Optimum Nutrition Casein Review: An Inexpensive Protein Solution!

If you're using a protein supplement as part of a meal replacement shake or before bed, casein protein may be more appropriate. Learn more about Optimum Nutrition's Casein Protein now.

Protein supplements are probably the most widely researched, criticized, and utilized dietary/performance aids in the world. The scientists generally imply that supplemental protein isn't beneficial to performance, and that sufficient protein can be consumed in the diet to meet the body's needs. I always laugh when I hear statements like that. The same is often said about the lack of necessity for taking a multivitamin.

They may be right. A proper well-planned diet may be all we need, but I don't know a single person that consistently eats a "text-book" diet.

The truth is that most people are constantly on the go, and simply don't have the resources (e.g. time and money) to eat the way they should. As a result, many people lean on supplements to keep them going. With the positive benefits of high protein diets on body composition and muscle maintenance/growth, protein supplements receive a justifiably large amount of attention.

While this is an oversimplification, protein supplements are basically broken down into:

Whey protein is more rapidly absorbed than casein protein, which essentially has a time-release effect. Is one better than the other? It probably depends on what you're using them for.

If you need high quality protein right away (e.g. immediately before/during/after a training session), whey may be a better choice.

If you're using a protein supplement as part of a meal replacement shake or before bed, casein protein may be more appropriate. Optimum Nutrition's 100% Whey Protein is the top seller on Bodybuilding.com. I thought I'd give ON's Casein a try and see how it fared.

If you're using a protein supplement as part of a meal replacement shake or before bed, casein protein may be more appropriate than Whey.
"If you're using a protein supplement as part of a meal replacement shake or before bed, casein protein may be more appropriate than Whey."

Nutrition Facts

Supplement Facts
  • Serving Size: 33 g
  • Servings Per Container: 54
  • Calories: 120
  • Fat Calories: 10
  • Total Fat(g): 1
  • Saturated Fat(g): 0.5
  • Cholesterol(mg): 10
  • Total Carbohydrate(g): 4
  • Sugar(g): 1
  • Protein(g): 24
  • Calcium(daily value): 50%
  • Iron(daily value): 4%
Essential Amino Acids
  • Tryptophan(mg): 292
  • Valine(mg): 1609
  • Threonine(mg): 1039
  • Isoleucine(mg): 1312
  • Leucine(mg): 2129
  • Lysine(mg): 1822
  • Phenylalanine(mg): 1144
  • Methionine(mg): 644
Conditionally Essential Amino Acids
  • Arginine(mg): 866
  • Cystine(mg): 79
  • Tyrosine(mg): 846
  • Histidine(mg): 688
  • Proline(mg): 2421
  • Glutamine & Precursors(mg): 4950
Nonessential Amino Acids
  • Aspartic Acid(mg): 1589
  • Serine(mg): 1396
  • Glycine(mg): 510
  • Alanine(mg): 664
Ingredient Details

Protein Blend (Micellar Casein,, Calcium Caseinate), Cocoa(Processed With Alkali), Natural And Artificial Flavors, Salt, Lecithin, Gum Blend (Cellulose Gum, Xanthan Gum, Carrageenan), Sucralose, Aminogen®.

Allergen Information

Contains milk and soy (lecithin) ingredients.

Suggested Use

Consume first thing in the morning, before bed, to replace small meals, and/or any other time when delayed protein absorption is desired.


These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.


Great! This is one of those supplements that I found myself electing to have a protein shake/ON Casein Protein-based smoothie instead of a meal, just because I liked the taste (read below).


Mixes easily with water. I also mixed it in with yogurt or cottage cheese. I may be crazy, but I thought it tasted like chocolate cheesecake when I mixed it with one of these dairy products. It's a little grainy, as you can imagine, but still tasted great. If you're a fat kid at heart like I am, throw some peanut butter and nuts in there and make yourself a Reese's flavored snack/meal replacement.


It's pretty difficult to say whether a protein supplement was "effective" or not, as they don't have a profound effect like some other supplements do. I consider a protein supplement effective if it tastes good, I continue to make training progress, and I continue to feel like I'm recovering adequately from my training. With those things in mind, ON's 100% Casein Protein did the trick.

Overall Review

ON's 100% Casein Protein is one of the most reasonably priced casein protein supplements on the market. If you're an avid fan of their whey protein, it's worth giving this one a shot.

I'll end on a pleasant note: from time to time you may find that consuming a protein supplement will initiate the escape of foul and unpleasant odors from one of your body's orifices. If you ever suffer from this affliction, try taking another brand and/or form of protein.

Even if you're happy with the results of a particular brand/form of protein, it's probably best to rotate your supplements (just as its important to have a wide variety of foods in your diet) to keep your body from adjusting to one form of protein.

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