Last verified: today
Casein Protein
Also known as: micellar casein, sodium caseinate, calcium caseinate, milk protein, beta-casein, slow-release protein
Evidence under review. — Not yet rated
Slow-digesting milk protein that supports muscle performance and may modestly improve cardiovascular markers.
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What it does
Casein is the primary protein found in cow's milk, making up about 80% of milk's protein content. It digests slowly, releasing amino acids steadily over several hours, which makes it popular as a...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
25-50g daily based on study doses
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Found in
What the Science Says
Casein is the primary protein found in cow's milk, making up about 80% of milk's protein content. It digests slowly, releasing amino acids steadily over several hours, which makes it popular as a pre-sleep protein source for muscle recovery and strength. Research also suggests milk protein supplementation, including casein, can modestly reduce total cholesterol, triglycerides, and systolic blood pressure in adults.
What It Doesn't Do
Not proven to build muscle faster than other proteins on its own. Won't significantly lower blood pressure on its own — effects are modest at best. No strong evidence it improves skin, mood, or cognition directly. Pre-sleep timing benefits are still being studied and aren't conclusively superior to other timing strategies.
Evidence-Based Benefits
Pre-sleep casein intake improves anaerobic power and lower-body strength in soccer players.
Moderate EvidenceEffective at: No established dose from provided studies
Milk protein supplementation modestly reduces total cholesterol and triglycerides in adults.
Moderate EvidenceEffective at: No established dose from provided studies
Milk protein supplementation modestly lowers systolic blood pressure in adults.
Moderate EvidenceEffective at: No established dose from provided studies
Milk protein supplementation may support improvements in body composition and anthropometric measures.
Moderate EvidenceEffective at: No established dose from provided studies
Absorption & Bioavailability
Good — casein is well absorbed but digests slowly (over 5-7 hours), which distinguishes it from faster proteins like whey. This slow release is considered a feature for overnight recovery use cases.
Red Flags to Watch For
- Casein is a primary allergen in cow's milk — people with milk allergies should avoid it entirely
- A1 beta-casein (found in most conventional milk) may cause digestive discomfort in some individuals compared to A2-type casein
- High doses (50g/day) used in some studies may exceed what typical supplements provide — check label amounts carefully
- Some products marketed as 'casein' may be blended with other proteins — read ingredient labels to confirm what you're actually getting
Products Containing Casein Protein
See how Casein Protein is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25