Whey Isolate vs Concentrate: which one wins for cutting?

Both whey concentrate (WPC) and whey isolate (WPI) come from the same place — milk — but the filtration is what changes the macros and the price tag on the shelf.

Concentrate sits around 70–80% protein by weight with some lactose and a little more fat. Isolate is filtered further, lands at 90%+ protein, almost zero lactose, and virtually no fat. If you're lactose sensitive or chasing a tight cut, isolate earns its premium. For everyone else? Concentrate gives you more protein per pound spent.

Our pick: WPC for bulking and budget-conscious lifters, WPI for cutting phases and anyone with mild lactose intolerance.