| Adults (18 years and older) | ||
| Disorder | Dosage (milligrams) | When |
| Alzheimer’s disease (sleep disturbances) | 0.5 | nightly, 1 hr before bedtime |
| Bipolar disorder (sleep disturbances) | 10 | nightly by mouth |
| Cancer | 10 to 50, most commonly 20 | nightly |
| Circadian rhythm entraining (in blind persons) | 5 to10 | nightly |
| Critical Illness / ICU sleep disturbance | 3 | nightly |
| Delayed sleep phase syndrome | 5 | 5 hrs before bedtime |
| Depression (sleep disturbances) | 5 | nightly |
| Headache prevention | 5 to 10 | nightly |
| Hypertension | 1 to 3 | short periods of time |
| Insomnia in the elderly | 3 to 5 | 30 – 120 min before bedtime |
| Insomnia of unknown origin (in the non-elderly) | 1 to 5 | nightly |
| Jet lag | 0.1 to 0.5, 5 and 8 | Target bedtime at the destination |
| Schizophrenia (sleep disturbances) | 2 | (not stated) |
| Seasonal affective disorder | 0.25 to 5 | daily |
| Sleep enhancement in healthy people | 0.1 to 6 | 30 – 60 minutes before bedtime |
| Children (younger than 18 years)There is limited study of melatonin supplements in children, and safety is not established. Use of melatonin should be discussed with the child’s physician prior to starting. | ||
| Disorder | Dosage (milligrams) | When |
| Circadian rhythm entraining in blind children | 2.5 to 10 | nightly |
| Preoperative anxiety | 0.1, 0.25 or 0.5 per kilogram (of child’s weight?) | (not stated) |
| Seizure disorder in children | 5 to 10 | nightly |
| Sleep disturbances in children with neuro-psychiatric disorders (mental retardation, autism, psychiatric disorders) | 0.5 to 10 | nightly |
