What is the recommended dosage and usage of melatonin (melatonin) for sleep issues?

Melatonin Dosage and Usage for Sleep Issues

For adults with insomnia, melatonin is not recommended as a first-line treatment, while for specific populations such as children with sleep disorders and adults with REM sleep behavior disorder, melatonin can be effective at appropriate doses. 1

Adult Dosing Recommendations

• The American Academy of Sleep Medicine (AASM) suggests that clinicians not use melatonin as a treatment for sleep onset or maintenance insomnia in adults, based on trials of 2 mg doses showing insufficient efficacy 1
• When melatonin is used despite this recommendation, lower doses (3 mg) are often more effective than higher doses, as higher doses may cause receptor desensitization 2
• Start with 3 mg of immediate-release melatonin taken 1.5-2 hours before desired bedtime, with potential increases in 3 mg increments if ineffective after 1-2 weeks 2
• For older adults (>55 years), evidence suggests prolonged-release melatonin 2 mg may provide some benefit, though the quality of evidence is very low 1

Pediatric Dosing Recommendations

• 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 1, 2
• For children with DSWPD and psychiatric comorbidities (e.g., ADHD), fast-release melatonin at 3-5 mg is recommended 1
• Weight-based approach: 3 mg if <40 kg and 5 mg if >40 kg 1, 2
• For children with autism spectrum disorders, melatonin has shown effectiveness for improving sleep duration, latency, and reducing night wakings at doses of 1-6 mg 1
• Timing: Administration 1.5-2 hours before habitual bedtime for optimal effect 1, 2

Special Populations

• For REM Sleep Behavior Disorder (RBD), melatonin 3-12 mg at bedtime is recommended and has been shown to be effective with few side effects 1
• Melatonin is particularly useful for RBD patients with comorbid sleep-disordered breathing, where clonazepam may worsen sleep apnea 1

Safety Profile and Side Effects

• Most common adverse effects include daytime sleepiness (1.66%), headache (0.74%), dizziness (0.74%), and hypothermia (0.62%) 3
• Morning grogginess and "hangover" effects are more commonly reported with higher doses due to melatonin's half-life extending into the morning hours 2
• Gastrointestinal upset has been reported more frequently at higher melatonin doses 2, 3
• Most adverse events resolve spontaneously within a few days or immediately upon withdrawal of treatment 3
• No serious adverse reactions have been documented in relation to melatonin use across age groups 2, 3

Important Considerations

• Melatonin is regulated as a dietary supplement in the US, raising concerns about purity and reliability of stated doses 2, 4
• Choose United States Pharmacopeial Convention Verified formulations when possible for more reliable dosing 2
• Use with caution in patients taking warfarin or those with epilepsy due to potential interactions 2
• Long-term safety data beyond several months is limited, though available evidence suggests good tolerability 2, 3
• Immediate-release formulations are generally preferred for sleep onset issues, while controlled-release may be better for sleep maintenance problems 5, 6

Timing of Administration

• For optimal effect, melatonin should be taken 1.5-2 hours before desired bedtime 1, 2
• Timing is critical for effectiveness, as melatonin works partly by resetting the circadian pacemaker 7
• Low doses (0.3-1.0 mg) given 2-4 hours before habitual bedtime have been shown to decrease sleep onset latency without altering sleep architecture 6

Despite widespread use, the evidence for melatonin's efficacy in treating primary insomnia in adults is limited, while evidence supports its use in specific populations like children with sleep disorders and adults with RBD 1.