Melatonin Overdose Is on the Rise: 3 Signs to Know

Emily Boynton Fact Checked
Melatonin pills and water
© Marc Tran / Stocksy United

Over the past decade, more adults in the U.S. are taking melatonin supplements to help them get some sleep. 

The desire to take a melatonin pill (or gummy, tablet or tea) to fall and stay asleep makes sense: Who wouldn’t want to feel better-rested? But taking melatonin isn’t always recommended, effective or safe — and, while uncommon, it is possible to overdose on melatonin. 

What is melatonin? 

Melatonin is a hormone produced by the pineal gland located in the middle of your brain. It helps synchronize your circadian rhythm, aka your internal sleep-wake cycle, so you are awake during the day and asleep at night.  

“Melatonin does this by inhibiting the ‘master clock’ of the suprachiasmatic nucleus in our brains. During the day, light activates the master clock, and at night, melatonin inhibits it,” says Dr. Catherine McCall, assistant professor of Psychiatry and Behavioral Sciences at the UW School of Medicine and a sleep medicine expert.

She notes our brains naturally release about 1/3 milligram of melatonin over the course of each night, beginning when it starts to get dark (about two hours before the onset of sleep) and peaking in the middle of the night.  

Should you take a melatonin supplement? 

Melatonin supplements can be helpful in some specific cases, such as coping with jet lag or treating circadian rhythm sleep disorders, but sleep medicine doctors don’t recommend taking the supplement for run-of-the-mill sleep difficulties or for insomnia.  

In fact, most studies on using melatonin to cope with insomnia have either been inconclusive or have not found an overall benefit in taking the supplement.  

Melatonin can also affect some individuals more severely and can interfere with some medications, so you should talk to your doctor before taking the supplement if you are pregnant or breastfeeding or if you have dementia, liver disease or diabetes.  

What is a safe dose of melatonin? 

If you do decide you want to go ahead and try melatonin as a sleep aide, McCall says short-term use of less than 10 milligrams of melatonin per day is generally safe for healthy adults.  

For those looking to combat jet lag, she recommends taking half of a three-milligram tablet two hours before your destination’s bedtime for a couple of days before your trip to help adjust your sleep schedule. 

“This is especially helpful when traveling from west to east, as many people find it difficult to wake up earlier at their destination,” McCall says. “This small dose should not make you sleepy, but it can help you fall asleep earlier and wake up earlier.”  

One wrinkle: Melatonin is considered a dietary supplement, not a medication, so it is not regulated by the Food and Drug Administration (FDA). This means you aren’t guaranteed to get the amount of melatonin advertised on the bottle (a 2017 study found melatonin content ranged from 83% less to 478% more than advertised). 

To ensure you are taking a safe, intended dose, look for USP (U.S. Pharmacopeia) verified brands, which means the product is free of harmful substances and is labeled with accurate dose information.  

What are signs of melatonin overdose? 

Melatonin poisoning, particularly among children, has increased over the past decade — especially  during the onset of the pandemic. A study of poison control calls in the U.S. found the number of melatonin poisoning–related calls increased six times from 2012 to 2021. Of these calls, more than 4,000 teens and children were hospitalized and two died.  

Signs of melatonin overdose include excessive sleepiness, vomiting and trouble breathing. Other side effects of both low and high doses of melatonin can include headaches, excessive sleepiness, blood pressure changes, gastrointestinal problems, changes in other hormone levels and mood problems, McCall says.  

Keep yourself and your loved ones safe by storing melatonin out of the reach of teens and children. If you suspect you or someone else has taken too much melatonin, seek medical attention immediately.  

How can you get better sleep without taking melatonin? 

If melatonin supplements aren’t the answer to your sleep problems, then what is? 

While decidedly less sexy than a quick-fix supplement, practicing good sleep habits is a tried-and-true way to get more rest. This means going to bed and waking up around the same time each day, limiting your caffeine and alcohol intake, exercising and cutting back on naps. Plus, if you’re looking for ways to treat insomnia, cognitive behavioral therapy for insomnia (CBT-I), is considered the gold standard. 

“This is a sleep retraining program that can effectively reverse the problem using a combination of cognitive tools and behavioral strategies,” McCall says.  

You can also take steps to ensure your natural melatonin kicks in by turning off and dimming lights — including those from electronics — a couple hours before bed. This combination of a darker environment, consistent sleep schedule and healthy habits will help trigger your brain to release melatonin, allowing you to (finally) get some sleep.