Whey protein is typically considered to be the gold standard for protein powder. Other forms of protein could arguably be just as good, or similar, but it is hard to argue that another form of protein is “better” for muscle growth. But if you are relatively new to buying protein powder, you may have noticed that there are multiple types of whey protein. Whey protein concentrate (WPC) and whey protein isolate (WPI) are the most common types.
This leads to the obvious question: Which one should you buy? Which one is better? Are there certain situations where you would benefit more from one over the other?
These questions are what this post is designed to answer.
What is the Difference Between WPC and WPI?
Whey protein goes through a filtration process while in production. WPC is only filtered once, while WPI is filtered a second time.
Having a second filtration means that WPI has even more fat and carbohydrate removed.
A simplistic way of remembering it is that whey protein isolate is a more isolated form of protein, due to having more carbs and fat removed.
How Much Does this Difference Change the Nutrition?
Hearing that there is a removal of more carbs and fats makes it seem like WPI is significantly superior. As always though, it is worth being aware of the context.
WPC is already low in carbs and fats already. Check out the image below to see what this looks like.
As you can see, both are low in carbs and fats. Whey protein isolate is just lower. But per serve, we are talking about roughly a 1.5g reduction in carbs and fats respectively. There is also a small increase in protein.
It is worth being aware of this difference. But it is also not really a big deal.
Lactose
Something that matters a little bit more is the lactose content.
WPC is higher in lactose than WPI is.
Context is needed once again though.
The average person with lactose intolerance can often tolerate at least 3g of lactose with zero symptoms. Most can have more.
A cup of milk has ~12g of lactose in most cases.
Lactose is a type of sugar. We can see that the WPC featured above has 1.7g of sugar per serve, meaning it has a maximum of 1.7g of lactose.
Most people with lactose intolerance do not need to worry about this. But for those who are more sensitive to lactose than others, the difference does matter.
It matters far more for people who are double scooping the protein powder or mixing it with other lactose-containing foods too.
In the cases where it matters, it makes sense to use WPI instead of WPC.
Price
Since WPI goes through the filtration process twice, it is more expensive to make. This means it also costs more to buy.
As you can see in the image earlier comparing the price of the two versions from Bulk Nutrients, it is often around a 20% increase in price.
It is not a huge increase. But if both products are relatively equal, it would make sense to go with the more affordable option.
Which Should You Choose?
Personally, I recommend WPC to almost all people who do not notice any issues related to lactose intolerance. For those people, I recommend WPC.
The difference in the rest of the nutritional profile is relatively insignificant.
If somebody had so much money and finances did not really factor in, then I would consider going with WPI if that was their preference.
Both options are great options. In most cases, there is no right or wrong.
Hopefully, this summary clarifies things and makes it easier to feel confident in your decision though.
