Casein Protein Expert Guide: Types, Benefits, Dosages & FAQ

Casein is a calcium rich, slow digesting protein source that is anti-catabolic in nature. It remains a staple supplement for top bodybuilders, athletes and fitness enthusiasts.
  1. 1. What is Casein Protein?
  2. 2. Benefits of Casein Protein
    1. 2.1. Casein Benefits Review
  3. 3. How is Casein Protein Made?
  4. 4. What are Casein Hydrolysate and Micellar Casein?
  5. 5. How should I take Casein Protein?
  6. 6. When is the best time to take my casein protein supplement?
  7. 7. Whey vs. Casein
  8. 8. Best Casein Protein Powders
  9. 9. Casein FAQ
  • What casein protein powder is, and how it is different than other protein sources like whey protein.
  • The different types of casein protein that are available.
  • The major benefits of casein supplementation for those looking to build muscle and/or burn fat.
  • The recommended amount of casein protein to take, and the optimal times to take it.

Your endeavor to achieve your physique and fitness goals starts with proper nourishment. When you push your body physically the demand for protein can significantly increase; this increased demand can make it cumbersome to meet your protein needs purely with solid food sources such as poultry, beef, eggs, etc.—this is where supplemental sources of protein come in handy.

Many people are familiar with whey protein’s benefits since it is quickly absorbed and highly bioavailable, but casein protein can be an even more viable option in many situations. This guide will serve as a complete resource to supplemental casein protein by expanding on what casein protein is, how it’s produced, its benefits, how it differs from whey protein, who should take it, and which products we recommend.

What is Casein Protein?

Casein proteins are the primary constituents of animal milk proteins (accounting for roughly 80% of the total protein content), and are often touted for their exceptionally slow rate of digestion and absorption. (1) The specific fractions/types of casein protein (denoted alpha s1/s2, beta and kappa) differ in proportion according to the species from which they're synthesized; the primary source of casein proteins in human nutrition come from dairy cattle. *Throughout the rest of the guide the term “casein” will be in singular form but will encompass all 4 fractions of casein proteins.*

A distinguishing characteristic of casein protein is its insolubility at lower pH (such an environment would be that of stomach acid). The mechanism for casein’s slow absorption arises from its coagulating properties when exposed to stomach acid; the resulting coagulant precipitates and creates a slow, sustained rise of plasma amino acids. (2) It is for this reason that casein protein is suggested to have longer-lasting anti-catabolic properties (upwards of 7-8 hours post ingestion) compared to a rapidly-digesting protein such as whey. (3)

Benefits of Casein Protein

The benefits of casein protein are numerous, especially for those who are following an active exercise regimen. Much interest in casein protein and its correlation to muscle hypertrophy arose from early studies comparing fluid milk ingestion to soy proteins. It has been elucidated in a plethora of studies that milk proteins are superior to soy/vegetable proteins in terms of promoting muscle hypertrophy after resistance training. (4, 5) All of the major animal milk proteins (i.e. casein, whey, albumin) are capable of promoting muscle protein synthesis to some degree via activation of the mammalian target of rapamycin (mTOR) pathway and they are complete proteins (meaning they possess all of the essential amino acids). (6)

While casein is certainly effective at promoting muscle protein synthesis, one of its differentiating features is the ability to provide a sustained rate of amino acid uptake versus a rapid, transient increase that would arise from whey protein ingestion. (7) Given this, casein may be more beneficial to individuals who are looking for a protein supplement that can provide several hours of nourishment and satiety versus a quicker digesting protein like whey. As noted earlier, this gives casein longer-lasting anti-catabolic properties and is why people often refer to it as the optimal “bedtime” protein; casein’s prolonged digestion helps promote a positive nitrogen balance during extended hours of sleep. However, don’t constrain casein supplementation to just before bed, as it can be beneficial at most anytime of the day, even pre and post workout (*more on this in the When should I take Casein protein section). (8)

Another feature of casein protein is its rich calcium content (*see the Micellar Casein section below for more on why this is). Calcium is an essential mineral for bone health and research has suggested that in can enhance fat loss in overweight subjects. (9) For this reason, individuals that find they struggle to meet their daily quota of calcium intake through food sources could stand to benefit with a casein protein supplement.

