Before we discover the difference between WPI and WPC, let’s go over the basics of protein. Protein is perhaps the most important supplement for gym-goers, bodybuilders, and everyday people looking to have more control over their diet. Just like Iron Man needs his suit, or Michael Phelps needs a pool, protein is a necessity for individuals looking to get fitter, healthier, or stronger.

However, the term “protein” encompasses a variety of different forms. Sports protein usually consists of Whey Protein, which is found mainly in two forms – whey protein concentrate (WPC) or whey protein isolate (WPI). Before we delve into the differences between the two, let’s examine what exactly whey protein is, and where it comes from.

What is Whey Protein?

Put simply, whey protein is a powdered by-product of milk and cheese-making. That’s right, you see all those bottles of milk and blocks of cheese in the supermarket? Whey protein is left over from their production, after the process of separating the whey from the milk.

This process is relatively simple. Fresh milk arrives at a processing plant, where it is initially pasteurized to make it safe for consumption. Enzymes are then added to the milk, forcing the milk into two layers – a thick, solid bottom layer used to make dairy products such as cheese, and a liquid whey protein top layer. This top layer is pure whey protein, which is then sent off to a protein processing plant. These manufacturing plants firstly filter the pure whey protein to isolate the protein, dry the protein into a powdered form, add flavouring and additives, then package and sell to customers seeking protein supplements.

So, now that we know what whey protein is, what is the difference between whey protein concentrate (WPC) and whey protein isolate (WPI)?

difference between wpc and wpi graphic table

The difference between WPC and WPI


There are quite a few differences between the two most common forms of whey protein. However, the biggest difference can be found during the manufacturing process. During the initial filtering process, the whey protein is transformed into whey protein concentrate (or WPC). To create whey protein isolate (or WPI), this WPC is then filtered a second time to further refine and separate the protein. This process removes more carbohydrates, fats, and sugars from the whey – resulting in a purer protein powder.


Due to it’s increased refinement, WPI has a higher protein, lower fat, and lower carbohydrate percentage compared to WPC. Good quality WPI is generally around 90% protein by weight, compared to 75-80% for WPC.

WPC also contains more milk fat than WPI – resulting from it’s lack of double-filtration. This is not necessarily a bad thing, as this fat can contain beneficial elements and nutrients not commonly found in WPI (WPC contains around 4-7% milk fat).

Due to the less stringent filtration process, WPC tends to contain around 5% lactose. Oligosaccharides are found in this lactose, and act as helpful growth and immune regulatory factors, anti-microbial peptides, and prebiotics1.


Due to the fact that WPI is more refined and goes through a secondary filtration process, the body can digest and absorb it faster than WPC. This is because WPC contains more of the harder to digest components like fat and carbohydrates. Based on anecdotal evidence, individuals have found that WPI can potentially be digested and absorbed by the body faster than WPC.

Which should you choose?

Choose WPC if you’re after a cheaper, slower-digesting protein that contains lots of macronutrients and bioactive compounds. WPC is a great option to consume throughout the day.

Choose WPI if you’re after protein with lower levels of fat, carbohydrate, and lactose that contains less calories than WPC. WPI is ideal for people who want to get fast digesting protein into their body after a workout, or want to restrict the number of calories they consume. Additionally, those sensitive to dairy or lactose may benefit from choosing WPI over WPC due to the increased protein weight percentage over other compounds.


So there you have it – the differences between whey protein concentrate and whey protein isolate. As you can see, both forms of whey protein have their strengths and weaknesses, and you may find each of them helpful in different areas. It can be very useful to utilise a combination of each type of protein to assist you in completing your goals.


WPI or WPC - VPA Australia

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