How Much Melatonin Is Too Much? Here’s the Ultimate Guide for Safe Use

Taking melatonin for sleep is becoming more common, but how much melatonin is too much? Sleep experts weigh in.

Sleep is absolutely crucial for achieving optimal health and preventing chronic disease, but many of us struggle to snag enough shut-eye on a regular basis. In fact, the Centers for Disease Control (CDC) estimates that around one third of Americans fall short of the recommended seven to nine hours per night, and researchers have noted an increase in sleep-related issues since the beginning of the COVID-19 pandemic (triggered, unsurprisingly, by increased psychological distress). But instead of popping prescription sleep drugs like Ambien—which can have a slew of troubling side effects including hallucinations—people are increasingly turning to melatonin supplements

Melatonin is a naturally occurring hormone in the body, informally dubbed the “sleep hormone” for its ability to help adjust your internal “body clock” and induce sleepiness. While everyone’s brain naturally produces melatonin in response to darkness or reduced light, it’s also sold in supplemental form as a sleep aid. Even before the pandemic, melatonin use was on the rise—survey data of 55,000 U.S. adults found that melatonin usage jumped from 0.4 to 2.1 percent (a five-fold increase) from 1999 to 2018. The pandemic only fueled this trend, with consumers spending 42.6 percent more money on melatonin products in 2020 than the prior year, according to data from Nielsen. 

The problem? Many people are taking too much melatonin, taking it at the wrong time, or taking it for the wrong sleep issues. 

While melatonin is not a sleep cure-all, it can benefit some people when used correctly. Here, we break down must-know facts about melatonin—including how much melatonin is too much—so you can use it safely and get the greatest benefit.  

What is Melatonin and How Does it Work?

Melatonin is a hormone naturally produced in the brain’s pineal gland that helps regulate your body’s 24-hour circadian clock, which dictates your sleep-wake cycle (or when you fall asleep and wake up each day). When the sun begins to set, a special group of neurons in your brain’s hypothalamus called the suprachiasmatic nucleus (SCN) senses this waning light and prompts the pineal gland to secrete melatonin, which essentially tells your body that it’s nighttime. As melatonin rises, levels of cortisol—a stimulating daytime hormone—fall. 

While melatonin doesn’t make you fall asleep, exactly, it does lull the body into a state of quiet wakefulness in the evening that promotes sleep, according to Luis F. Buenaver, PhD, CBSM, assistant professor of psychiatry and behavioral sciences at Johns Hopkins Medicine. In the morning, on the other hand, the SCN senses daylight and subsequently suppresses melatonin secretion, and increases cortisol, so you feel more alert and can start your day.

But several things can mess with this process. Factors such as light exposure (from laptops, smartphones, and TVs), jet lag after a trip, and even getting older can interfere with appropriate melatonin secretion and prime you for poor sleep—hence why many people turn to supplements. 

too much melatonin

What Can Melatonin Supplements Be Used for?

Melatonin has been shown in clinical studies to be effective at decreasing the time it takes to fall asleep, increase total sleep duration, and improve sleep quality.

Melatonin’s ability to adjust your circadian clock makes it quite useful for short-term use in some key scenarios: makes it quite useful for short-term use in some key scenarios: delayed sleep phase syndrome (DSPS) and jet lag, says James Rowley, MD, a board member of the American Academy of Sleep Medicine (AASM) and professor at Wayne State University School of Medicine. Melatonin may also help reset your circadian clock if you work the overnight shift, so you can get quality sleep during the day. 

Melatonin and DSPS 

With delayed sleep phase syndrome, a person’s body clock tells them to stay up later and wake up later than they should—usually by at least two hours. Sleep quality and total sleep time may still be healthy, but the entire sleep cycle is shifted later. For example, someone with DSPS may naturally be primed to fall asleep at 2 a.m. and wake at 10 a.m., making it difficult to get up for work or school. For people with these extreme night-owl tendencies, research suggests that taking melatonin one-and-a-half to six hours before their desired bedtime may “help shift their circadian rhythms such that they can fall asleep at a more ‘regular’ time,” says Dr. Rowley. This could mean taking melatonin at 8 p.m if you want to fall asleep by 11 p.m. 

