Animal source proteinProtein

Casein Vs. Whey Protein

Milk protein: Understanding types and differences of Casein and Whey

So you may be someone who has heard a lot about the many different supplements out there in muscle and strength building, specifically protein supplements. There are a few different types of protein that have vastly different uses and properties, and it is important to know these differences to ensure full effectiveness. So where are Whey and Casein protein found? Well- they are both found in dairy (specifically milk) products. Casein protein accounts for the largest percentage of the total protein in milk, being about 80 percent of that number. Whey accounts for the extra 20 percent. As I said before, these proteins are different in their makeup, and how they affect and aid the body.

Breaking down the Differences between Whey and Casein

Whey protein

Whey protein has long been a popular supplement among many bodybuilders and health nuts alike, and there is a good reason behind its popularity. Whey is so well known for its ability to enter the bloodstream extremely quickly. This means the amino acids within the protein start working to help repair your muscles quickly- and this is one of the main reasons Whey is such a popular post-workout supplement.

After breaking down muscle fibers during a workout, you need to get something in your system that is going to start repairing those muscles ASAP. This is where whey comes in- as no other protein is as good as whey for getting this job done. Whey has no known long term side effects, is easy to mix and digest, and is a favorite for all who take supplements.


Casein protein is not nearly as popular as its counterpart, although has been becoming a bigger part of body building in the past few decades. Much like whey, casein protein also has its origin in milk- although is extremely different in its physical properties. Unlike whey protein, casein is not easily digested in the stomach and actually forms clots.

Many of you have seen what milk looks like when it curdles- this is actually the true form casein takes when an enzyme is introduced. This clotting of the protein is what makes it key as a supplement. After consumption, Casein has the ability to stay in the stomach for several hours at a time, slowly giving off its essential amino acids. This comes at a price, however, because casein is not quickly absorbed into the bloodstream and doesn’t do much in muscle fiber synthesis and repair.

Because it takes such a long time to fully digest, casein is a great protein to consider when you’ll be going long periods of time without any intake of food- like when you go to sleep. Casein can keep working to fight the breakdown of muscle tissue when your body needs it the most.

Both Casein and Whey Proteins can work together almost symbiotically. The short term, quick release of whey helps muscles to immediately start recovering, and the long term and slow absorption of casein can ensure this process continues for a long time.

Summary of benefits: Whey and Casein


  • Quickly absorbed within the body
  • Works to start repairing muscles right after consumption
  • Easy to digest and mix
  • One of the safest supplements, with no long term side effects
  • Very widely used and accepted
  • Does not stay in the body for very long


  • Slowly absorbed within the body
  • Works over a period of several hours to fight muscle tissue breakdown
  • Harder to mix and can sometimes cause stomach aches
  • Does not support muscle tissue growth or synthesis
  • Takes a while to begin taking effect
  • Long term effects are harder to determine, although is just as “safe” as Whey

Which is right for YOU?

Because they do two different jobs, you may be asking yourself whether Casein or Whey is better for you to be taking. Well the answer is- BOTH. These two proteins seem like they were almost meant to be taken together- having a combination of protein that can enter the bloodstream quickly, promote muscle synthesis AND stay there for a long time while fighting muscle breakdown is extraordinary. There is no surprise many top body builders, MMA fighters, etc make use of both proteins in their diet.

A few more things to consider

Although whey and casein are great supplements- they are just that. Supplements. Trying to take any supplement in place of real food is never a good idea, you should always strive to get the proper nutrients the right way.

Remember that each of these proteins DO have DIFFERENT applications- they should be taken at different times and for different reasons. Strive to stay away from marketed supplements that are a blend of these two proteins. Whey is a protein you should be taking right after your workout, or perhaps in the morning as one of your meals. Casein should be taken over a period where you know you won’t be eating for a while- like right before bed.

Do a little bit of homework, and take the time to experiment what supplements work for you and your diet and exercise plans!

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