What are the recommended dosages for melatonin (melatonin)?

Melatonin Dosing Recommendations

The American Academy of Sleep Medicine recommends against using melatonin for chronic insomnia in adults, but when used for circadian rhythm disorders, doses of 3-5 mg taken between 19:00-21:00 are most effective. 1, 2

For Chronic Insomnia (NOT Recommended)

The American Academy of Sleep Medicine explicitly suggests clinicians NOT use melatonin for sleep onset or sleep maintenance insomnia in adults. 1 This weak recommendation is based on:

• Minimal efficacy: 2 mg doses showed only a 9-minute reduction in sleep latency compared to placebo (95% CI: 2-15 minutes) 1
• Poor quality improvement: Only small subjective improvement in sleep quality with no meaningful objective benefits 1
• Quality of evidence: Very low, with benefits approximately equal to harms 1

The evidence demonstrates that melatonin performs poorly compared to FDA-approved hypnotics for primary insomnia. 1

For Circadian Rhythm Disorders (Recommended)

Delayed Sleep-Wake Phase Disorder (DSWPD) - Adults

Start with 3-5 mg of immediate-release melatonin taken between 19:00-21:00 for at least 28 days. 2

• Timing is critical: Must be taken 2-4 hours before habitual bedtime to avoid causing daytime sleepiness or delaying adaptation 3, 4
• Dose titration: If needed, increase in 3 mg increments, though doses above 5 mg show no additional benefit 2, 3
• Formulation matters: Immediate-release is superior to slow-release for sleep onset 2, 3

Delayed Sleep-Wake Phase Disorder - Children

Without comorbidities: Use weight-based dosing of 0.15 mg/kg taken 1.5-2.0 hours before habitual bedtime for at least 6 nights 2

With psychiatric comorbidities (including autism spectrum disorders):

• <40 kg: 3 mg fast-release melatonin 2
• >40 kg: 5 mg fast-release melatonin 2
• Timing: Administer at 18:00-19:00 for 4 weeks 2

Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD) - Blind Adults

Use 0.5-10 mg melatonin taken either 1 hour before preferred bedtime or at a fixed time (21:00) for 26-81 days. 1

• Efficacy: Odds ratio for entrainment is 21.18 (95% CI: 3.22-39.17), meaning melatonin is ~21 times more likely to achieve entrainment than placebo 1
• Dose range: Studies show 0.5-5 mg are similarly effective, though 5 mg produces faster sleep onset 1, 3

Jet Lag

Use 0.5-5 mg taken close to target bedtime (22:00-midnight) at destination. 3

• Most effective: For flights crossing ≥5 time zones, particularly eastward travel 3
• Number needed to treat: 2 (remarkably effective) 3
• Timing warning: Taking melatonin early in the day causes sleepiness and delays adaptation 3

Elderly Patients (≥55 years)

Prolonged-release melatonin 2 mg may provide modest benefit, though evidence quality is low. 2

• The American Academy of Sleep Medicine's recommendation against melatonin for insomnia applies to all adults, including elderly 1, 2
• For circadian disorders in elderly, use standard adult dosing (3-5 mg immediate-release) 5, 6

Critical Dosing Principles

Dose-Response Relationship

• 0.3-1.0 mg: Raises serum melatonin to physiologic nocturnal levels, effective for sleep onset when given 2-4 hours before bedtime 4
• 3-5 mg: Optimal therapeutic range for most circadian disorders 2, 3
• >10 mg: Risk of receptor desensitization with no additional benefit 2, 7
• Maximum dose: 12-15 mg (used only for specific conditions like REM sleep behavior disorder) 2

Timing Considerations

Phase Response Curve matters: 7

• Silent zone (includes DLMO): Melatonin induces sleep but does NOT shift circadian clock
• Delay zone: Early administration delays circadian rhythm
• Advance zone: Late evening administration advances circadian rhythm

For circadian adjustment: Must time dose according to desired phase shift, not just sleep onset 3, 7

Safety Profile and Contraindications

No serious adverse reactions documented across age groups. 1, 2

Common mild side effects (dose-dependent): 2

• Morning headache
• Morning sleepiness/"hangover" (more common with doses >5 mg)
• Gastrointestinal upset

Specific contraindications/cautions: 2, 3

• Warfarin users: Case reports suggest potential interaction
• Epilepsy: Potential for harm based on case reports
• Wrong timing: Can worsen circadian misalignment if taken at inappropriate times

Formulation Quality

Choose United States Pharmacopeial Convention Verified formulations when possible for reliable dosing. 2

• Quality control is essential as melatonin is sold as a dietary supplement in the U.S. 2, 8
• Typical over-the-counter formulations contain 3 mg tablets 8

Clinical Algorithm

For primary insomnia: Do not use melatonin; consider FDA-approved hypnotics (zolpidem 10 mg, eszopiclone 2-3 mg, or others) 1

For DSWPD in adults: Start 3-5 mg immediate-release at 19:00-21:00 × 28 days 2

For DSWPD in children without comorbidities: Calculate 0.15 mg/kg, give 1.5-2 hours before bedtime × 6+ nights 2

For DSWPD in children with psychiatric comorbidities: Give 3 mg (<40 kg) or 5 mg (>40 kg) at 18:00-19:00 × 4 weeks 2

For N24SWD in blind adults: Start 5 mg at 21:00 or 1 hour before preferred bedtime × 26+ days 1

For jet lag: Give 0.5-5 mg at target bedtime (22:00-midnight) starting on arrival, continue for several days 3