Casein Benefits Review:

  • Stimulates muscle protein synthesis/activates mTOR pathway
  • Is a complete protein source
  • May be a useful appetite suppressor since it provides more enduring satiety than a rapidly-digesting source of protein
  • Provides anti-catabolic properties for longer periods of time than rapidly-digesting proteins
  • Is a rich source of calcium which may be beneficial for bone health and fat loss
  • Individuals looking a convenient and quick way to increase protein intake will derive the most benefit out of supplementing with casein protein. These include:
  • Bodybuilders & strength trainers
  • Athletes
  • Vegetarians
  • Recreational exercisers and those new to weight/strength training
  • Anyone else who is looking for a simple way to get more protein in their diet (*allergies notwithstanding)

How is Casein Protein Made?

Casein protein is found in fresh milk produced via mammals. The supplemental forms of casein are produced by various food technology methods including acidification, ultra-filtration, enzymatic hydrolyzation, salification and others. (10) Casein protein powders have a cream-like color and are bland in flavor/odor in their raw state. Casein protein supplements maintain a shelf life of approximately two years when stored in the original sealed container and kept at room temperature. (10)

What are Casein Hydrolysate and Micellar Casein?

Before we discuss the differences between these two forms of casein protein, a fundamental understanding of protein structure and digestion is necessary. Proteins are made up of many peptide bonds that conjoin amino acids via carbon-nitrogen bonds. These bonds are necessarily “lysed” (i.e. split) by the process of hydrolysis which subsequently increases free amino-acid concentrations in the blood. Hence, hydrolysis refers to the splitting of a chemical bond by an H2O molecule.

Casein hydrolysate (also sometimes referred to as hydrolyzed casein) is enzymatically hydrolyzed during processing to improve its rate of absorption. (11) The increase in digestion/absorption rate and amino acid delivery to skeletal muscle tissue arises from the fact that the protein structure is essentially “pre-digested” into smaller peptide fractions from its intact, original structure.

Micellar casein is a soluble, high-quality milk protein powder with a clean flavor. Micellar casein protein can essentially be described as the whole, undenatured form; in nature, most casein protein exists as what’s known as a casein micelle. (1) A casein micelle is a colloidal particle that biologically serves to transport insoluble calcium-phosphate complexes in liquid form to the stomach for clotting and subsequent digestion. In fact, over 90% of the calcium content in skim milk is linked with the casein micelle. (1) For this reason, as aforementioned in the benefits section, casein protein supplements can serve as potent sources of calcium.

How should I take Casein Protein?

Casein protein powder can be used in many applications just like the myriad of other protein powders. Many people like the convenience of having something available on the go so just mixing casein in sufficient fluid (roughly 8oz fluid for every 25g of protein content) with a spoon/blender/shaker is adequate. Due to its chemical properties, casein protein powder will mix a bit thicker than whey protein powders will, and the texture can sometimes be described as a bit gritty.

Furthermore, the characteristic coagulating property of casein protein when it’s exposed to acidic environments and/or high temperatures make it tricky to bake with or add to hot foods since it will tend to be insoluble and clump up. But a great application of casein protein powder (for those who like to get creative in the kitchen) is to make “protein pudding”, also colloquially referred to as “sludge”. Since casein powder will readily gel/thicken up when mixed in minute amounts of liquid this can be a nice treat for those who get tired of always drinking their protein supplements. Find out how to make protein sludge here.

When is the best time to take my casein protein supplement?

