Whey

Studies in people

• Benefit

  Muscle strength in older adults²

  In older people, whey protein helped physical function, and with vitamin D it also helped muscle strength.

• Benefit

  Muscle strength in older women³

  In postmenopausal women, whey protein helped arm and leg muscle only when combined with weight training.

• Benefit

  Muscle recovery after exercise⁴

  In young, healthy adults, whey protein had small to medium benefits for muscle function recovery after hard workouts.

• No harm found

  Acne severity in men⁵

  In men with acne, whey protein did not make acne worse over six months.

• Benefit

  Muscle damage after exercise⁶

  In men, whey protein after hard exercise lowered blood signs of muscle damage, but soreness and fitness tests did not change.

• Open question

  Muscle recovery after running⁷

  Runners who took whey had less muscle breakdown after a marathon and ran farther in twelve minutes.

• Benefit

  Muscle soreness after exercise⁸

  In active women, four days of whey protein hydrolysate improved flexibility and strength recovery after hard exercise.

Study type not stated

• Concern

  Kidney and liver health⁹

  In some studies, long-term heavy use of whey protein was linked to kidney and liver problems.

• Benefit

  Muscle mass as we age¹⁰

  Whey protein helps build and keep muscle, especially with exercise, and may slow muscle loss with age.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least two findings in people. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.