If a young guy drinks a shake with 25 grams of whey protein, his body absorbs more essential amino acids over 6 hours compared to drinking the same amount of casein protein.

If a young guy drinks a protein shake with a mix of whey and casein, his body absorbs the important amino acids about as well as with pure whey—and better than with pure casein—over the next 6 hours.

If young guys drink a protein shake with micellar casein, their bodies show lower levels of key amino acids after eating compared to when they drink whey or a mix of whey and casein — based on blood tests over 6 hours.

If young, healthy guys work out and then drink a whey protein shake based on their lean body weight, their bodies will absorb more amino acids than if they drank the same amount of cricket or pea protein.

For healthy guys, drinking regular milk protein gives your body more usable protein building blocks over 5 hours than taking just whey or just casein alone.

When healthy guys drink more whey protein, their bodies absorb more of an important amino acid called phenylalanine—about 10% more when they take a higher dose.