Melatonin Dosing Recommendations
Direct Answer
For chronic insomnia in adults, do not use melatonin—the American Academy of Sleep Medicine explicitly recommends against it due to minimal efficacy. 1, 2 For circadian rhythm disorders like Delayed Sleep-Wake Phase Disorder (DSWPD), use 3-5 mg of immediate-release melatonin taken between 19:00-21:00 for adults and 0.15 mg/kg taken 1.5-2 hours before bedtime for children without comorbidities. 1, 3
Clinical Algorithm for Melatonin Dosing
Step 1: Identify the Indication
Primary/Chronic Insomnia:
- Do NOT prescribe melatonin for sleep onset or maintenance insomnia in adults. 1, 2
- The American Academy of Sleep Medicine issued a weak recommendation against melatonin based on very low quality evidence showing only a 9-minute reduction in sleep latency (95% CI: 2-15 minutes) compared to placebo. 1
- Meta-analysis of 2 mg doses showed no clinically significant improvements in total sleep time, wake after sleep onset, or sleep quality. 4, 2
- Instead, consider FDA-approved hypnotics (zolpidem 10 mg, eszopiclone 2-3 mg) or cognitive behavioral therapy for insomnia (CBT-I). 1
Circadian Rhythm Disorders (DSWPD, Non-24-Hour Sleep-Wake Disorder):
Step 2: Age-Specific Dosing
Adults with DSWPD:
- Dose: 3-5 mg immediate-release melatonin 1, 3, 2
- Timing: Between 19:00-21:00 (7-9 PM), which is 1.5-2 hours before desired sleep onset—NOT at bedtime. 1, 2
- Duration: Minimum 28 days to assess efficacy. 1, 3
- Expected benefit: Reduction in sleep latency by 38-44 minutes and increase in total sleep time by 41-56 minutes. 2
- This recommendation applies to adults both with and without comorbid depression. 2
Children with DSWPD (No Comorbidities):
- Dose: 0.15 mg/kg 1, 3
- Timing: 1.5-2.0 hours before habitual bedtime 1, 3
- Duration: As little as 6 nights has demonstrated effectiveness. 3
Children with DSWPD and Psychiatric Comorbidities (including Autism Spectrum Disorders):
Blind Adults with Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD):
- Dose: 0.5-10 mg (typically start with 5 mg) 1
- Timing: Either 1 hour before preferred bedtime OR at a fixed time (21:00) 1
- Duration: 26-81 days 1
- Efficacy: Odds ratio for entrainment of 21.18 (95% CI: 3.22-39.17). 1
Elderly Patients (>55 years):
- Prolonged-release melatonin 2 mg may provide modest benefit, though evidence quality is low. 4, 3
- The American Academy of Sleep Medicine's recommendation against melatonin for chronic insomnia still applies to elderly patients. 1, 2
- One study showed significant reduction in sleep latency specifically in the 65-80 year age group (−19.1 min with melatonin vs −1.7 min with placebo at 3 weeks). 4
Step 3: Formulation Selection
Immediate-Release vs. Prolonged-Release:
- Immediate-release formulations are preferred for most circadian rhythm disorders. 1, 3
- Slow-release melatonin appears less effective than immediate-release for sleep onset. 3
- The relative ineffectiveness of 2 mg slow-release melatonin suggests that a short-lived higher peak concentration works better. 4
Quality Control:
- Choose United States Pharmacopeial Convention Verified formulations when possible for more reliable dosing. 3
- Over-the-counter melatonin products vary widely in actual content. 3
Step 4: Dose Optimization
Effective Dose Range:
- 3-5 mg is the optimal therapeutic range for most circadian disorders. 1
- Daily doses between 0.5 and 5 mg are similarly effective, except that people fall asleep faster and sleep better after 5 mg than 0.5 mg. 4
Maximum Dosing:
- Doses above 5 mg appear to be no more effective for typical sleep disorders. 4
- Maximum dose is 12-15 mg, used only for specific conditions like REM sleep behavior disorder. 1, 3
- Doses above 10 mg risk receptor desensitization with no additional benefit. 1
Safety Profile and Contraindications
Common Mild Side Effects:
- Morning headache, morning sleepiness, and gastrointestinal upset. 1, 3
- Morning grogginess and "hangover" effects are more commonly reported with higher doses. 3
Serious Adverse Events:
- No serious adverse reactions have been documented across age groups in controlled trials. 1, 3
- Meta-analysis of high-dose studies (≥10 mg) showed melatonin did not cause a detectable increase in serious adverse events (Rate Ratio = 0.88 [0.52,1.50], p = .64). 5
Specific Contraindications/Cautions:
- Warfarin users: Case reports suggest potential interactions; use caution. 1, 3, 6
- Epilepsy: Case reports suggest people with epilepsy may come to harm from melatonin. 1, 3, 6
- Wrong timing: Administering melatonin early in the day can cause sleepiness and delay adaptation to local time, worsening circadian misalignment. 1, 6
Pediatric Safety:
- No significant differences in pubertal development have been observed in children using melatonin compared to non-users. 3
Critical Pitfalls to Avoid
Timing Errors:
- Do not administer melatonin at bedtime for circadian rhythm disorders—it must be given 1.5-2 hours before desired sleep onset. 1, 2
- If taken at the wrong time (early in the day), melatonin is liable to cause sleepiness and delay adaptation to local time. 6
Inappropriate Use for Insomnia:
- Do not prescribe melatonin for primary insomnia—it performs poorly compared to FDA-approved hypnotics. 1, 2
- The American Academy of Sleep Medicine explicitly advises against this practice. 1, 2
Dose Escalation Without Benefit:
- Do not exceed 5 mg for typical circadian disorders—higher doses do not improve efficacy and may cause receptor desensitization. 4, 1
Special Populations
Jet Lag:
- Melatonin is remarkably effective in preventing or reducing jet-lag. 6
- Dose: 0.5-5 mg taken close to target bedtime at destination (10 PM to midnight). 6
- The benefit is likely to be greater the more time zones are crossed, and less for westward flights. 6
- Number needed to treat (NNT) is 2. 6
REM Sleep Behavior Disorder:
- Dose: 3-12 mg at bedtime 3