This information is provided to help you make an educated choice. Remember to talk with your health-care professional before starting a supplement regimen. Mayo Clinic does not endorse any non-Mayo products or services. Mayo Clinic has authorized Thorne Research to distribute Mayo Clinic health information as part of its commitment to serve as a reliable resource for the public. Published 12/09/16 What is whey protein? Protein is one of three key nutrients that your body needs daily. Protein is considered a macronutrient, along with carbohydrates and fats. Whey protein, one of the primary proteins found in dairy products, accounts for many of the health benefits that dairy products offer. A byproduct of the cheese-making process, whey protein provides substantial amounts of the essential amino acids that are needed to carry out the functions that proteins perform in the body. Whey protein typically is provided as a powder. It can be added to liquids or soft foods (such as oatmeal or applesauce) or blended with ingredients such as ice and fresh fruit to make a smoothie or shake. What are the dietary sources of protein? Protein is found in both animal sources and plant sources. The quality of a protein is based on the amounts and types of amino acids it provides. Typically, animal proteins from meat, fish, poultry, dairy and eggs have more of the amino acids the body needs than do plant proteins, such as amino acids from soybeans, peas, rice and vegetables.