Melatonin

Tier 2 — promising · Sleep onset · Jet lag · Circadian

Melatonin is the body's primary circadian hormone, regulating the sleep-wake cycle. Multiple meta-analyses confirm it shortens sleep-onset latency by approximately 7 minutes in healthy adults and is effective for jet lag and shift-work realignment. A 2025 meta-analysis (Alghamdi, PMID 41647028) confirmed significant sleep-onset latency reduction in clinical populations (SMD -0.63). Most US commercial products contain 5–10 mg — 10–30 times above the 0.3–1 mg range shown to be optimal. Clinically meaningful drug interactions exist with anticoagulants, immunosuppressants, and sedatives. Use…

Dose: 0.3–1 mg taken 30–60 min before bed; use situationally. Avoid habitual nightly use above 1 mg.