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Optimum Nutrition Gold Standard 100% Casein Protein

Optimum Nutrition Gold Standard 100 Casein

Where to Buy Gold Standard 100% Casein

ON Gold Standard 100% Casein Overview

If you are already using a whey protein isolate product for your post-workout needs then you might like to consider checking Optimum Nutrition Gold Standard 100% Casein as it provides a more slowly-digesting protein that helps to fill the gaps between meals and while you sleep at night.

If you’ve ever heard the phrase ‘curds and whey’ then you probably know that this refers to the main proteins that are found in milk – casein and whey. Whey only makes up 20% of milk, the other 80% is made up of casein. So you can see that it’s a pretty powerful nutrient.

Whey is a relatively fast-digesting protein while casein, on the other hand, forms a gel in the gut, providing a kind of trickle effect that gives you a more released sustain of amino acids into your bloodstream. The fact that casein is slow digesting means that you can depend on it to keep you going through bouts of fasting. It’ll help your body stay nourished if you can’t get to food for a lengthened period of time. That’s why it’s usually recommended to take before going to sleep since you’re body is in an 8-10hr long state of not eating.

Gold Standard 100% Casein Ingredients

Micellar casein constitutes the primary ingredient in Gold Standard 100% Casein but in the interest of thoroughness let’s take a closer look at exactly what is on the ingredients list:

  • Micellar Casein
  • Natural and Artificial Flavors
  • Polydextrose
  • Gum Blend; containing
    • Cellulose Gum;
    • Carrageenan; and
    • Xanthan Gum
  • Citric Acid
  • Lecithin
  • Malic Acid
  • Beet Powder
  • Acesulfame K
  • Sucralose
  • Aminogen

Optimum Nutrition Gold Standard 100 Casein nutrition label facts

How and When Do I Take It?

As per the manufacturer’s directions, you are to add one scoop of Gold Standard 100% Casein to 10 – 12 oz of water or milk, and then shake vigorously until thoroughly mixed. Using a blender or a shaker cup is all you’ll need, it’s pretty simple. You can even add in fruit or peanut butter in a blender to make a tasty shake.

You can, of course, vary the amount of Gold Standard 100% Casein and water you use depending on your desired consistency and your protein requirements.

This product is best used between meals, as a meal replacement, or before bed. There is a simple and obvious reason as to why you should consider taking it before bed. Casein is slow digesting, and when you sleep your body is going to not be taking in nutrients for about 8-10hrs, so taking casein allows your body to slowly absorb it while you sleep.

Benefits of Gold Standard 100% Casein

When you drink a whey protein concentrate or isolate shake you will typically elicit a sharp rise or ‘spike’ in your blood amino acid levels.

Whey protein isolate is particularly useful for the post-workout period when we want this sharp rise in blood aminos, and hydrolyzed whey isolates are released so rapidly into the bloodstream that they are often used intra-workout.

Casein covers the opposite end of this spectrum by digesting very slowly.

For those of us that sleep eight or more hours a night, our body’s are essentially being starved of nutrients during this period, so drinking a casein shake before going to bed can help to provide a sustained release of amino acids in your body so that you are basically being fed while you sleep!

What’s more, the slow-digesting nature of casein makes it ideal for use between meals or as a meal replacement shake when you are dieting and want something that is going to fill you up for a reasonable amount of time.

Add a cup of oats and / or a tablespoon of peanut butter and the added fiber and fat will help to slow down digestion, even more, keeping you fuller for longer!

Are There Any Precautions?

Seeing as this is a fairly basic protein powder there aren’t really any major precautions you need to take.

If you suffer from a milk allergy then you will definitely want to exercise caution when trying Gold Standard 100% Casein for the first time because casein is typically the main allergen in milk besides lactose.

You should also ensure you are using this as a supplement and not your sole or primary source of protein in your diet.

Please note: The exact flavorings used in your protein powder will be largely dependent upon the flavor you choose.

Available Flavors and Serving Sizes

Optimum Nutrition Gold Standard 100% Casein is available in the following flavors:

  • Banana Cream
  • Blueberries & Cream
  • Chocolate Cake Batter
  • Chocolate Peanut Butter
  • Chocolate Supreme
  • Cookies & Cream
  • Creamy Vanilla
  • Mint Chocolate Chip
  • Raspberry Smoothie
  • Strawberry Cream

You’ll also find it available in the following serving sizes:

  • 2lbs
  • 4lbs


Having used Optimum Nutrition Gold Standard 100% Casein for quite some time I can definitely attest to the quality of this product. It doesn’t promise anything it can’t deliver on. I usually take both whey and casein, but that’s not really necessary unless you are training for something or really want to make serious gains and quick.

If you’ve ever compared the satiety effects of whey and casein then you’re probably well aware of how much longer it keeps you full for, but if this is your first time trying a casein product then you can rest assured that it will definitely satisfy your hunger. There is no “better” option between whey and casein. They both have their uses and benefits as mentioned above.


Don’t expect miracles from this product; you’re not going to feel full for six hours if you drink a shake! As with any supplement on the market, you’re using it as a boost to your nutrition, not as your nutrition itself. Always keep in mind that there are natural sources of all supplements, and in casein’s case any dairy products will provide you with a dose.

Having said that, mixing Gold Standard 100% Casein with a healthy fat source and some fibrous carbohydrates like oatmeal might keep you fuller for longer than a standard meal of chicken and veggies.

This is especially feasible if you add a lot of extra water to your shake.

Mixing it with milk is going to give you even higher benefits considering the milk itself will provide you another huge dose of casein mixed with the powder itself. Plus it tastes a bit better with milk.


The texture of casein is actually one of my favorite things about it, and although I’m not usually a fan of vanilla-flavored protein powders I absolutely love the vanilla variation of Gold Standard 100% Casein because of its texture. ON Gold Standard products are some of the tastiest on the market. You can bet that the casein protein is no different. You can mix it with milk or water and it’ll still taste delicious.

You can expect a slightly grainier that you would experience with a whey protein isolate product, but I personally think that this makes it all the more delicious.

Is it Worth the Money?

I definitely think that Gold Standard 100% Casein is worth the money because Optimum Nutrition makes some world-class products and don’t inflate their prices nearly as much as some of the other leading manufacturers on the market.

This is definitely one of the best casein protein powders you’re going to find so if you’re looking for a shake that will keep you fuller for a little longer than your regular old whey protein shakes then I would definitely recommend trying out some Gold Standard 100% Casein.

Final Thoughts

Although Optimum Nutrition Gold Standard 100% Casein isn’t particularly suitable for intra-workout and post-workout applications, it is overall my favorite protein powder in terms of taste, texture, and general day-to-day use.

The texture is due in part to the addition of the Gum Blend that Optimum Nutrition has thrown into the mix, so you are going to find some artificial flavors in this product.

Even so, Gold Standard 100% Casein is a great protein powder that offers solid value for money, high-quality proteins, and a range of flavors that are truly out of this world.

Whether as a flavorsome protein source mixed into your oatmeal, a tasty protein brownie, or just a standalone shake, Optimum Nutrition Gold Standard 100% Casein is a definite winner in my books, and one that I think should be on the supplement shelf of every aspiring bodybuilder.

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