Okay, so why do my friends take it? Dr. Dasgupta explained to me that when it comes to dietary supplements, melatonin is one of the most popular out there, since it’s believed to be a sleep aid. But unfortunately, it’s actually not that potent — so while my friends swear up and down that it helps them sleep at night, it doesn’t actually lull them into an immediate slumber. Instead, when you take melatonin as a supplement, it really just helps to adjust your body’s internal clock, which is beneficial for sleep. “When I’m using melatonin for my patients, I’m really not using it to knock them out,” Dr. Dasgupta said.

So, what does melatonin do? If you take melatonin two hours before your desired bedtime, it might be able to help adjust your body’s clock, Dr. Dasgupta explained. So, for example, if you’ve returned from a trip abroad and you want to actually fall asleep at your normal time, taking melatonin a couple of hours beforehand might help you achieve that goal, though it’s not actually a cure-all for an inability to sleep. “It’s not a very potent hypnotic and when we do use it based on evidence-based medicine from the sleep literature, it’s mainly for circadian-rhythm issues,” he said.

How much should I take? Dr. Dasgupta recommends people take one milligram to three milligrams of pharmaceutical-grade melatonin to help with their circadian rhythm (or jet lag) issues. “Lower doses will suit you just fine,” he told me. The National Institutes of Health notes that melatonin might worsen the moods of people with dementia, or cause uncommon side effects, such as drowsiness, nausea, dizziness, or headaches. No significant side effects have been reported in children, but it may interact with certain medications, so it’s always important to check with your doctor before taking it.

Read More