Protein supplements are common practice among many gym goers as a way to ensure they are meeting their protein needs to build muscle. 

Most protein supplements are made from milk proteins, such as casein and whey. But what are the differences between the two and is one better than the other? Let’s take a deeper look. 

What Are Casein and Whey Proteins?

Casein and whey are both forms of protein that come from cow’s milk. Both can be found in protein supplements but typically have different uses because of the way they are each digested in the body.  

Origins and Composition

Casein and whey are byproducts of cheesemaking. When enzymes are added to cow’s milk to produce cheese, the casein becomes coagulated and forms a solid known as curds while the whey protein remains liquid. These byproducts are then dried and processed to create a powder to be added to supplements.

Digestion and Absorption

One of the biggest differences between casein and whey protein is how they are digested and absorbed in the body. Whey protein digests a lot faster than casein and is therefore ideal for those to consume immediately post-workout for muscle growth [1]. 

This is because whey protein contains more branched-chain amino acids (BCAAs) leucine, isoleucine, and valine which are believed to boost muscle protein synthesis (MPS), particularly leucine [2, 3].

Whey protein is believed to digest within 90 minutes while it can take casein up to 5 hours. Casein contains higher levels of the amino acids histidine, methionine, and phenylalanine and is better at providing a slow and steady release of amino acids which is more optimal for post-exercise recovery if taken before bed [1, 4].  

Comparing Casein and Whey Protein

Whey and casein differ in their rate of absorption and their amino acid profile, but how does this compare when it comes to the benefits of each of these products?

Benefits of Whey Protein

Because whey protein is rapidly utilized by the body, it’s the most optimal form of protein to be used for individuals looking to boost muscle growth. 

It includes higher proportions of BCAAs, including leucine which is associated with stimulating MPS (the building of new muscle tissue). High levels of leucine may also help to protect against muscle breakdown to aid in faster post-workout recovery [5]. 

Benefits of Casein Protein

Casein is digested significantly slower than whey protein which allows for a slow and steady release of amino acids instead of a spike. 

This helps to increase satiety and aid in post-workout recovery, particularly before a state of fasting such as sleep. If you are someone who prefers to work out in the evenings before bed, casein is a better option than whey for MPS and post-exercise recovery [6].

The Synergistic Benefits of Combining Casein and Whey

If casein and whey protein have different benefits for muscle growth and recovery, can they be combined to have enhanced benefits? 

The answer is yes! Combining whey and casein can provide even further benefits for those looking to get more out of their workouts.

Enhanced Muscle Growth

Both casein and whey protein provide several benefits for enhancing muscle growth when consumed along with regular resistance training. Combining the two proteins may have an even bigger impact. In fact, it’s common for many athletes to mix whey and casein proteins to reap the advantages of both.

Whey protein provides a quick dose of amino acids, including the BCAA leucine to help initiate MPS while casein allows for a slow release of amino acids over time to help you repair muscle tissue after you exercise. This is especially helpful if you are going a long time between meals, such as with sleep so avoid missing out on muscle gains.

Improved Recovery

Whey protein boosts muscle anabolism (building new muscle tissue) throughout the day while casein helps to reduce muscle catabolism (breakdown). So one helps to build more muscle while the other protects from muscle loss meaning that combining the two can provide significant enhancements to muscle growth and recovery overall [7].

Practical Tips for Using Casein and Whey Protein

Whether you are interested in taking whey protein, casein protein, or mixing the two, below are some tips for using these valuable and convenient proteins to your advantage.

When to Take Each Type

The ideal timing to take protein supplements, regardless of which type, has been widely debated and newer research has found that total daily protein intake is more important. However, taking protein supplements right before or after your workout appears to be the most widely accepted time frame among experts to get the most benefit.

As mentioned earlier, the best time to take casein is if you are going to be unable to eat or fasting for a longer period such as with rest after your workout. Casein takes longer to digest so it can provide a slow and steady release of amino acids to avoid muscle breakdown when you aren’t eating. If you are a nighttime gym goer, casein is a good fit for right before bed.

Whey protein can be taken at any time of day but it is most effective when consumed shortly before or after your workout to help replenish your muscle tissue [8].

Recommended Dosages

If you are trying to build muscle, the optimal intake range of protein for someone who is participating in regular resistance training exercise is 1.6-2.2 grams per kilogram of body weight per day [9, 10].

That means if you weigh 165 pounds, you should be trying to consume somewhere between 120-165 grams of protein per day. It is recommended this is evenly distributed throughout the day versus in large quantities at one time. 

For example, this same individual might aim to consume 40 grams of protein per meal with 1-2 snacks in between meals that contain 10-15 grams of protein each or a protein supplement between meals pre- or post-workout.

Protein recommendations for non-active individuals vary greatly with the recommended dietary allowance (RDA) for protein to avoid nutrient deficiencies set at 0.8 grams per kilogram of body weight per day. 

If that same individual mentioned above was not active, this means they would need to consume at least 60 grams of protein per day to avoid developing a protein deficiency. Most people, even if they aren’t very active, would likely benefit from consuming more protein than the RDA [11].

Conclusion

Both whey protein and casein provide excellent benefits for muscle growth and complement each other when combined. You don’t have to choose between one or the other, in fact taking them together may provide greater benefits for gaining lean body mass.