As a sleep physician, most of my clinical encounters involve patients asking about melatonin or already taking it to help them sleep. Almost none of them know the risks that come with it. There is a melatonin epidemic brewing in the US, and the numbers back that up. Melatonin use among US adults quintupled in the last two decades, from 0.4% to 2.1% (NHANES data, 1999-2000 to 2017-2018). Sales surged from $285 million in 2016 to $821 million in 2020 (MMWR, 2022).
The surge exists because melatonin is sold as a dietary supplement in the US. That means it isn’t regulated by the FDA the way medications are.
Pediatric Concerns
The most alarming trend is what’s happening with children. In 2020, melatonin became the most frequently ingested substance among children reported to US poison control centers. Over a 10 year span, poison control centers received 260,435 reports of pediatric melatonin ingestions, a 530% increase. Five children required mechanical ventilation and two died (MMWR, 2022).
A second CDC report found that between 2019 and 2022, melatonin was involved in about 11,000 emergency room visits for unsupervised medication ingestion in infants and young children. Many of these cases involved flavored gummies that kids mistook for candy. Part of the problem is that OTC melatonin products often don’t contain what the label says. One study found melatonin content varied by as much as 465% between lots of the same product, and some gummies contained unlisted serotonin at doses high enough to raise the risk of serotonin toxicity in children.
Dosing and Efficacy
A key aspect of overuse of melatonin is that many consumers use it in apppropriately. A dose response meta analysis found that 3-5mg/day taken approximately 3 hours before desired bedtime was effective. (Journal of Pineal Research. 2024). In my practice, I most commonly hear people taking 5 to 15mg about 30 minutes before bed. Timing matters more than dose. Taken this late and at this dose, melatonin does almost nothing to help you fall asleep faster. It works as a signal to your body that night is approaching, not as a sedative, so it needs time to act before bedtime, not minutes.
Here is an evidence based instagram post on Optimal Timing for Taking Melatonin.
Safety Profile
Although the safety profile of melatonin is not clearly understood, there have been reports of adverse effects. These include but are not limited to;
- Common: daytime sleepiness, headaches, dizziness
- Metabolic effects: impaired glucose intolerance and increased insulin resistence
- Drug interactions: with antihypertensive medications (causing increase in blood pressure during the day) and warfarin
- Long term: suppression of hypothalamic-gonadal axis and increased chance of precocious puberty
My Advice
Melatonin should be administered with clinical supervision, especially in children, adolescents and women of reproductive age
References:
1. Pediatric Melatonin Ingestions | MMWR. 2022. Lelak K, Vohra V, Neuman MI, Toce MS, et al.
2. Optimizing the Time and Dose of Melatonin as a Sleep-promoting Drug | Journal of Pineal Research. 2024. Cruz-Sanabria F, Bruno S, Crippa A, et al.
3. Optimal Timing for Taking Melatonin | Instagram – @dr.snoozz