However, you’ll rarely encounter a protein powder that is solely milk protein powder. More often than not, it’s included as part of the blend in various powders and will be listed as “milk protein concentrate”, or preferably, “milk protein isolate”. The milk protein isolate version will have the lactose removed from the powder (similar to how whey protein isolate is below).

The benefits to consuming milk protein powder is that it already has the advantage of being blend since it contains both forms of proteins, and gets the benefits of both This not only helps provide a better texture for the powder when mixed in liquid or yogurt (as the casein part is much thicker), but also gives it a sustained release in the body thanks to the casein as well.

Milk protein actually contains two different types of protein, whey and casein . Milk typically contains 80% casein protein and 20% whey protein. [19]

Whey Protein

Whey protein accounts for 20% of milk protein and is the most common and widely purchased type of protein on the market. Part of the reason is that it’s an incredibly affordable source of protein. The other, and more important, reason is that whey protein provides the full spectrum of all 9 essential amino acids required for building muscle and is rapidly absorbed by the body.[20]

Furthermore, it boasts one of this highest biological values (BV) of any type of protein a human could consume. Regular milk protein has a BV of 91, very respectable, and egg protein has a score of 100 (making it the “ideal” source of protein). However, when reviewing whey protein on its own isolated from milk, whey protein powder has a BV of 104![21]

Basically, there isn’t a more bioavailable and readily absorbed protein by the body than whey protein. If you’re physically active and trying to build muscle, you need and WANT this protein.

But not all whey is the same. There are several grades of it available, and it may make a world of difference to you:

Whey Protein Concentrate (WPC)

It would be easy if there was only type or class of whey protein to purchase, but like most things in life, it’s a tad more complicated. While you can just purchase a plain whey protein powder, if you look at the ingredients panel, it may list a few different kinds of whey protein.

Put simply, whey protein concentrate is the lower-quality form, but even that depends on the grade of whey concentrate used.

Whey protein concentrates (WPC) can range anywhere from 35-80% protein, with the remaining percentages composed of carbs (from lactose) and fats.[22]

Typically we like to see companies list the quality of their whey concentrates (such as PES Select Protein, which lists WPC-80 and is discussed in various places on this page. This shows you’re getting the highest quality whey protein concentrate with less carbs and fats to take away from all the protein gains!

With all that said, whey concentrate is usually thicker and better-tasting than pure isolates, discussed next.

Doesn’t specify the exact type of concentrate? Then buyer beware

As a general rule of thumb, if you’re getting whey protein concentrate, but the label doesn’t tell you what kind of whey protein concentrate, then there’s a very high chance you’re getting the cheap stuff – likely 35-55% protein. What’s in the other 45-65%? Anything from milk sugars (lactose) and other carbs to fats to impurities like ash or extra moisture.

So the main drawback to WPC is that users who don’t tend to digest dairy all that well experience some GI upset or bloating from concentrates due to the higher lactose content. Don’t worry though, if you’re one of these unfortunate souls, there are still other whey options for you to come.

Whey Protein Isolate (WPI)

Whey Protein Isolates are a more “refined” source of whey protein, and a considerable step up in terms of protein content and digestibility. WPI have been processed to remove all carbs (lactose) and fats from the concentrate powder, as such, they must contain at least 90% protein. [22]

Compared to casein, isolates have been shown to significantly improve strength gain over its slower digesting counterpart.[23]

Put simply, if you are lactose-sensitive or lactose intolerant, the only whey protein you should ever touch is a whey protein isolate.

Those who are only lactose sensitive, but not completely full-blown lactose intolerant, could most likely get away with a product that has whey protein isolate as the first ingredient on the label (potentially followed by whey concentrate, milk protein concentrate, or casein protein after that).

Whey Protein Hydrolysate (Hydrolyzed Whey Protein)

Hydrolysates represent the final “refinement” of whey proteins. Here, whey protein has basically been “predigested” or hydrolyzed. Basically, this takes the already rapid digestion rate of regular whey and cranks it up to 11.

The thinking behind using hydrolyzed whey is that the ultra-fast digestion would further improve muscle protein synthesis since it would flood the bloodstream with tons of essential amino acids faster than whey or casein, but looking at two studies that each compared whey and hydrolyzed whey to casein, the differences are negligible at best.[24,25]

Furthermore, since even more processing is needed to create hydrolyzed whey, it also means it’s the most expensive of the whey options available. So, unless you absolutely can’t tolerate whey concentrates or isolates then go for hydrolysates, but by this point it may be cheaper to invest in one of the alternate forms of protein powder.

The honest truth is that most athletes don’t need to worry about getting such super-fast digestion. There isn’t that much of a race to make this type of protein worthwhile. And to add to the extra cost, hydrolyzed whey typically tastes a lot worse and is tough to flavor.

So who should look at hydrolyzed whey protein?

Those who have severe digestive issues or absorption issues will do well to look at whey protein hydrolysates. Anecdotally, this works far better for patients with diseases such as AIDS or certain forms of cancer, but if you have such an ailment, you should talk to your doctor about the best way of getting a boost of protein.