Bodybuilders and athletes have used this supplement for decades.
Like other animal proteins, it contains all the essential amino acids that your own body is unable to produce naturally. Most importantly, it provides a high amount of leucine, which initiates muscle protein synthesis (9, 10, 11).
One study compared those who took casein to two other groups. One consumed whey protein and the other had no protein.
The researchers found that the casein group experienced double the muscle growth and triple the fat loss compared to the placebo group. The casein group also experienced more fat loss than the whey group (13).
It may also enhance long-term muscle mass by reducing protein breakdown. This process occurs on a daily basis when your body is low on energy and amino acids. It’s accelerated during exercise or weight loss (7, 8, 14).