asein is a slow-digesting dairy protein that people often take as a supplement.
It releases amino acids slowly, so people often take it before bed to help with recovery and reduce muscle breakdown while they sleep.
Several studies have shown it helps boost muscle growth, along with a ton of other benefits.
Like Whey, Casein Is Derived From Milk
Milk contains two types of proteins — casein and whey. Casein is 80% of the milk protein, while whey is 20%.
Casein protein is digested slowly, while whey protein digested quickly. This is the biggest difference between these two popular dairy proteins.
There are two main forms:
- Micellar casein: This is the most popular form and is digested slowly.
- Casein Hydrolysate: This form is predigested and rapidly absorbed.
A 33-gram (1.16-ounce) scoop of standard casein protein powder contains 24 grams of protein, 3 grams of carbs and 1 gram of fat (4):
It may also contain various micronutrients (such as calcium), but the exact composition will vary depending on the brand.
Bottom Line: Casein protein is derived from milk. It is a slow-digesting protein that contains all the essential amino acids your body needs.