This mixture of globular proteins isolated from whey, or the liquid byproduct of cheesemaking from most milks. Commonly marketed as a dietary supplement, whey protein advocates have made various health claims as to its benefits for muscle growth and bodybuilding. Some people are allergic to whey proteins in milk, but the primary allergens in milk come from casein proteins. Extraction of protein from whey is accomplished by removing the fat and dehydrating the whey until it is in a powdered form. Sometimes lipids and other non-protein materials are further removed via spray drying after a membrane filtration separates the proteins from the whey. Whey protein typically contains higher concentrations of the amino acid cysteine, a cellular antioxidant has shown some evidence to be effective in reducing the risk of cancer in animals. Whey protein typically comes in concentrate and isolate form, with isolates being the leaner of the two sources of protein since it undergoes a process to remove bioactive compounds, fats, and carbohydrates.