What it is & primary uses
A hormone that signals biological night and helps regulate circadian timing.
Main benefits
- May shorten sleep onset
- Useful for circadian timing and jet lag
Studied protocols
Research doses are grouped by outcome. They describe study designs—not a personal prescription.
0.3–3 mg
- Study duration
- 30–120 minutes before target bedtime; timing depends on goal
- Interpretation
- More is not necessarily better. Product-content accuracy is a major practical limitation.
Up to ~5 mg in many adult studies
- Study duration
- Short term
- Interpretation
- Average benefits were small; clinical populations and circadian disorders differ from healthy sleepers.
04Food sources & equivalents＋
Can food provide a studied amount?
Melatonin occurs in foods such as eggs, fish, nuts, mushrooms and some cereals, but generally in trace and highly variable concentrations.
Trace dietary exposure rather than a milligram supplement dose
- How this was estimated
- A defensible food-to-milligram conversion is not available because reported food values and analytical methods vary widely.
- Important limitation
- Critical reviews conclude that so-called melatonin-rich foods should not be expected to reproduce the physiological effect of milligram-dose supplements.
Food equivalents compare ingredient mass using published composition values. They do not prove equal absorption, formulation, physiological effect, safety or personal need.
Source: Critical review of melatonin-rich foods ↗05How to take it for absorption & tolerance＋
With or without food
Melatonin acts primarily as a circadian signal. A meal can change the timing of absorption, but no universal food rule improves sleep outcomes.
- Practical approach
- Use at a consistent interval before the target bedtime and follow the product instructions.
- Watch for
- Do not use it to cancel late caffeine; monitor next-day drowsiness.
Meal guidance reflects human pharmacokinetic, clinical, official-label or evidence-review sources where available. A food pairing can change absorption or tolerability, but does not make a supplement necessary, effective or safe for every person.
Source: Melatonin pharmacokinetics systematic review ↗06Supplement interaction check＋
An unlisted pair means no established pair-specific interaction was identified in this review—not proof that every dose, product or person is safe.
Evening caffeine can delay the body's melatonin rhythm. In a small pharmacokinetic study using high doses, caffeine also substantially increased exposure to an oral melatonin dose.
Do not use melatonin simply to counter late caffeine. Keep caffeine away from the intended sleep window and review timing with a clinician for shift work or jet-lag protocols.
Both can promote sleepiness. One 2025 randomized trial used 3 mg melatonin with 600 mg/day ashwagandha for eight weeks and reported no clinically significant difference in adverse events, but one trial cannot establish safety for every user or extract.
Monitor next-day drowsiness and do not drive after taking the combination. Review it with a clinician when using sedatives or when liver or thyroid concerns apply.
07Research notes＋
Moderate for circadian timing and small sleep-onset improvements. Effects on total sleep time and quality are modest in primary sleep disorders.
Lower amounts may be sufficient. Product content can vary, and timing is central to the effect.
08Scientific references＋
Peer-reviewed human research and formal evidence reviews. Open each source to inspect the complete paper record.
Melatonin for primary sleep disorders
Dose context: Multiple doses and durations
Reduced sleep latency by ~7 minutes and increased total sleep time by ~8 minutes on average.
Exogenous melatonin and sleep quality
Dose context: 227 meta-analyses across varied populations and protocols
The evidence base is broad but methodologically inconsistent; only a small minority of reviews met all predefined rigor criteria.
09Expert & media references＋
Podcast and practitioner statements are clearly separated from research. They may explain practice or emerging ideas, but do not prove efficacy.