Ingredient · Protein
Whey Protein Isolate
The protein fraction of milk, filtered to remove most of the lactose and fat. A complete protein with the full amino acid profile, and the isolate grade is usually tolerated by people who react to whey concentrate.
also known as WPI
Whey is what separates from the curds during cheesemaking. Turning it into an isolate means filtering it — typically by microfiltration or ion exchange — until it is roughly 90% protein by weight.
The distinction worth reading for is isolate versus concentrate. Concentrate is cheaper and retains more lactose and fat; isolate costs more and is what appears in products aimed at people avoiding lactose.
Why it’s classified this way
Classified Safe: filtration only, and a complete protein source.
References
- USDA FoodData Central — Whey protein isolate