Casein Protein Vs Whey (Key Differences Compared)

Protein powder plays a massive role in how our body functions as well as how it looks. However, it can be confusing when discussing casein protein vs. whey protein. Both are made from milk and contain essential amino acids. They are essential in building, maintaining, and repairing muscle and offer greater results and health benefits than what whole food alone can accomplish in many ways.

Milk is approximately 80% casein and 20% whey. During cheesemaking, milk is heated, which results in the whey (liquid) and the casein (solids) to separate. If you're seeking in-depth knowledge about casein protein and whey protein and the differences between them to help determine which is best for your goals, then keep on reading.

As we just talked about, casein is 80% of the milk protein and is digested more slowly, preventing excessive protein breakdown. Not only is it an excellent source of protein, but it also offers a steady supply of amino acids throughout the day/night required for muscle growth and repair.

Casein also plays a big part in infant formulas, which are "harder for infants to digest," making it ideal for older infants. However, it still offers essential amino acids which can help with infant development.

Let’s take a look at the 2 main forms of casein:

  • Micellar Casein 
    This is the “original form” of casein found in milk. When we consume it, it comes together to form a larger clump which takes much longer to digest – up to around 7 hours. This offers a steady supply of aminos while still keeping the body in an anabolic state
  • Casein Hydrolysate  
    This is a pre-digested, rapidly-acting protein very similar to whey in this regard. It helps boost recovery and avoids muscle catabolism.

How Effective is Casein Protein at Muscle Growth?

Casein is incredibly effective at helping muscle growth due to it containing all essential amino acids our bodies are incapable of producing naturally. It also contains a high quantity of leucine, which fires up muscle protein synthesis.

It's also highly effective at lowering protein breakdown, which happens when our bodies are tired and more so when we're active, like participating in regular exercise. This is why having a protein shake or a scoop of casein powder mixed with Greek yogurt before bed is ideal. When we’re sleeping, we aren't eating/are fasting, and during this time, our body can start to break down protein.

Casein Protein Vs Whey

Other Benefits of Casein Protein

  • Lasts Longer In Your System  
    Not every protein will last the same amount of time in the body. Instead of offering a quick spike of amino acids, casein instead supplies a slow and steady amount that can last the entire time you’re at work or asleep! Not to mention, you’ll feel fuller, longer.
  • Yields Greater Gains  
    If you’re looking to put on some mass, you will see better results if you consume casein along with whey instead of just whey alone. It makes sense, as casein helps protect the muscle mass you already have.
  • Improves Metabolic Rate  
    Do you want to improve your body composition? Then you’ll be happy to know that studies have suggested casein can increase metabolic rate while you’re asleep and can increase satiety levels over a third.
  • Yields Greater Strength  
    Want to hit a new one-rep max or just impress your gym partner? Then you need to be grabbing yourself a new tub of casein powder. Studies show that casein doubles the effect that whey protein has on leg, chest, and shoulder strength. As heavier lifts directly correlate to more muscle growth, it’s crucial if you’re trying to gain mass
  • Improves & Protects Your Teeth  
    You’ll definitely need some pearly whites to pair with those new cuts, and yep, casein can do that too. Research has found that the proteins in casein can reduce or prevent enamel erosion. If you drink a lot of coffee, fruit juices, or other acidic beverages, then this can really help keep your teeth in good shape

Whey Protein Powder Overview

Whey protein is a bunch of proteins isolated from the liquid part of milk during cheese production. It's like if you have a yogurt container: the solid yogurt is casein while that liquid that settles on the top is whey. To become a whey protein powder, this liquid is processed so it can then be used in shakes and protein bars.

Whey is an easy way to keep protein intake up, which can be harder to do by just consuming whole food. A single scoop of whey is usually around 120 calories and offers around 20-25 grams of protein. To get that same amount of protein from natural food sources, we'd have to consume many more calories.

Whey protein is excellent at igniting muscle growth in humans, thanks to its high leucine and cysteine content. As cysteine is so helpful in boosting strength, you can imagine it's a must-have for anyone at the gym. Let's take a look at each kind of whey protein:


This is around 70% - 80% protein. Some contain lactose and fat, though they are known to have the best flavor by far.


This contains around 90% protein or more, containing less lactose and fat. However, it also contains less of the valuable nutrients our body likes so much in concentrate.


Also known as hydrolyzed whey, it’s grown wildly in popularity in recent years. It’s pre-digested for quicker absorption, causing a 28% - 43% larger spike in insulin levels than isolate. This makes it ideal for right after your workout, immediately supplying essential aminos and proteins to start on recovery as soon as you’re done.

How Effective Is Whey Protein for Muscle Mass & Strength?

As whey is so effective in stimulating growth in humans, it’s perfect for developing muscle mass. Let's take a look at exactly what makes whey such a premium selection among bodybuilders, fitness models, and other athletes alike.

