Casein for Sleep Quality
There is no reliable evidence that plain casein protein improves sleep quality. The only sleep trials used Lactium, a proprietary alpha-s1 casein hydrolysate that is a different product from the casein powder sold for muscle support.
Why this grade7-layer evidence engine
The grade reflects a critical mismatch between what was studied and what people actually buy. Every human sleep trial used alpha-s1 casein hydrolysate (Lactium), a specific bioactive peptide, not ordinary casein protein. Two small randomized trials, n=36 (PMID 39541860) and n=48 (PMID 31252661), reported shorter sleep onset latency and better sleep efficiency in people with disturbed sleep, but both were small and carried industry ties to the Lactium maker. An older trial (PMID 17136040) measured stress symptoms, not validated sleep scores, and a rodent study (PMID 29316237) only suggests a GABA-related mechanism.
Plain casein protein itself has no published trials showing it improves sleep quality; the well-known pre-sleep casein research addresses overnight muscle protein synthesis, not sleep. So the hydrolysate findings cannot be transferred to a tub of casein powder.
Regulators and clinics offer no support for a sleep claim. The FDA lists casein only as a generally recognized food ingredient, and WHO/Codex treat it as a protein-quality benchmark. Major clinical bodies (NIH, Mayo Clinic, Cleveland Clinic, Harvard, sleep specialty societies) do not address casein for sleep at all. For chronic insomnia, cognitive behavioral therapy (CBT-I) is the guideline-recommended first-line option.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.5
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — | C→U 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status