Melatonin Dosing Guidelines
For adults with sleep disorders, the usual dose of melatonin ranges from 1-5 mg taken 30-60 minutes before bedtime, with 3 mg being the most common starting dose. 1, 2
Adult Dosing
- For REM sleep behavior disorder (RBD), the starting dose is usually 3 mg of immediate-release melatonin at bedtime, which may be titrated up in 3 mg increments to a maximum of 15 mg as needed 1
- For adults with delayed sleep-wake phase disorder (DSWPD), 5 mg taken between 19:00-21:00 has shown positive results in clinical studies 1
- For jet lag prevention, doses between 0.5-5 mg are similarly effective when taken close to the target bedtime (10 pm to midnight) at the destination 3
- Higher doses (above 5 mg) do not appear to provide additional benefits for most sleep disorders 3, 4
Pediatric Dosing
- For children with no comorbidities, weight-based dosing of 0.15 mg/kg has shown optimal results 1
- For children with psychiatric comorbidities (such as ADHD), fast-release melatonin at 3-5 mg is recommended (3 mg if <40 kg; 5 mg if >40 kg) 1
- Effective doses by age group 2:
- Children (6-12 years): 0.5-3 mg
- Adolescents: 3-5 mg
Formulation Considerations
- Immediate-release formulations appear more effective than sustained-release for most sleep disorders 1, 3
- Fast-dissolve tablets are available as dietary supplements in the US 5
- The short-lived higher peak concentration of immediate-release melatonin works better than slow-release formulations for conditions like jet lag 3
Safety Profile
- Melatonin is generally well-tolerated with few side effects at recommended doses 2, 4
- Common side effects include morning headache, morning sleepiness, and rarely delusions/hallucinations 1
- Higher doses (≥10 mg) may increase the risk of minor adverse events such as drowsiness, headache, and dizziness 4
- Long-term safety data is limited, but melatonin at low to moderate doses (≤5-6 mg daily) appears safe 6
Important Considerations
- Timing of administration is crucial - taking melatonin at the wrong time (early in the day) can cause sleepiness and delay adaptation to local time 3
- In the US, melatonin is classified as a dietary supplement with no regulatory oversight of manufacturing, resulting in variable concentrations between products 6
- Melatonin requires a prescription in the European Union and United Kingdom, while it's available over-the-counter in the US and Canada 1
- Caution is advised in patients with epilepsy and those taking warfarin, as case reports suggest potential interactions 3
Remember that melatonin's effectiveness for sleep disorders is modest for most people, and its soporific effects are most evident following daytime administration 7.