How do you counsel older adults regarding the use of melatonin (dose and timing) for sleep-related problems?

Although many patients take up to 10 mg of melatonin, in older adults, the data support doses in the 2-4 mg range (dose response peaks at 4 mg for sleep). I find 30 minutes is not long enough prior to desired sleep time, and I try to give it to hospitalized older patients at about 7 pm so they can fall asleep at 9-10. I think the 30-minute time comes from jet-lag research, which is a different problem. I also add a gram of acetaminophen for older patients before bed when safe and use sleep promotion protocols whenever possible.

Melatonin has a weak hypnotic (i.e., sleep-inducing) effect. It helps people to fall asleep but not to stay asleep. It is not effective in people with chronic insomnia, but it is perfectly safe in low doses (i.e., below 10 mg) and can be helpful for occasional problems with falling asleep. For sleep-onset problems, it should be taken about 1 hour before the desired sleep time. If being used for circadian rhythm issues (e.g., advanced sleep phase or delayed sleep phase), the timing is more nuanced, and a sleep referral should be considered. Similarly, for people who feel they need melatonin on a nightly basis, a sleep referral should be considered.

Melatonin is likely helpful, but patients need to feel comfortable that the melatonin they bought actually contains melatonin, so it's best to suggest that they buy products that have been separately tested. I also feel the need to keep circadian rhythms in mind, so I try to have patients take it as close to 10 PM as possible.