Lactose is the sugar that naturally occurs in milk. An 8-ounce glass contains 9-14 grams of lactose2, which shows up on the nutrition label in the form of carbs.
But most of the carbs and lactose are removed during the process of making whey protein. That means whey concentrate has about 3 grams of lactose while whey isolate has <1 gram.
If you’re wondering how much lactose you can tolerate, researchers found that most lactose-intolerant people can handle up to 12 grams in one sitting or 24 grams over the course of the day3.
Therefore, most people should have no lactose reaction to either whey isolate or whey concentrate. Especially if you combine it with other foods.
When looking for protein supplements the first thing you’ll notice is that whey isolate generally has a higher price tag. This is due to the added processing costs.
However, the higher protein content of whey isolate means you actually get more protein for that price. So on average, the cost per gram of protein is about the same!