excess, and that is why whey protein is best consumed right after exercising. As a result of its fast acting nature, whey protein repairs muscle tissue by increasing muscle synthesis.

Lia cycling

Whey Protein Benefits

Whey protein is a powerful antioxidant because it increases glutathione levels. Glutathione is a tri-peptide which contains amino acid residue from the glutamic acid, cysteine, and glycine, and it plays an important role in protecting skeletal muscle, as well as the other tissue from oxidative damage.


Whey Protein Supplements


Whey protein isolate represents the best whey protein, due to its pure and concentrated form. This type of whey protein powder consists mostly of protein (more than 90%) and little-to-no fat and lactose.


Whey protein concentrate contains somewhere between 29% and 89% protein, which usually depends on the product. The lower protein levels, the higher the amount of fat and lactose.


Whey protein hydrolysates is another type of whey protein supplement that contains predigested whey in a form of peptides (small chains of amino acids). This product supposedly helps in better protein absorption.


Casein Protein: True Night 85




Slow releasing protein

192 total reviews

Regular price
Regular price
Sale price
Quick Buy
Quick Buy

Cow’s milk has a much higher concentration of casein protein, amounting to 80% of its total protein content. It contains a high-quality mixture of essential, nonessential and branched-chain amino acids.


What makes Casein protein different from whey protein is the fact that it has a smaller percentage of branched-chain amino acids which lower it’s biological utilization rate. That makes casein a slow-digesting protein - the body’s ingestion of casein amino acids is slower, keeping their levels normal and well-maintained throughout a longer period of time. Casein enables a steady elevation of amino acids, which can last up to seven hours.


Casein protein doesn’t have a sudden rise in amino acid levels, unlike whey.That is why less protein is oxidized and wasted, leading to a not-so-intense protein synthesis and reduced level of whole body protein breakdown.


Casein is an excellent form of meal replacement and it’s perfect for nighttime use. Because of its slow-acting nature, it’s not recommended for immediate use after a workout. Furthermore, it doesn't provide an instant benefit of muscle repair right after exercising.


The best time to use casein is right before you go to bed because the best muscle repair process occurs while you are sleeping, that is, when you are least active - here’s where casein steps in, providing the body with 7 hours of a gradual elevation of amino acids.

Casein protein benefits


Supplements daily protein requirements.

Has a high-quality mixture of amino acids.

Helps maintain muscle mass during a diet.

When used for baking, it can increase the meal’s protein value and add texture.


Casein Protein Supplements


Casein protein powder can be found both as an isolate and concentrate.


Micellar casein is concentrated in a form of micellar portions of casein. This type of casein protein gets digested more slowly, even slower than usual - up to 8 hours.


Caseinates are used as a primary source of casein in the majority of products, and the most common forms include calcium, potassium and sodium caseinates.


A hydrolysate is a form of casein which is easy to digest and is used for transforming protein cells into smaller peptides.


Making a shake

Ultimate comparison: Whey vs. Casein


According to a study conducted by McMaster University, whey protein is considered superior to casein because of its ability to enhance muscle tissue. Whey is also 20% higher in Leucine, which is essential for achieving the highest level of muscle protein synthesis. Products which contain leucine in high amounts are perfect for post-workout consumption since they are quickly digested. Leucine is also one of the most significant branched-chain amino acid which aids in muscle growth and recovery.


The greatest benefit of whey protein is its fast absorbing ability which increases muscle synthesis.


The one important advantage casein protein has over whey is the effect it has when taken before bed. The research mentioned above indicates that casein is more efficient in sustaining muscle protein synthesis and postponing negative effects on net protein balance over a longer period of time.


However, if you want the best of both worlds and are looking to achieve maximum results, try combining the two proteins.


Baylor University researchers compared the effects of mixing whey and casein protein against carbohydrate - the results were overwhelmingly positive and in favor of the combination.


Participants were subjected to similar diets and identical training programs. After supplementing with the mixture of these proteins, the results were as follows: an increase in several measures of muscle anabolism, including leaner muscle mass, tighter muscle mass, muscle strength, anabolic hormones and muscle-specific proteins.


Therefore, depending on what you want to achieve, consume these proteins separately, or combined. Both come with an enviable amount of benefits, you just need to figure out what suits your body best.

IMPORTANT INFORMATION: all content provided here is of a general nature only and is not a substitute for individualised professional medical advice, diagnosis or treatment and reliance should not be placed on it. For personalised medical or nutrition advice, please make an appointment with your doctor, dietitian or qualified health careprofessional.