Melatonin
Strong evidence- Typical use case
- Sleep-onset trouble, jet lag, or schedule-shift problems where circadian timing is the main issue.
- Time to effect
- Usually 30–60 minutes for bedtime use; schedule effects depend on timing consistency.
- Safety summary
- Low-to-moderate risk for many adults, but review pregnancy, autoimmune conditions, morning grogginess, and sedative stacking.
- Why it made the shortlist
- It is the most direct fit when the decision is about sleep timing rather than general relaxation.
Main tradeoff: Not the best default for chronic stress-driven insomnia or people who wake groggy from small doses.
Risk label: Needs review