Which is Better: Whey Protein or Casein?

Which is Better: Whey Protein or Casein?

If you go to the gym regularly, you’ve definitely seen protein powder before. Heck, you may even use one right now.

After all, protein powders can be great for post-workout recovery and increasing overall protein intake. But, with as many different types of protein that are out there, it can be hard to know which to take. On top of that, not all protein powders are created equal.

The truth is, some protein powders can be more helpful than others. On top of that, some protein powders can be more ideal in certain situations.

That’s definitely the case for the two types of proteins I’m going to talk about today: Whey Protein and Casein. Believe it or not, both of these proteins come from the same source. That's right - whey protein and casein protein both come from milk.

As humans, we can benefit greatly from both of these proteins. But, which one is better: whey protein or casein protein?

Well, I wouldn’t say one is necessarily better than the other. That would be like comparing hiking boots to running shoes. Whey protein and casein protein can each be the better choice in different scenarios.

In this article, I'm going to cover everything you need to know when it comes to whey protein and casein. We'll compare the similarities, differences, and the best times to take one over the other.

First, let's start with the similarities between whey protein and casein.

What Are The Similarities Between Whey Protein and Casein?

As I’ve already established, whey protein and casein both come from milk. That’s not the only way they’re similar though.

For one, whey protein and casein are both considered high-quality sources of protein. But what is it that makes a protein high quality?

You see, it's not just about how the protein is processed and handled. What protein quality actually refers to is 2 things:

• The amino acid profile
• The bioavailability of the protein

There are 20 amino acids, and 9 of them are considered essential. These 9 amino acids are essential because we MUST get them from our diet. Believe it or not, our body can synthesize the other 11 amino acids on it's own.

A protein source that has all 9 of the essential amino acids is what's called a complete protein source. So, having a high concentration of these amino acids is part of what makes a protein source higher quality.

When it comes to bioavailability, this refers to how easily your body can absorb and use the protein. Whey protein is the most bioavailable protein source there is with a biological value score of 104 (1). Casein isn’t too far behind though, with a score of 77.

Don’t let that 27 point difference fool you though. Our bodies are able to absorb and use the amino acids from casein quite well too.

Studies show that both whey protein and casein can help you build muscle and strength, lose body fat, and increase performance (2). So, both whey protein and casein can help you achieve your fitness goals.

Now, that's pretty much where the similarities end. Their differences are the reason why it's recommended to use them at different times.

Let's talk about that next!

What Are The Differences Between Whey Protein and Casein?

Whey protein and casein are both great options. They are highly-bioavailable, and both contain all 9 essential amino acids.

However, that doesn't mean they are the same. Whey protein and casein have different benefits, and are ideal in different situations.

For example, one of the biggest differences between whey protein and casein is the digestion rate.

Whey protein is a protein that your body digests and absorbs rapidly. The amino acids from whey protein make their way into the bloodstream and muscle quickly. This is why it’s often labeled as a “fast protein” (2).

Casein, on the other hand, is a protein that digests much slower. It takes a long time to fully break down and get absorbed into the bloodstream. This is why casein is often labeled as a “slow protein” (2).

This difference in digestion alone is a big reason why each protein is better in different scenarios.

Let's use post-workout for example. When you work out, there are tiny microtears created in your muscle fibers. This damage is something you want to start repairing as quickly as possible after a workout.

In this case, whey protein can be much more ideal. Due to the digestion rate, and the amino acid profile, whey stimulates muscle protein synthesis more than other protein source (3).

To keep it simple, muscle protein synthesis is the process of building and repairing muscle tissue.

So, after a tough workout, that’s exactly what you want. Whey protein is king in the post-workout arena. However, that doesn't mean casein can't be helpful as well.

Casein isn’t water soluble, and it thickens in the body once ingested. This is what creates a slow release of amino acids over time.

To put it simply: Casein, like whey protein, also stimulates muscle protein synthesis. The difference is that it prolongs and draws out this process (2).

Whey protein does the opposite. It spikes muscle protein synthesis quickly, and doesn’t sustain it for quite as long.

This makes casein much more ideal at bedtime. As you sleep, your body is slowly absorbing those amino acids. This can help feed muscle tissue for longer throughout the night.

As you can see, whey protein and casein are both great sources of protein. The best time to use them just happens to be different.

Should You Ever Mix Whey Protein and Casein?

So, would it ever make sense to mix whey protein and casein? The answer is yes, and this is where things get interesting.

It may sound a little counterintuitive, but I promise you, it isn’t. There is a huge benefit to mixing both types of protein in the same blend!

Many protein supplements include a protein called milk protein. This is whey and casein together in the ratio they are found in milk. The ratio in milk is 80% casein, and 20% whey protein.

When taken together, the rate of muscle protein synthesis after 1.5-2 hours is higher than taking whey protein or casein alone (3)!

Whey protein thrives earlier on with regards to the rate of muscle protein synthesis. Casein thrives a little later. With the combination of the two, you get the best of both worlds for the intermediate time frame.

But, why is that important? Why does protein intake even matter?

