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Optimum Nutrition

Optimum Nutrition 100% Casein 4 Lbs

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Optimum Nutrition 100% Casein Protein 4 Pounds

On Gold Standard Casein 55 Servings

Casein proteins are a very unique form of protein, casein is ph sensitive and when they come into contact with the acidic environment of the gut they turn into a gel. This gel takes a nearly twice as long to digest as other forms of protein. If you are looking for a high quality casein protein that will feed your muscles and keep amino acid levels high for up to 8 hours.


  • 24 grams of Slow Digesting Casein Proteins
  • Micellar Casein Rich
  • 9 grams of BCAAs, Glutamine,
  • 3-4g of Carbs
  • 55 Servings

Optimum Nutrition Casein Reviews


Optimum Nutrition Casein a great product! I had the blueberry flavor very good! Casein is a great product to take rite before bed time im a big fan of this.


I use for a nighttime snack before bed and it really helps to curb my appetite. Mix-ability was fine with a blender and the taste was great!



Serving Size: 1 Heaping Scoop (34 g)
Servings per Container: 53
Amount Per Serving % Daily Value
Calories 120
Calories from Fat 10
Total Fat 1 g 2%
Saturated Fat 0.5 g 3%
Cholesterol 14 mg 4%
Sodium 280 mg 12%
Total Carbohydrates 3 g 1%
Dietary Fiber 1 g 4%
Sugars 1 g
Protein 24 g 48%
Vitamin A 0%
Vitamin C 0%
Calcium 50%
Iron 4%
Other Ingredients: Micellar Casein, Cocoa (Processed with Alkali), Natural and Artificial Flavors, Salt, Gum Blend (Cellulose Gum, Xanthan Gum, Carrageenan), Lecithin, Acesulfame Potassium, Sucralose, Aminogen®.


Take one to two scoops before bed or when a sustained release protein is required.


Side Effects


Customer Reviews
4.6 Based on 24 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.

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