Whey protein is protein that is isolated from whey, a by-product of cheese manufactured from cow’s milk. Whey protein typically comes in three major forms: concentrate, isolate and hydrolysate.
Concentrates contain a low level of fat and cholesterol but generally have higher levels of bioactive compounds, and carbohydrates in the form of lactose they are 29%-89% protein by weight.
Isolates are processed to remove the fat, and lactose, yet are usually lower in bioactive compounds as well they are 90%+ protein by weight.
Hydrolysates are predigested, partially hydrolyzed whey proteins which consequently are more easily absorbed, but their cost is generally higher.
Whey protein has the highest bioavailability of any protein known to man. It is commonly used immediately post workout.
Whey protein is the best-selling protein supplement in the world.