What is the recommended dose of melatonin (N-acetyl-5-methoxytryptamine) for children?

Melatonin Dosing for Children

For children with sleep disorders, use weight-based dosing of 0.15 mg/kg administered 1.5-2 hours before bedtime for those without comorbidities, or fixed-dose melatonin of 3 mg (<40 kg) or 5 mg (>40 kg) for children with psychiatric comorbidities or autism spectrum disorder. 1

Dosing Algorithm by Clinical Presentation

Children WITHOUT Psychiatric Comorbidities or Neurodevelopmental Disorders

• Start with 0.15 mg/kg of immediate-release melatonin (typically 1.6-4.4 mg range) given 1.5-2.0 hours before the child's habitual bedtime 1, 2
• This weight-based approach is specifically recommended by the American Academy of Sleep Medicine for delayed sleep-wake phase disorder in otherwise healthy children 1
• Treatment can be as short as 6 nights to demonstrate effectiveness 1
• For typically developing children over 2 years old, European experts recommend starting with 1-3 mg given 30-60 minutes before bedtime 3

Children WITH Psychiatric Comorbidities or Autism Spectrum Disorder

• Use fixed-dose fast-release melatonin: 3 mg if child weighs <40 kg, or 5 mg if >40 kg 1, 2
• Administer earlier in the evening (18:00-19:00) for these children 1
• Continue treatment for at least 4 weeks to assess effectiveness 1
• Studies in autism spectrum disorder populations have documented safe use for up to 24 months with continued efficacy 2

Children with Neurodevelopmental Disorders

• Initial dose of 1 mg given 30-40 minutes before bedtime 2
• Can escalate through 2 mg, 6 mg, up to maximum 12 mg based on response over first 4 weeks 4
• In controlled trials, melatonin increased total sleep time by 22-23 minutes and reduced sleep onset latency by 37-45 minutes in this population 1, 4

Timing Considerations

• Administer 1.5-2 hours before desired bedtime for phase advancement (shifting sleep earlier) in children without comorbidities 1, 5
• For children with comorbidities, earlier administration between 18:00-19:00 may be more effective 1
• Consistency in timing relative to bedtime improves outcomes 5

Important Clinical Caveats

Formulation Selection

• Choose immediate-release formulations over slow-release for sleep onset problems, as slow-release (2 mg) formulations are relatively ineffective compared to immediate-release 5
• Select United States Pharmacopeial Convention Verified products when possible, as melatonin is regulated as a dietary supplement with concerns about purity and reliability of stated doses 1, 2

Safety Profile

• No serious adverse reactions have been documented in children at appropriate doses across all age groups 1, 2
• Common mild side effects include morning sleepiness, headache, and gastrointestinal upset, more frequent at higher doses 2
• Long-term studies up to 24 months in children show no significant differences in pubertal development (Tanner stages) compared to non-users 2
• Use caution in children with epilepsy due to case reports of potential interactions 1, 2

Treatment Duration

• Most evidence supports initial treatment periods of 4 weeks or less for assessment 1, 5
• For circadian rhythm disorders like delayed sleep-wake phase disorder, longer treatment (minimum 28 days) is appropriate 5
• Recommend stopping melatonin at least once yearly (preferably during summer holidays) to reassess need, as circadian rhythmicity may change during long-term treatment 6
• Long-term safety data beyond several months is limited, though available evidence up to 24 months in pediatric populations suggests good tolerability 2

When NOT to Use Melatonin

• Avoid in children with dementia and irregular sleep-wake rhythm disorder due to lack of benefit and potential harm 1, 5
• Should not replace behavioral interventions—melatonin is indicated only when sleep hygiene and behavioral therapies have been insufficient 3

Dose Escalation Strategy

• If ineffective after 1-2 weeks at initial dose and no adverse effects are present, consider gradual increase within recommended range 2
• For typically developing children, maximum dose should not exceed 6 mg 2
• Higher doses (10 mg+) may cause receptor desensitization and are associated with more frequent adverse effects like morning grogginess 2