Whey vs. Casein – Which Protein to Take

Whey vs. Casein – Which Protein to Take
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Going to buy a protein powder or supplement can be mind numbing, what with all of the different brands and types of proteins. Furthermore, there is a big debate about which is better, whey or casein protein. What’s interesting is that neither or better or worse for you, both whey and casein have their own benefits. It’s more about when to take which protein and why you’re taking it. In this article we’ll go in depth about whey vs casein and how you can navigate consumption and purchasing.


Whey is perhaps the best known type of protein, and is the most widely sold. It makes up a good number of protein supplements and you’ll see it in big bold letters on many protein bottles. It’s derived from cheese production, basically the powdered form of parts of the liquid that’s left over when cheese is made.

Between casein and whey, whey is the faster metabolizing protein and because of this has become known as “fast acting” protein or “fast protein”. Now what we mean by metabolizing is the amount of time needed for the whey to be digested, absorbed into your blood stream and taken up by your bodily tissue for use. It takes about 20 minutes for almost all of your whey protein to be taken in and moving throughout your body.

Between 20 and 40 minutes later your amino acid levels will be high and 20 minutes after that (1 hour after consumption) it wall have gone through protein synthesis, oxidation, or any other processes.

Because of the speed that you body takes up the whey protein it’s great for an after workout boost or even in the morning when you’re really trying to push protein to your muscles for recovery. Whey is even faster than most of the meats that you may eat and certainly faster than casein when it comes to metabilization.


Casein is similar in benefits, but quite opposite when it comes to protein uptake. While it takes 20 to 40 minutes for you to reach peak blood amino acids when taking whey, it can take up to 3 to 4 hours for you to synthesize casein and to reach peak blood amino acids.

Casein slows the rate of protein breakdown which is kind of like a “slow release”. This along with it’s longer synthesizing time and uptake is why casein has been coined “slow protein”. Since muscle growth is based on a balance of protein synthesis and breakdown this is actually good thing, your muscles can get what they need for a longer period of time.

So it may seem like using casein to slow breakdown and whey to speed protein synthesis is a good combination. This is the right idea, but you may not want to take them all at once because you’ll end up just peeing out a lot of the protein since your body won’t have a chance to digest and metabolize it all at one.

Uses and How to Consume

How and when you’re taking protein and your overall fitness goals should dictate which protein to take and when to take it. If you’re simply looking for a protein boost after a workout or in the morning, you should definitely opt for whey protein and you may not need casein protein. If you’re looking for a protein to take at night to stimulate muscle growth, you should opt for casein.

If you’re looking to gain some serious muscle it’s a good idea to have a good blend of both in your diet. Now you don’t want to just take both whey and casein at once because casein has a coagulative property, making it tar up in your stomach. This is why you might feel bloated or slowed down after taking casein.

Instead, you should take whey protein after eating or after working out. This will help you body reach peak amino acid levels right away. 2 -3 hours later your blood amino acid levels will be dropping. At this point you can take a serving of casein protein as it’ll slowly raise your blood amino acids backup without making you feel slowed down. You’ll also get the benefit of the slowed protein breakdown while your body is synthesizing the whey protein.

Bottom Line

No one protein is necessarily better than the other. In the great debate of whey vs. casein, it really comes down to you, and your goals. Whey is the faster acting protein, metabolizing and uptaking quicker in your body, while casein is the slower acting protein, helping slow protein breakdown.

If you’re not looking to build huge amounts of muscle, or are using protein as a meal replacement the type of protein will not matter as much, as long as you’re getting a healthy dose, though many opt for whey. If you’re looking to build muscle, having a good mix of both casein and whey protein at the correct times while optimize your body’s ability to synthesize and build muscle.

With that being said, be sure to also have real, whole proteins from things like meat, dairy, soy, or vegetables. Whey and casein are great supplements and additions to these foods, but having whole foods is till very important.

Whichever you choose to take, make sure you have the right diet and exercise plan. Modern Fit offers tailored diet and exercise plans to help you achieve your goals realistically and effectively. 

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