Casein protein is versatile and can be used virtually whenever you desire more protein in your diet. They are especially useful when prolonged periods of time without feeding are to be expected (such as before going to bed). Casein protein can also be combined with whey protein to enhance the anabolic response8; if you are seeking a great option for after a workout, try combining whey and casein protein supplements in a 2:1 ratio, respectively.

Whey vs. Casein

Whereas whey protein is readily acid-soluble (and hence creates a rapid increase in plasma amino acid levels), casein coagulates when exposed to acidic solutions and slowly precipitates, resulting in a more sustained rate of digestion. (11) High-quality proteins such whey and casein are capable of promoting muscle protein synthesis post-exercise by activating the mammalian target of rapamycin (mTOR) signaling pathway. (6)

While whey protein on its own has been shown to more effectively stimulate muscle protein synthesis directly after a workout (8), casein may actually serve as a potent adjunct to whey by enhancing the anabolic response to weight training. (6) Don’t think of it as an either-or issue; both casein and whey supplements are your allies in the battle to build your dream physique and they should be used in conjunction with one another.

To read more about whey protein’s, check out our Expert Guide here.

Casein FAQ

Is a casein protein supplement okay if I have an allergy to milk?

Unfortunately casein is not safe for consumption if you have allergic reactions to milk; the proteins in milk are known allergens.

Is a casein protein supplement okay if I am lactose intolerant?

Yes, casein is a protein in milk and has nothing to do with lactose (a sugar component of milk).

Do rice, soy, or almond milks contain casein protein?

No, these are vegetable/grain-based milk products and casein protein is found in animal-derived milk products.

How much protein should I aim for everyday?

This will vary according to your goals, lifestyle and metabolic factors. A good starting point for trainees is 1 gram of protein per pound of lean body mass.

I’m a vegetarian, can I use casein supplements?

Yes, casein supplements are a great source of protein for those abstaining from animal sources of protein.

Can’t I just drink milk instead of buying a casein supplement?

Yes, but it’s actually a better value in terms of price per gram of protein to use a pure casein supplement since milk contains other nutrients like carbohydrates and fats.

  1. Solutions, N. B. (n.d.). PRINCIPALS OF DAIRY CHEMISTRY. NEM Business Solutions Specialist in food industry CIP systems. Retrieved March 20, 2013, from
  2. Resource Library - Milk Composition & Synthesis. (n.d.). Animal Sciences Classes. Retrieved March 20, 2013, from
  3. Lacroix M, Bos C, Léonil J, Airinei G, Luengo C, Daré S, Benamouzig R, Fouillet H, Fauquant J, Tomé D, Gaudichon C. Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement.Am J Clin Nutr. 2006 Nov;84(5):1070-9. PubMed PMID: 17093159.
  4. Hartman JW, Tang JE, Wilkinson SB, Tarnopolsky MA, Lawrence RL, Fullerton AV, Phillips SM. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr. 2007 Aug;86(2):373-81. PubMed PMID: 17684208.
  5. Phillips SM, Tang JE, Moore DR. The role of milk- and soy-based protein in support of muscle protein synthesis and muscle protein accretion in young and elderly persons. J Am Coll Nutr. 2009 Aug;28(4):343-54. Review. PubMed PMID: 20368372.
  6. Reidy PT, Walker DK, Dickinson JM, Gundermann DM, Drummond MJ, Timmerman KL, Fry CS, Borack MS, Cope MB, Mukherjea R, Jennings K, Volpi E, Rasmussen BB. Protein blend ingestion following resistance exercise promotes human muscle protein synthesis. J Nutr. 2013 Apr;143(4):410-6. doi: 10.3945/jn.112.168021. Epub 2013 Jan 23. PubMed PMID: 23343671.
  7. Phillips SM, Hartman JW, Wilkinson SB. Dietary protein to support anabolism with resistance exercise in young men. J Am Coll Nutr. 2005 Apr;24(2):134S-139S. Review. PubMed PMID: 15798080.
  8. Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR. Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise.Med Sci Sports Exerc. 2004 Dec;36(12):2073-81. PubMed PMID: 15570142.
  9. Zemel MB, Thompson W, Milstead A, Morris K, Campbell P. Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults. Obes Res. 2004 Apr;12(4):582-90. PubMed PMID: 15090625.
  10. Milk Protein Ingredients." American Casein Company. N.p., n.d. Web. 21 Mar. 2013. <>.
  11. Tello, P. G.-., Camacho, F., Jurado, E., Páez, M. P. and Guadix, E. M. (1994), Enzymatic hydrolysis of whey proteins. II. Molecular-weight range. Biotechnol. Bioeng., 44: 529–532. doi: 10.1002/bit.26044041
  12. Pennings B, Boirie Y, Senden JM, Gijsen AP, Kuipers H, van Loon LJ. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. Am J Clin Nutr. 2011 May;93(5):997-1005. doi: 10.3945/ajcn.110.008102. Epub 2011 Mar 2. PubMed PMID: 21367943.
About The Author
Elliot is a raw powerlifter who enjoys researching the science behind how the human body works. He has a BS in Biochemistry.

