Casein Protein
Casein forms a gel in the stomach and releases amino acids over several hours, which makes it useful before long gaps without food — most obviously overnight.
Effective dose
30–40 g, typically 30–60 minutes before bed.
Timing
Before sleep, or before any stretch of five or more hours without food.
What it is
Casein is the other major milk protein, roughly 80% of milk's protein content. Micellar casein is the least processed form and the one that digests slowly.
How it works
Where whey spikes blood amino acids quickly, casein produces a lower, longer plateau. That sustained supply reduces muscle protein breakdown during the hours you are not eating.
What the research shows
- Pre-sleep casein raises overnight muscle protein synthesis in trained people.
- Effects are most useful for people who struggle to hit daily protein or train hard in the evening.
Best for
Forms to look for
- Micellar casein powder
- Casein-whey blends
- Cottage cheese and Greek yogurt as whole-food options
What to watch out for
Casein is thick. Mix with more liquid than whey, and skip it if dairy upsets your stomach.
Sourcing partners
Coming soonWe are onboarding a short list of vetted suppliers for casein protein, each with published certificates of analysis and third-party identity testing. Direct purchasing will open here once those partners are live.
FAQs
Is casein better than whey?
Neither is better overall. Whey wins for speed around training; casein wins for sustained release overnight.
Related on SportsNutrition.com
Educational information only, not medical advice. Talk to your physician or a registered dietitian before starting a supplement, especially if you are pregnant, nursing, managing a health condition, or taking medication.