What is the maximum recommended dose of melatonin (melatonin) per day?

Maximum Recommended Dose of Melatonin

The maximum recommended dose of melatonin is 15mg per day for adults, with lower doses often being more effective and having fewer side effects than higher doses. 1

Dosing Recommendations by Age Group

Adults

• Start with 3mg of immediate-release melatonin for sleep disorders, with dose titration in 3mg increments if needed 1
• Positive results for Delayed Sleep-Wake Phase Disorder (DSWPD) in adults have been observed with 5mg doses taken between 19:00-21:00 for a period of 28 days 2
• If ineffective after 1-2 weeks, consider increasing by 3mg increments up to a maximum of 15mg 1
• Timing is critical: melatonin should be taken 1.5-2 hours before desired bedtime for optimal effect 1

Children and Adolescents (6-12 years)

• For children with DSWPD without comorbidities: 0.15 mg/kg (approximately 1.6-4.4 mg) has shown optimal results 2
• For children with DSWPD and psychiatric comorbidities: 3-5 mg of fast-release melatonin 2
• Weight-based approach: 3 mg if <40 kg and 5 mg if >40 kg 2

Dose-Response Relationship

• Lower doses (0.5-5mg) are similarly effective for jet lag, with 5mg providing better sleep quality than 0.5mg 3
• Doses above 5mg appear to be no more effective for jet lag prevention 3
• Short-lived higher peak concentration works better than slow-release formulations 3
• Higher doses (≥10mg) are associated with increased adverse events such as drowsiness, headache, and dizziness 4

Safety Considerations

• No serious adverse reactions have been documented with melatonin use across age groups 2
• Morning grogginess and "hangover" effects are more common with higher doses due to melatonin's half-life extending into morning hours 1
• Gastrointestinal upset is reported more frequently at higher doses 1, 4
• Use with caution in patients taking warfarin or those with epilepsy due to potential interactions 1, 3
• Long-term safety data beyond several months is limited, though available evidence suggests good tolerability 1

Important Clinical Considerations

• Higher doses (10mg) may cause receptor desensitization or saturation, potentially disrupting normal circadian signaling mechanisms 1
• In older adults, doses between 1-6mg appear effective for improving sleep, with no clear dose-response relationship identified 5
• Pharmacokinetic studies in older adults show that even low-dose melatonin (0.4mg) produces substantially higher blood levels than physiologic levels 6
• High-dose melatonin (4mg) can maintain elevated blood levels for approximately 10 hours, potentially extending beyond the typical sleep period 6
• Melatonin is regulated as a dietary supplement in the US, raising concerns about purity and reliability of stated doses 1, 7

Practical Algorithm for Melatonin Use

1. Start with lowest effective dose based on age and condition:
   • Adults: 3mg
   • Children 6-12 years: 0.15 mg/kg or 3-5mg with psychiatric comorbidities 2, 1
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, increase dose in 3mg increments up to maximum of 15mg for adults 1
5. Choose United States Pharmacopeial Convention Verified formulations when possible for more reliable dosing 1