41 Comments+ Post Comment

No Profile Pic
Posted Wed, 09/23/2015 - 03:49

My age is 17 year old I am use in which product

No Profile Pic
Posted Sat, 01/17/2015 - 06:37

how can be usefull Casein for runners ?

No Profile Pic
Posted Mon, 04/14/2014 - 05:55
Jason Lilley

Dried milk powder is 80 percent casein and 20 percent whey protein. Wouldn't mixing milk powder to milk provide the benefits of expensive sports whey and casein supliments ? ?

No Profile Pic
Posted Wed, 02/18/2015 - 06:35
Ranjit Singh

milk powder is a dried milk, it contain as much nutrient as milk in itself, but skimmed mik powder contain 35% protein with as low as 1% fat & 50% carbohydrates (lactose) & minerals, it is the protein part which (i.e- 35%) contain 80% casein & 20% whey , that is in every 100gm dried milk 35 gm is a protein of which 27gm is casein & 7gm is whey .if you acidify milk & boil to form cheese ,whey part is lost in liquid & casein become cogulate. there is another point mostly all carb (lactose) is free from casein & easy to digest.

No Profile Pic
Posted Sat, 07/20/2013 - 10:17

I have been going to gym only for a month. Please tell me if I should try using whey or casein as of yet

No Profile Pic
Posted Sat, 07/20/2013 - 10:16

I have been going to gym only for a month. Please tell me if I should try using whey or casein as of yet

No Profile Pic
Posted Tue, 07/09/2013 - 02:44

i drink mostly abt half a liter of milk every day i think i am taking casein protein indirectly!! hope that,s enough for an avg male!

No Profile Pic
Posted Tue, 07/02/2013 - 04:08

Lots of knowledge on this page I grab n I really thank for whole page it's really helpfull

No Profile Pic
Posted Fri, 05/31/2013 - 14:53
Charlie Ledger

Quick question i was just wondering, can i take whey protein in the morning and after a workout and then take some Casein before i go to bed. Just curious if that is okay to do ??

mnsjason's picture
Posted Mon, 06/03/2013 - 18:43

That's actually a very good plan, as whey digests quickly. It's perfect for a quick protein boost in the morning after an 7-8 hour fast, as well as post workout. Casein is slowly digested, so it's perfect for before bed.

No Profile Pic
Posted Wed, 10/23/2013 - 19:03
Anthony H

I'm a weight lifter. I go to gym 4days/week. I use whey protein before and after work out. is it ok if I usecasein be 4 work out and whey protein after work out and are there any side effect to use them every day?

