What is the maximum recommended dose of melatonin (N-acetyl-5-methoxytryptamine) for adults?

Maximum Recommended Dose of Melatonin for Adults

The maximum recommended dose of melatonin for adults is 15 mg, though most adults should use 1-5 mg for optimal effectiveness with minimal side effects. 1

Dosage Guidelines by Population

The American Academy of Sleep Medicine provides the following dosage recommendations:

• General adults: 1-5 mg approximately 1-2 hours before bedtime 1
• Adults with Delayed Sleep-Wake Phase Disorder (DSWPD): 5 mg taken between 7:00-9:00 PM 1
• Patients with REM Sleep Behavior Disorder: Starting with 3 mg at bedtime, which may be titrated up to 15 mg if needed 1
• Elderly patients: Starting with lower doses (1-2 mg) and titrating as needed 1

Efficacy and Safety Considerations

Efficacy

• Melatonin has a modest effect on sleep onset in adults, with research showing a mean reduction in sleep latency of only 9 minutes compared to placebo 1
• Higher doses (5 mg) have been shown to significantly increase sleep efficiency during both biological day and night, mainly by increasing Stage 2 non-REM sleep and slightly shortening awakenings 2
• Doses between 0.5 and 5 mg are similarly effective for jet lag, though 5 mg may help people fall asleep faster and sleep better than lower doses 3

Safety Profile

• Melatonin at low to moderate dosages (approximately 5-6 mg daily or less) appears safe for long-term use 4
• A systematic review of higher doses (≥10 mg) found that melatonin appears to have a good safety profile, though it may increase the risk of minor adverse events such as drowsiness, headache, and dizziness 5
• Doses above 5 mg do not appear to be more effective for most applications, particularly for jet lag 3

Administration Guidelines

For optimal effectiveness:

• Take melatonin on an empty stomach 1
• Administer 1-2 hours before bedtime 1
• Typical target bedtime should be between 10 pm to midnight 1

Special Considerations and Cautions

Potential Drug Interactions

• Exercise caution in patients with epilepsy, hepatic impairment, or those taking warfarin due to potential interactions 1, 3
• Consider potential drug interactions when patients are on multiple medications 1

Monitoring Recommendations

• Start with a low dose (1-2 mg) and monitor for excessive sedation or changes in mood, especially during the first few days 1
• Regular monitoring for efficacy and side effects is essential 1
• Periodically attempt to discontinue melatonin treatment to assess continued need 1

Common Pitfalls to Avoid

1. Incorrect timing: Taking melatonin early in the day can cause sleepiness and delay adaptation to local time 3
2. Overreliance on medication: Melatonin should be part of a broader approach to improving sleep, including non-pharmacological interventions 1
3. Quality concerns: In the U.S., melatonin is classified as a dietary supplement with no regulatory oversight of manufacturing, resulting in wide variations between product labels and actual content 4
4. Slow-release formulations: These may be less effective than immediate-release forms for some applications, as a short-lived higher peak concentration appears to work better 3

Remember that melatonin should be used as part of a comprehensive sleep management approach that includes maintaining consistent sleep-wake schedules, creating a dark and quiet bedroom environment, and reducing evening exposure to blue light from electronic devices 1.