Whey concentrate and whey isolate: what is the difference?

Whey protein powders are usually sold as concentrate, isolate or a blend of the two. The difference comes from how the whey is filtered.

Whey concentrate goes through less filtering. It keeps more of the milk's natural fat and carbohydrate (including lactose), and typically contains around 70–80% protein by weight.

Whey isolate is filtered further, which removes more fat and lactose. It typically contains 85–90% protein by weight, and usually costs more per kilogram.

When comparing products, look at the protein per serving, the serving size and the price per serving rather than the tub price alone.