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Optimum Nutrition 100% Casein 4 Lbs

24 reviews   |  
Original price $103.49
Original price $103.49 - Original price $103.49
Original price $103.49
Current price $99.99
$99.99 - $99.99
Current price $99.99
SKU 748927024227
Most USA Orders Ship Free Over $99
Excludes drinks, liquids, bars, and foods.
flavor: Chocolate Supreme

Optimum Nutrition 100% Casein 4 Lbs | Slow Digesting Protein Supports Muscle Recovery

Casein Protein is a slow digesting protein which contains all the amino acids necessary to help you build muscle, as well as support muscle recovery. This is a great protein to take prior to bedtime to support muscle recovery as well as helping to reduce appetite and increase feelings of fullness making it a great option for a meal replacement. Optimum Nutrition Casein Protein features 24 grams of slow digesting protein, packed with amino acids and with only a single gram of sugar. 

Optimum Nutrition 100% Casein Highlights & Benefits

  • 24 Grams Casein Protein
  • Slow Digesting Protein Great For Overnight Recovery
  • Helps Build and Maintain Muscle
  • Naturally Occuring BCAAs to Support Endurance and Muscle Recovery
  • Great For Between Meals or Before Bedtime
  • Only 1 Gram of Sugar

Casein Protein Vs. Whey Protein

Casein and whey proteins are both derived from milk however casein is a slower digesting protein making it a great nighttime protein where as whey protein digests quickly and is ideal to drink just after a workout. 

When Should I Drink Casein Protein?

Casein Protein can be taken anytime of day, it's especially satiating making it great between meals or as a meal replacement, however the most popular time to take casein protein is just prior to bedtime. 


Mix 1 scoop with 10-12 ounces of cold water, milk, or beverage of your choice. 

Optimum Nutrition 100% Casein 4 Lbs Ingredients & Label

Optimum Nutrition 100% Gold Standard Casein Ingredients

Warnings & Side Effects

Store in a cool dry place after opening. 


Antonio J, Ellerbroek A, Peacock C, Silver T. Casein Protein Supplementation in Trained Men and Women: Morning versus Evening. Int J Exerc Sci. 2017 May 1;10(3):479-486. PMID: 28515842; PMCID: PMC5421981.

Trommelen J, Weijzen MEG, van Kranenburg J, Ganzevles RA, Beelen M, Verdijk LB, van Loon LJC. Casein Protein Processing Strongly Modulates Post-Prandial Plasma Amino Acid Responses In Vivo in Humans. Nutrients. 2020 Jul 31;12(8):2299. doi: 10.3390/nu12082299. PMID: 32751788; PMCID: PMC7468913.

Customer Reviews
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Dennis E.
United States United States

Awesome Casein!

This is the best casein. Mixing isn't always the best.


Add this to your whey regimen

Tried using this protein mix in addition to my 100% whey by Optimum Nutrition. This is a great alternative when looking for a slower digesting protein- i particularly take it as my night time shake before bed, and occasionally int he morning (and use my whey right after the workout). I do find that this does not quite mix as well as the whey, and the taste and drinkablility isn't as good. Overall a good option if you require a casein. Like the whey the bcaa's and glutamine are a great addex extra.


Great Product

Received a sample of this product, chocolate flavor, product mixed well and tasted good would definitely buy this product


Banana is a little weak

The banana flavour of ON Gold Casein is quite weak. I mix it with minimal water, and even then it was way too weak for me. When you open the container it smells amazing, just like banana milk that we have in Australia (so more a 'candy' banana than a real one), but the flavouring is really subtle. Shame really, as I was really looking forward to this one. Great product, so go with another flavour is my suggestion.


hard to get used to, overall good

Ok, let me start this off by saying that if you do not use enough liquid to mix, it will become think like pudding, it has a gritty consistency, I mix mine with low fat milk for the flavor. Add cinnamon, and it makes it tolerable until you get used to the texture. I put on a good amount of weight, and was using this for muscle building, taking it right before bed. OVER ALL I WOULD RECOMMEND, BUT DEF. TAKES SOME GETTING USED TO.


Great taste, decent value

I have used ON Casein for a few years now and this flavor is the best tasting and best mixing in my opinion. It has a nice creamy taste and mixes excellent because of the little cookie crunches in it. I wish the pricing was a little cheaper but still a great product overall


Best flavored protein powders on the market.

I purchase ON Casein while on a quest for a slow-digesting protein source before bed. Having previously trying the Gold Standard whey, i gave it a shot. I rank it very high on the scale of tasteful protein powders currently on the market. With the consistency being rather thick due to the nature of casein protein, i found it very palatable and satiating. An amazing caveat of this protein is I no longer twist and turn in the bed from a partially digested chicken breast while trying to fulfill my protein need for the day. All in all a great product to add to the muscle building arsenal.


