At what age and dose is melatonin (melatonin) considered safe?

Melatonin Safety and Dosing by Age Group

Melatonin is considered safe for children ages 6 and older at appropriate weight-based dosing, with 0.15 mg/kg showing optimal results for children without comorbidities and 3-5 mg for children with psychiatric comorbidities. 1

Safety Profile by Age Group

Children (6-12 years)

• For children with Delayed Sleep-Wake Phase Disorder (DSWPD) without comorbidities, melatonin at 0.15 mg/kg (approximately 1.6-4.4 mg) is effective and has a moderate level of evidence 1
• For children with DSWPD and psychiatric comorbidities (such as ADHD), fast-release melatonin at 3-5 mg is recommended 1
• Weight-based dosing approach: 3 mg if <40 kg and 5 mg if >40 kg has shown effectiveness 1
• Timing: Administration 1.5-2 hours before habitual bedtime for optimal effect 1

Adolescents

• Similar dosing as for children with psychiatric comorbidities: 3-5 mg 2
• No significant adverse effects have been reported in long-term follow-up studies of adolescents using melatonin 1

Adults

• Doses of 1-5 mg are typically effective for adults with sleep disorders 2
• Higher doses up to 10 mg appear safe in short-term use but may increase minor adverse effects such as drowsiness, headache, and dizziness 3

Elderly

• Doses of 1-6 mg are considered safe and effective 2, 4
• Lower doses (0.5-6 mg) have shown effectiveness in decreasing sleep latency in elderly insomniacs 4
• Most effective in elderly who chronically use benzodiazepines or have documented low melatonin levels 4

Safety Considerations

• No serious adverse reactions have been documented in relation to melatonin use across age groups 1
• Long-term safety data in children is limited, but available evidence is reassuring 1
• Potential concerns about effects on reproductive development have not been substantiated in follow-up studies 1
• A questionnaire-based study assessing Tanner stages in children/adolescents using melatonin (mean dose ~3 mg) for approximately 3 years showed no significant differences in pubertal development compared to non-users 1
• Acute toxicity studies in animals showed toxic effects only at extremely high doses (>400 mg/kg), thousands of times higher than recommended human doses 5

Common Side Effects

• Mild side effects may include drowsiness, headache, and dizziness 3
• Gastrointestinal upset has been reported at higher doses 1
• Morning sleepiness may occur in some children 1

Important Caveats and Recommendations

• Melatonin is regulated as a dietary supplement, not a medication, raising concerns about purity and reliability of stated doses 1
• Choose United States Pharmacopeial Convention Verified formulations when possible for more reliable dosing 1
• Melatonin should be used with caution in patients taking warfarin or those with epilepsy due to potential interactions 1
• Periodic reassessment is recommended; consider stopping treatment at least once a year to reassess need 5
• No data supports melatonin use in children under 2 years of age, and its use in this population is concerning due to lack of safety data 6
• For children with autism spectrum disorders, melatonin has shown effectiveness for improving sleep duration, latency, and reducing night wakings 1

Algorithm for Melatonin Use

1. Start with lowest effective dose based on age:

   • Children 6-12 years: 0.15 mg/kg (without comorbidities) or 3 mg (<40 kg)/5 mg (>40 kg) with psychiatric comorbidities 1
   • Adolescents: 3-5 mg 2
   • Adults: 1-5 mg 2
   • Elderly: 0.5-6 mg 4

2. Administer 1.5-2 hours before desired bedtime 1

3. Assess response after 1-2 weeks 1

4. If ineffective and no adverse effects, consider gradual dose increase within recommended range 1

5. Reassess need periodically and consider annual medication holiday 5