Questions about melatonin may make you drowsy

Melatonin is a popular sleep aid. It is easily the subject of more myths and questions than perhaps any other supplement.

Melatonin is a hormone naturally secreted by the pineal gland in our brains to help us fall asleep. Melatonin supplements are the remedy of choice for a significant portion of the 70 million Americans who experience sleep disorders. They spent $826 million on melatonin supplements in 2020, a 43% increase from the year before, probably fueled by COVID-19 pandemic-related stressors.

Despite this surge, there is a general lack of oversight by the FDA on melatonin and the supplement industry in general. Compared with more regulated doctor-prescribed medications, there is decidedly less evidence-based research on melatonin. Four of the most common questions I encounter are: “Will taking melatonin cause my brain to stop making it?” “Is it safe to give to kids?” “Does it cancel out birth control?” “Is melatonin a sedative?”

Taking a melatonin supplement before bed will not affect the pineal gland’s natural secretion of it. There are many factors that can decrease its production. Aging plays the biggest role in natural reduction of melatonin production. Stress, smoking and disrupted lightdark cycles all decrease production. Exposure to too much light (especially blue light), not getting enough natural sunlight and shift work all interrupt the critical light-dark schedule.

We know that children with medical conditions such as ADHD, autism spectrum disorder and asthma are more susceptible to sleep problems. A 2019 metaanalysis of 18 studies of more than 1,000 children with such conditions showed that melatonin was better than placebos for improving time to fall asleep and total sleep. These studies were inconsistent in their recommendations for dosage and duration. They tracked the children over a brief time, and because melatonin is a hormone, we don’t know the effects it can have on development. A safer long-term strategy is developing and maintaining good bedtime habits.

Even less is known about the interaction between melatonin and birth control. Since both are hormones, there is likely an interaction, but studies have been inconsistent in their results. Research showed an increase in the naturally occurring level of melatonin in those taking birth control, particularly in those with progestin. Yet other studies showed no difference in melatonin in those who took birth control compared with those that didn’t. It is unlikely that taking melatonin will cancel out the contraception from birth control. But since there’s no conclusive evidence and a risk that using both together might cause increased sedation from melatonin, those on birth control should discuss other sleep-promoting options with their doctor.

And finally, most people cling to the myth that melatonin is a sedative. If you’re taking it right before your head hits the pillow, you’re doing it wrong. To get the most out of a melatonin supplement, take it a few hours before bedtime to maximize its effectiveness.

Certainly, there is a high level of evidence that supplementing with as little as 3 milligrams of melatonin can reduce insomnia. It is particularly useful for travelers crossing time zones or for shift workers who frequently alternate between day and night shifts, like me.

As always, discuss your options with your doctor before starting any medication or supplement.

Michael Daignault is a board-certified ER doctor in Los Angeles.