What are the proper and effective doses of melatonin (N-acetyl-5-methoxytryptamine)?

Proper and Effective Doses of Melatonin

For most adults with sleep disorders, melatonin should be started at 1-2 mg for elderly patients and 3 mg for younger adults, taken 1-2 hours before bedtime, with dose titration in 1-3 mg increments if needed based on response. 1, 2

Adult Dosing Recommendations

• The American Academy of Sleep Medicine recommends 5 mg of melatonin taken between 19:00-21:00 for adults with Delayed Sleep-Wake Phase Disorder (DSWPD) 1
• For general sleep disorders in adults, start with 3 mg of immediate-release melatonin, with dose titration in 3 mg increments if needed 1
• For elderly patients (65+ years), start with a lower dose of 1-2 mg immediate-release melatonin to better mimic physiological circadian rhythm 2
• Prolonged-release melatonin at 2 mg has shown significant reduction in sleep latency specifically in elderly patients (65-80 years) 2, 3
• Commercially available melatonin supplements typically come in 3 mg tablets as indicated on FDA-approved labeling 4

Dosing Based on Clinical Condition

• For Delayed Sleep-Wake Phase Disorder (DSWPD):

  • Adults: 5 mg taken between 19:00-21:00 for at least 28 days 1
  • Children without comorbidities: 0.15 mg/kg taken 1.5-2.0 hours before habitual bedtime 1
  • Children with psychiatric comorbidities: 3 mg if <40 kg or 5 mg if >40 kg 1

• For primary insomnia:

  • The American Academy of Sleep Medicine suggests against using melatonin for primary insomnia in adults (weak recommendation) 3
  • This recommendation is based on trials using 2 mg doses, which showed minimal efficacy for sleep onset, maintenance, or quality 3
  • Despite this recommendation, melatonin is widely used for insomnia with doses ranging from 1-5 mg in adults 5

• For jet lag:

  • Doses between 0.5 and 5 mg are similarly effective when taken close to target bedtime at destination 6
  • 5 mg appears to help people fall asleep faster and sleep better than 0.5 mg 6
  • Doses above 5 mg do not appear to be more effective 6

Age-Specific Dosing Considerations

• Children (with sleep disorders): 0.5-3 mg 5
• Adolescents: 3-5 mg 5
• Adults: 1-5 mg 5
• Elderly: 1-6 mg, but starting at 1-2 mg is recommended 2, 5

Important Clinical Considerations

• Lower doses of melatonin may be more effective than higher doses due to potential receptor desensitization with higher doses 1
• Morning grogginess and "hangover" effects are more commonly reported with higher doses 1
• If no improvement is seen with initial dosing after 3 weeks, consider increasing the dose in 1-3 mg increments 2
• Slow-release melatonin appears less effective than immediate-release formulations for sleep onset 3
• Timing of administration is critical - if taken too early in the day, melatonin can cause sleepiness and delay adaptation to local time 6

Safety Profile

• Melatonin has few immediate side effects except drowsiness 7
• No serious adverse reactions have been documented across age groups 1
• Long-term melatonin administration at low to moderate dosages (≤5-6 mg daily) appears safe 8
• Caution is advised when prescribing to patients taking warfarin and to patients with epilepsy due to case reports of potential interactions 3, 6
• Unlike benzodiazepines, melatonin is not on the American Geriatrics Society Beers Criteria list of potentially inappropriate medications for older adults 2

Quality Control Considerations

• In the United States, melatonin is classified as a dietary supplement without FDA oversight of manufacturing 8
• Choose reputable formulations when possible for more reliable dosing 1
• United States Pharmacopeial Convention Verified formulations can be considered most reliable 3

Common Pitfalls to Avoid

• Using doses that are too high, which may cause receptor desensitization and reduced efficacy 1
• Incorrect timing of administration, which can disrupt circadian rhythms 6
• Expecting immediate results - some conditions require consistent use for several weeks 1, 2
• Relying solely on melatonin for severe or chronic insomnia without addressing underlying causes 9