A milk protein rich in the amino acid the brain uses to build mood and sleep signals, measurable two hours after a dose. Memory and stress effects appear only in those prone to stress or low mood; the sleep findings disagree. Dosed in the evening; a plausible tool with thin support. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Sleep-onset latency (wearable or diary) | Under 15 minutes | Most consistently improved in trials |
| Pittsburgh Sleep Quality Index global score | 5 or below | Marks the poor sleepers who benefit |
| Plasma ratio of tryptophan to competing amino acids | No established target; track change from own baseline | Confirms the dose reaches the transporter |
| Estimated glomerular filtration rate (cystatin C-based) | Above 90 mL/min/1.73 m² | Detects reduced clearance behind the nitrogen load |
| Blood urea nitrogen | 10–16 mg/dL | Tracks added nitrogen load |
| Insulin-like growth factor 1 | Mid age-adjusted range | Growth signalling from high protein |
| Fasting insulin | Below 5 µIU/mL | Whey fractions are insulin-releasing |
| High-sensitivity C-reactive protein | Below 1.0 mg/L | Screens for low-grade inflammation |
| Milk-specific immunoglobulin E (Bos d 4) | Undetectable, below 0.35 kU/L | Identifies sensitisation that makes dosing dangerous |
Cadence: Sleep metrics continuously, with formal comparison against baseline at 2 and 6 weeks; blood markers at 3 months, then every 6–12 months.