Whey Protein vs Casein Protein

Protein powders form the largest component of the supplement market. If you walk through a supplement store you’ll find more brands, types and flavors of any other supplement. Most people end up purchasing a product with branding that attracts them, the flavor they prefer and how well the powder mixes.

Whey and casein are the most common protein powders, and there’s a bit of debate about which is better. Just like anything in nutrition, the better product is the one that better suits your needs and goals. Understanding what the product is will help you make those sorts of decisions.

The Facts

Protein powder is simply protein that is processed and dried to make it more convenient to package and consume. These powders come from a variety of food sources such as dairy, eggs, soy, peas and even beef. But for the purpose of this article I’m covering whey and casein which are both dairy-based powders.


This is the most common protein powder and is the liquid by-product of making cheese. Whey accounts for about 20% of the protein found in cow’s milk. Whey includes all the essential amino acids and BCAAs and that’s partly why it is so popular. Its amino acid profile makes it really good for protein re-synthesis and therefore muscle recovery after training.

Whey digests quickly, causing a rapid increase in amino acid levels. Amino acid levels peak at approximately 90 minutes after ingestion, but drop quickly thereafter.


Casein constitutes 80% of the protein found in cow’s milk. It also contains a good blend of non-essential and essential amino acids, and BCAAs. However it contains a lower percentage of BCAAs than whey protein.

Casein is a slow digesting protein. The slower digestion creates a slow and steady release of amino acids that lasts for up to seven hours. The slower release of amino acids means that casein is less effective than whey in protein re-synthesis, but it reduces protein degradation more than whey does.

Which One Should You Use?

As you can see, each has different effects and the effects of each are valuable. So it will come down to your needs. If you are happy with your body composition and just need a supplement to help with recovery, then whey is a good choice IF you are having it immediately after training AND are following that with a balanced meal about 60 minutes later.

If you need a supplement to help you increase your protein intake at meals or are looking to increase your body weight, casein is a winner. It is too slow digesting to be used as a post-workout protein source, but as a bedtime snack you’ll be supplying your body with a steady flow of amino acids while you sleep. Sleep is the optimal time to repair and grow muscle.


Whey is best used as a post-workout protein source and for muscle repair. Casein is a convenient (and occasional) protein replacement for meals and works better to prevent muscle breakdown. Because of its slow digesting nature it also contributes to muscle growth.

Always remember that you don’t deserve supplements until your nutrition is dialed in, and that when you do begin to use supplements use quality products that contain minimal additives.

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