No Profile Pic
Posted Wed, 05/22/2013 - 17:25

CASEIN protein triggers genes to form cancer ..check The China Study ...see what scientist has to say about Casein at minute 22:10

No Profile Pic
Posted Wed, 05/22/2013 - 17:19

Doesn't anyone know that the protein CASEIN found in animal milk "Turns on" Genes that triggers formation of cancer??

No Profile Pic
Posted Tue, 05/14/2013 - 13:08

hi elliot
soooooo i am a yoyo dieter ,,,,,i am a nanny now so i dont get much work out could i incorporate this protien in my diet if for example i decide to take them for a walk every other day? and would skipping help?.....plz talk about dosage etc.


No Profile Pic
Posted Sat, 05/18/2013 - 15:42

I cant offer specific advice about dosage without knowing other factors about you. What I can advise is that you incorporate casein protein in your diet at your discretion/convenience. The "time" you take it shouldn't be of primary concern for someone in your position. Also, if you want to skip, go for it

No Profile Pic
Posted Tue, 05/07/2013 - 13:35

Very informative article. Could you tell me at what age can an athletic begin to take casein?

Thank you.

No Profile Pic
Posted Sun, 05/12/2013 - 14:31

Thank you. There is no real restriction on what age to start using casein protein.

No Profile Pic
Posted Thu, 05/02/2013 - 16:23
Anand Rao

This is a well written article! There is so much misinformation on the web about caseins and whey proteins, it is refreshing to see a well balanced article with accurate, science-based information.

No Profile Pic
Posted Sun, 05/12/2013 - 14:29

Thank Anand, I'm glad you took the time to read it!

No Profile Pic
Posted Sun, 04/28/2013 - 11:44

Any suggestion for replacing casein for a vegan diet? My husband is hoping to adapt his lifestyle to mine, a plant base diet however is struggling with the protein replacement part of his exercise regiment, particularly the slow release protein such as casein. He has switched and enjoys the benefits of Vega Sport and Sun Warrior however from what we have read they are more so a viable solution to whey, perhaps a better understanding of the amino acid composition of once versus the other would provide us with the required information, thoughts?

No Profile Pic
Posted Tue, 04/30/2013 - 18:29

Hi San,

Well a vegan diet will unfortunately be limited in options to meet protein needs. I would say that his best options from a theoretical standpoint would be using a brown rice protein powder and/or pea plant protein. Soy protein and wheat protein are also feasible in moderate amounts, but definitely not something to subsist on.

No Profile Pic
Posted Thu, 04/11/2013 - 08:56

I really enjoyed your article. I have been trying to put on more lean mass and have seem to hit a plateau. I am going to try taking Casein before bed. Thanks.

No Profile Pic
Posted Tue, 04/02/2013 - 03:14

I like the article, just seems a bit one sided without a nutritionist point of view.

With the amount of re-search put into this, how about listing the cons (health risks) in consuming Casein. If you will, like the effect on the digestive system on how taking Casein blocks the absorption vitamins and minerals.

No Profile Pic
Posted Fri, 04/05/2013 - 16:02
Elliot Reimers

Hi AJ,

Thank you for the feedback. FWIW, "nutritionist" is a somewhat ambiguous term these days and I would be wary of people who consider themselves "expert nutritionists" just because of their certifications or credentials. But I digress...

I will amend in a pro/con section as I like that idea. On a quick note, I'm not aware of any studies that conclude casein causes malabsorption of nutrients in otherwise healthy subjects, in fact I've only seen the inverse occur in the literature whereby casein actually decreased intestinal permeability(1).


No Profile Pic
Posted Fri, 03/29/2013 - 13:44
Andrew S

Cottage cheese is a good source of casein protein isn't it? I try to eat it before bed on lifting days.

No Profile Pic
Posted Fri, 03/29/2013 - 16:48
Elliot Reimers

Hi Andrew,

Yes cottage cheese has a good amount of casein protein content, I too like to eat some before bed most nights.

