Casein Protein — Supplements

Slow-digesting milk protein providing sustained amino acid release for overnight muscle protein synthesis.

Overview

Casein is the predominant protein in cow's milk (~80%), forming a gel-like structure in the stomach that results in slow, sustained amino acid absorption over 5-7 hours. This prolonged aminoacidemia makes casein particularly suitable for pre-sleep consumption to support overnight muscle protein synthesis. RCTs demonstrate that 30-40 g of casein before bed enhances overnight MPS, improves recovery, and supports positive nitrogen balance. Casein is also rich in bioactive peptides with antihypertensive and immune-modulating properties.

Indications

  • Overnight muscle protein synthesis
  • Post-exercise recovery
  • Sustained amino acid delivery
  • Total daily protein intake augmentation

Mechanism of Action

Casein forms a gel matrix in the acidic stomach environment, slowing gastric emptying

Dosing

CompoundDoseFrequencyNotes
Casein Protein30 gOnce daily (before bed)Micellar casein preferred for sustained release; mix with water or milk

Evidence Grade

GRADE C

Safety & Contraindications

  • Contraindicated in milk protein allergy (distinct from lactose intolerance)
  • May cause bloating or digestive discomfort in some individuals
  • Micellar casein is slower-digesting than casein hydrolysate
  • Check for added sugars and artificial ingredients in commercial products