Building Blocks

It offers protein and all 9 essential amino acids, which are all necessary for elevated muscle building.


As it helps boost the release of anabolic hormones that ignite muscle growth, it gets your entire body on board to help build muscle and strength.


As previously mentioned, whey is very high in leucine which also helps stimulate muscle protein synthesis.

Quick Absorption

Whey is absorbed incredibly fast, which means your body can use it right away to begin repair and, thus, grow and strengthen your muscles.

Due to all of these characteristics, whey protein is ideal for taking around a workout – namely within half an hour after you finish your workout. However, you can really take it whenever you want. I enjoy a scoop of it mixed with an egg or two for some "protein pancakes" and take another scoop in water after I'm done with my lifting for the day. 

If you aren't used to consuming higher amounts of protein, though, it's best you start out with just one and see how your gastrointestinal tract does. "Individuals consuming higher protein intakes may adapt to digest/absorb protein more efficiently," says NASM.

Whey Protein Powder Overview

Other Benefits of Whey Protein Powder

Aiding weight loss

Out of every macronutrient (fats, carbs, proteins), protein is the one that’s the most satiating. Moreover, it can increase energy burning by up to 80 – 100 calories a day and can keep you from eating around 400 less a day! That on its own is a big deal regarding weight loss, considering there are 3,500 calories in a pound of fat.

Lowering cholesterol

Consuming whey protein has been shown to lower cholesterol, blood pressure, blood sugar, and reduce symptoms of stress and depression. Even The British Journal of Nutrition found that there was a significant decrease in total cholesterol and LDL cholesterol in just a few months of beginning to take the protein.

Muscle building

Most people start taking whey protein powder because they want to gain muscle mass. While it’s definitely helpful for this purpose, there’s a common misconception about women that it will make them look like Arnold. This simply isn’t true – whey can actually create a more sleek, toned figure in women.

Wound healing

Studies have shown it can also help protect against cancer, increase bone mineral density, improve immune function in HIV patients, and much more! As a wonderful source of glutamine and branched-chain amino acids, it aids with cell growth and repair.

Athletes, in particular, find incredible benefit of using a whey protein powder supplement. One of the most attractive features is its incredible speed of absorption, which helps almost immediately in recovery, supplying muscles with the necessary "food" it needs to recover in a shorter amount of time and more efficiently rebuild strength and structure.

Casein Protein vs. Whey Protein: A Side by Side Comparison

Weight Loss

Both are effective for aiding weight loss; however, if you have a long time between meals, then you’ll probably be better situated with casein. As it keeps you feeling fuller, longer, it may steer you away from having cravings and eating something you hadn’t planned on.

Gaining Muscle

As whey can quickly spike amino acid levels in the blood, it’s an excellent tool to have for gaining muscle. While casein doesn’t have these properties, it protects the muscles you do have and helps prevent muscles from breaking down.

Gaining Strength

Whey and casein are pretty even when it comes to strength gain: they’re both beneficial but not so much one over the other.

Digestion Time

Whey takes about a mere 20 minutes to be digested and absorbed into the bloodstream, which is incredibly fast for any type of food product. Casein, in contrast, is slow digesting and takes around 2 to 4 hours.

Body Absorption

Whey is absorbed by the body in just 20 minutes, while casein takes a few hours to do the same.

Casein vs. Whey vs. Soy Protein

In terms of whey and soy protein, muscle mass gain is almost the same. It's absorbed at just a slightly slower rate than whey and a bit faster than casein.

However, whey and casein simply have a high quality of protein and are both more effective for weight loss. If you have a lactose intolerance, it could be a good idea, however.

People Also Ask (FAQs)

Can you take casein and whey combined?

You definitely can! In fact, casein and whey together have often proven to be the best combo for muscle strength and gain out there.

Do baby formulas have casein or whey?

They actually have both but are notably high in casein.

How long before bed should I take casein?

Many ask about casein protein vs. whey before bed. You should be taking it casein anywhere from 30 minutes to an hour before bed. Whey would probably be better to take in the morning or around your workout.

Can I drink whey protein without working out?

You absolutely can! You can have whey protein just about whenever you want. You can use it as a meal replacement, so long as you’re watching your macros.


We know that there’s a lot of confusion surrounding whey and casein protein powder and which is better for what. While they are very similar, there are many notable differences that we must know in order to select the ideal product for best results and make sure every minute spent in the gym is worth it. We hope our guide has helped you to do exactly that.

Last Updated on February 22, 2023

Paul J

Paul J

Paul J is is an ex-professional footballer who has seen a gym or two and is an expert at knowing what is required for home gym setups. When he isn’t testing out products for his readers, he’s usually going for a run in the park or out for coffee.