No Profile Pic
Posted Thu, 03/28/2013 - 15:58

thanks for the article, i had a question though. Lately I have been hearing the best way to take both whey and casein proteins was by mixing them together. so everytime you take a scoop of whey you mix in casein with it. I have *heard* from others that studies have been done and proven this is the best method, is this true or bollox? thanks.

No Profile Pic
Posted Fri, 03/29/2013 - 17:03
Elliot Reimers

Actually quite a few studies have shown there is benefit to doing what you outlined here (and I referenced a few in this guide). If you follow the more traditional dogma of "nutrient timing" I would follow what I outlined above in the "when should I take casein" section since whey protein will be a bit more useful directly post-workout.

No Profile Pic
Posted Thu, 03/28/2013 - 14:27

Well-written and comprehensive. I know for myself, at least, that some sort of guide for assessing the quality of casein protein at a glance would be extremely helpful (i.e., what a calcium caseinate should look like compared to micellar casein, or a a high-quality micellar versus a lower-quality).

Perhaps in an edit? :D Otherwise, bang-up job here.

No Profile Pic
Posted Fri, 03/29/2013 - 17:05
Elliot Reimers

Hi Dustin,

Thanks for the feedback, I appreciate it!

I like your idea as well, I'll try and get around to amending that into this guide or possibly making a separate page for your reference.

No Profile Pic
Posted Thu, 03/28/2013 - 14:22

Well-written and comprehensive. I know for myself, at least, that some sort of guide for assessing the quality of casein protein at a glance would be extremely helpful (i.e., what a calcium caseinate should look like compared to micellar casein, or a a high-quality micellar versus a lower-quality).

Perhaps in an edit? :D Otherwise, bang-up job here.

No Profile Pic
Posted Thu, 03/28/2013 - 03:40

Casein is a terrible source of protein and literally feeds cancer cells. See: The China Study.

No Profile Pic
Posted Fri, 03/29/2013 - 16:58
Elliot Reimers

"The China Study"...Hmmm, interesting please do tell more.
Seems rather unfounded to make such a claim given that a distinguishing features of a cancer cell is its ability to proliferate in the absence of growth factors (i.e. proteins, hormones, etc).

No Profile Pic
Posted Mon, 09/02/2013 - 21:27
Michael the bio...

Yeah! the china study! problem is... the Chinese do not consume milk, cheese or any other dairy products (except when they are breast fed). I could think of why they are trying to protect their soy milk and tofu from casein competition. This was a joke... Now for some serious reasoning: this was a lab study, my friend. Do you know how often researchers discover cancer promotion or suppression in vitro that never translates into animal or human studies? Very often )) Trust me, I am a professional developer of pharmaceuticals. And the last argument... the Dutch and the Indians consume a lot of milk throughout their lives, but you don't hear them dying from cancer left and right do you?

No Profile Pic
Posted Wed, 05/22/2013 - 17:21

CASEIN protein turns on genes that triggers cells to mutate and become cancer.

No Profile Pic
Posted Wed, 03/27/2013 - 23:34

Great info, thanks!

No Profile Pic
Posted Fri, 03/29/2013 - 17:06
Elliot Reimers

Thank you for reading Craig!

No Profile Pic
Posted Wed, 03/27/2013 - 18:42

Thank you! Really helpful ;)

Another question that I have is, if we should count the milk's sugars (lactose) to our post-workout meal. i.e. In addition with other sugars, such as dextrose or banana carbonhydrates.
Thanks in advance!

No Profile Pic
Posted Wed, 03/27/2013 - 20:47

Thanks George, I appreciate you taking the time to read this.

As for your question, yes you would count the carbohydrates from milk as part of your post-workout carb intake. Hope that helps you!

No Profile Pic
Posted Thu, 03/28/2013 - 16:44

You helped me a lot!!
Thanks again!

Steven's picture
Posted Wed, 03/27/2013 - 17:45

Very well written Elliot.