Well, if you have any fitness goals, your protein intake should matter quite a bit to you. Protein is an essential piece of the puzzle when it comes to building muscle and losing body fat.

Your muscles are made of protein and water. So, if you want to build muscle, you’ll need enough protein to do it.

When it comes to fat loss, protein can help in several ways too. That's because muscle tissue burns calories 24 hours a day, even at rest. Not only do you need protein to build muscle, but you also need protein to maintain muscle.

If your goal is fat loss, holding onto and building more muscle can help you burn more calories every day. Since you have to burn more calories than you eat in order to lose fat, this can be very advantageous.

Keeping your protein intake high can help your body preserve more lean muscle while you're losing weight. In turn, this helps keep your resting metabolism higher and can sanction more of your weight loss to body fat!

Also, protein is very filling. Eating protein can help you feel more satiated and keep cravings to a minimum. Plus, did I mention that your body burns more calories digesting protein than any other macronutrient?

Whey Protein and Casein: Putting Them to Good Use

If you struggle to get the protein you need through whole foods, that's where whey protein and casein can help.

To take things a step further, if you have fitness goals, then I’m sure you want the best results possible. Truthfully, you can earn results using whey protein, and you can earn them using casein.

But if you want to maximize your results, you'll want to use each one at the right time.

Here is a quick guide to exactly what protein you need, and at what time they are best used!

Whey Protein or Casein: The Best Protein For Post-Workout

For post-workout recovery, the most ideal thing to use is a whey protein isolate with a high glycemic carb. Remember, whey protein will digest rapidly and spike muscle protein synthesis quickly.

A whey protein isolate is just a type of whey protein that has most of the fats and lactose extracted. This can give whey protein an even more rapid rate of assimilation.

I use the Post Workout Stack after my workouts, which has made a noticeable difference in my soreness and results! This stack is the combination of Phormula-1 and Ignition.

Phormula-1 is the whey protein isolate, and Ignition is the high-glycemic carb. For more information about the Post Workout Stack and how it can help, you can check it out here!

1st Phorm Post Workout Stack

Whey Protein or Casein: The Best Protein For Meals and Snacks

If you’re about to miss a meal, or you need something between meals, you’ll want a blend of whey protein and casein. This blend can help stretch out the process of muscle protein synthesis, and more closely mimic the digestion of whole foods.

Whey protein provides amino acids earlier, while casein slowly releases amino acids for longer. The whey and casein blend I use is Level-1. Trust me, the flavors are incredible! I certainly wouldn't be able to hit my protein goal every day without the convenience it has to offer.

You can check out the Level-1 here.

Whey Protein or Casein: The Best Protein For Bedtime

If you’re looking for the most ideal protein to use before bed, I’ve got you. You could use either a pure micellar casein powder, or you could use a whey/casein blend once again.

Both options will extend the muscle-building process throughout the night, and you really can’t go wrong with either. Personally, I use the Level-1 here when I need it as well.

Given the fact that Level-1 has the best of both worlds, it's a no-brainer for me! I get the benefits of the slow-digesting casein, as well as the benefits of the more bioavailable whey protein.

Maximizing Your Results

Yes, whey and casein protein powders can make a big difference in your results. However, supplements are tools, and you should treat them as such.

No supplement is meant to replace your entire diet and exercise protocol. In fact, supplements only exist to help you fill in gaps where you may be falling short.

If you're struggling to see results, or aren't sure where to get started, that's what we're here for! We even designed the 1st Phorm App to help with exactly that. It's the most complete all-in-one fitness app you'll find.

Inside the app, you'll get your own certified advisor to help you along every step of your journey. You'll also get the ability to track your food, get a workout program for your goals, and so much more!

Download the 1st Phorm App now and give your goals your best shot. If you have any additional questions, or need help, let us know! We have a full team of NASM Certified Personal Trainers and Nutrition Coaches you can call at 1-800-409-9732, or email at CustomerService@1stPhorm.com.

If you're looking to add whey protein or casein protein to your regimen ... we have a lot of great options for you.

For an exceptional post-workout whey protein isolate, we have Phormula-1.

For a blend of whey protein and casein to get more protein throughout the day, we offer Level-1.

You can also shop all of our protein supplements here.

Level-1 Meal Replacement Protein Powder


(1) Hoffman JR, Falvo MJ. Protein - Which is Best? J Sports Sci Med. 2004 Sep 1;3(3):118-30. PMID: 24482589; PMCID: PMC3905294.

(2) Wilborn CD, Taylor LW, Outlaw J, Williams L, Campbell B, Foster CA, Smith-Ryan A, Urbina S, Hayward S. The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes. J Sports Sci Med. 2013 Mar 1;12(1):74-9. PMID: 24149728; PMCID: PMC3761774.

(3) Kanda A, Nakayama K, Sanbongi C, Nagata M, Ikegami S, Itoh H. Effects of Whey, Caseinate, or Milk Protein Ingestion on Muscle Protein Synthesis after Exercise. Nutrients. 2016 Jun 3;8(6):339. doi: 10.3390/nu8060339. PMID: 27271661; PMCID: PMC4924180.