Awesome flavour - treat on a cut

I was given a sample of the Vanilla flavour of this to try and it is great! I'm quite a fan of protein powders, but I don't like having them as a shake. I like Micellar Casein because it can be made into a nice little pudding. This one tasted GREAT! I just add a little bit of water (maybe equal water to powder) and shake it up to a nice thick pudding. ON gives a great consistency and flavour. I seriously recommend it.


Quality Product That Doesn't Disappoint

The wife and I bought this to get meat back on my bones and less off of hers. We drink a serving every night right before bed and know we're doing the right thing for our bodies. Quality = It's Optimum Nutrition, nothing left to say Mixability = Smooooooth :) Flavor = nom nom!! :) Texture = You'd almost swear you're drinking a chocolate shake for the local soda ****! You won't be disappointed!


Solid product

ON is a solid brand with solid nutritional information. The chocolate is a safe bet and tastes pretty decent. Mixes a tad chunky but its 100% casein so you're getting exactly what you paid for.


Cookies & Cream

Optimum Casein is great stuff but it can be very hit and miss. Cookies & Cream doesn't really taste like Cookies, nor of Cream. Instead it is just a 'not' protein. It is 'not' Chocolate. It can be stomached, perhaps even enjoyed (though not by me), but it is not Cookies and Cream. I won't be buying this one again.


Chocolate Cake Batter

My favourite flavour of this is definitely chocolate cake batter. Three ways of having it depending on macros. 1) Mix 1.5 scoops of water per 1 scoop of casein 2) Mix 1.5 scoops of cream per 1 scoop of casein 3) mix 1.5 scoops of milk per 1 scoop of casein Add in nuts, or top with whipped cream and this makes an AWESOME dessert. Try this, especially if you love your ice cream or your pudding and you will NOT be sorry. HIGHLY recommended!


Above Average

Overall, this is an above average protein. There are obviously a ton of different proteins out there, so I would suggest trying a few different ones. This one obviously has good casein protein. I would recommend taking it right before bed or for a meal replacement. I took it right before bed and I didn't wake up as hungry. Also, it's a good price and good taste.



Overall, this is an average casein protein. It's casein, so I usually used it right before bed or for a meal replacement. It is also good mixed it with smoothies, pancakes, pudding, etc. It is thicker than most proteins, and I think that makes it taste better. I would suggest the chocolate flavor. There are better proteins out there, but this isn't bad.


Decent protein

Overall, it's a decent protein. It's thicker than whey, so it's more filling. Taste wise, it's about average. Could do better.


Solid Product for Recovery and Muscle Building

I have taken this casein for a couple of years now and it is a staple in my diet. It allows me to pack on lean muscle as it allows me to reach my protein needs and helps with recovery. I also like how it gives me a full feeling before bedtime which makes it easier for me to resist late night snack temptations. If you are looking to pack on a few pounds of muscle, give ON 100% Casein a try.


Hands down the highest quality casein available...

If you want 100% micellar casein, this is pretty much the only product I would recommend. The product turns to pudding incredibly easily due to it being pretty much nothing but 100% micellar casein. I've made the mistake of throwing in a scoop of fiber with 2 scoops of the protein into a regular shaker cup, it simply turns into thick pudding instantly. The good news is that this is a clear indication that all you have here is high quality 100% micellar casein, the bad news is that the stuff is hard to mix especially in a regular shaker cup. With 1 scoop, it's ok to mix in a 27 ounce shaker with about 12 ounces of water. With 2 scoops, it's just not really going to mix all that well, it turns too thick and even in 24+ ounces of water, in a shaker cup the stuff just turns too dense for the shaker cup to be able to do it's job. I do highly recommend this product though as it's no nonsense and you get exactly what you paid for.


ON Casein needs to be in your diet

Optimum Nutrition Casein is top notch ! It mixes well and tastes great. My favorite flavor is the chocolate cake batter but I figured I would give the banana cream a try. I am pleased with the taste, and even started mixing it with some of the choc cake batter I had left over to make my own flavor....choc covered banana flavor. My fitness goals are to put on lean muscle mass and this product along with ON Whey are very effective. I take the casein just before bedtime and the whey after workouts. Casein is an important part of my diet and if your goal is to put on lean muscle mass, it should be part of your too

John K.

Good Casein

Good product for pre-bed time and sleep recovery. Casein is very slow digesting, and this one tastes great. Just keep in mind its thicker in texture then whey protein.


Fantastic Product

Optimum Nutrition Casein is a fantastic product, mixes easily in a shaker and tastes much better than other Casein powders I've had. ON Casein is also a lot less "goopy" when mixed with the indicated amount of water, so it is much easier to drink than others, such as those branded by a well-known supplement retail chain whose name is a 3 letter acronym.