Melatonin for Jet Lag 

The jet lag you experience when you travel across several time zones (think: California to New York) occurs because your circadian rhythm hasn’t had time to adapt to your current location. For a few days, your sleep-wake cycle remains delayed and you struggle to fall asleep by an appropriate local bedtime, which can lead to daytime grogginess. In these instances, melatonin can help reset your circadian rhythm faster and reduce these symptoms when timed appropriately, according to the AASM. One research review found melatonin, taken close to the target bedtime of the destination, effectively reduced jet lag when people crossed multiple time zones. Consider taking melatonin one hour before your desired destination bedtime on your travel day and for several days after you land until you’ve acclimated. If you’re crossing seven or more time zones, try starting this process one to three days before your trip. 

Melatonin and Overnight Shift Work 

People who work the overnight shift often struggle with sleep because they’re operating counter to their body’s natural circadian rhythm. The idea behind taking melatonin is that it could help reset your body clock and put you in a sleep-ready state in the morning, as opposed to evening. Studies suggest that taking melatonin after an overnight shift and at least 30 minutes before daytime sleep improves daytime sleep, but not necessarily nighttime alertness. Still, the AASM recommends melatonin to promote daytime sleep among shift workers.   

Melatonin for Sleeplessness 

But what about general difficulty falling asleep and staying asleep? This is where the science gets interesting. Difficulty falling asleep, staying asleep, or both, are the main reasons people take melatonin. In a meta-analysis, taking melatonin was found to help people fall asleep faster, sleep longer and improve overall sleep quality. The results also did not dissipate with continued melatonin use. If you suffer from chronic insomnia (occurring at least three nights a week for three months or more) it is best to speak with your doctor or health care provider for a solution.

Additional research supports the benefits of taking melatonin before bed- with a study showing 3 mg of melatonin taken 30 minutes before bedtime helped people fall asleep faster.  (It’s worth noting that HUM’s VP of scientific affairs and education, Jennifer Martin-Biggers, PhD, MS, RD, recommends a melatonin-containing product like HUM’s Beauty zzZz or Beauty zzZz Gummies to help you fall asleep, but says the ingredients in HUM’s Mighty Night have stronger evidence for helping you stay asleep than melatonin.)

Melatonin Dosage: Taking the Right Amount

With melatonin, an appropriate dose is essential for reaping the benefits and avoiding unpleasant side effects. Here’s what you should know.

How Much Melatonin Can You Take?

Melatonin supplements can generally be found online and in drug stores in doses ranging from 1 mg to 10 mg or higher. However, no official dosing or timing guidelines have been set for any condition, says Dr. Rowley. The general rule among sleep experts, though, is that you should really be using the lowest effective dose, which can vary based on your individual needs. So where do you begin, and what’s a good place to cap your melatonin intake? 

Several studies suggest melatonin may offer benefits for the conditions mentioned above with a relatively low risk of side effects at doses ranging from 0.5 mg to 5 mg. (For example, sleep doctors often recommend anywhere from 3 mg to 5 mg for DSPS, says Dr. Rowley.)

And while melatonin production declines with age, that doesn’t mean older adults always need more. In fact, adults over age 55 should make a special point to start with the lowest dose of melatonin possible, since research suggests they are more sensitive to its effects. 

melatonin dosage

How Much Melatonin is Too Much?

Taking more than 10 mg of melatonin per day is generally not recommended and may come with a greater risk of side effects—and research suggests these higher doses have actually become more common in recent years. 

Taking too much melatonin could actually disrupt your circadian rhythm and make sleep worse. While some people have voiced concerns about long term use of melatonin, there is no research to support any desensitization or problems with long term intake in adults.  Since appropriate dosing is so important, you want to make sure you’re choosing a reputable brand that actually contains the amount of melatonin listed on the label, like HUM’s Beauty zzZz, which contains a safe and clinically effective dose of 3 mg. Research has found that some low-quality supplement brands may contain anywhere from 83 percent less melatonin than the amount on the label or 478 percent more. HUM Nutrition maintains checks throughout the manufacturing process to ensure the amount on the label is what consumers are getting.

Can You Overdose on Melatonin?

Melatonin won’t cause a lethal overdose in adults. “You can’t overdose, but taking too much melatonin could result in side effects like dizziness, headache, confusion, drowsiness, and nausea or vomiting,” says Dr. Rowley. This unpleasant combination of symptoms has unofficially been dubbed the “melatonin hangover.” If you experience these, try a lower dose. 

You should be extra cautious when giving melatonin to children and always consult their pediatrician first. Per the CDC, unintentional melatonin ingestion among kids is also on the rise, which can have health consequences—so store those supplements safely! 

How Long Does it Take for Melatonin to Work?

Melatonin reaches peak levels in the body about an hour after taking a typical dose of 1 to 5 mg. Experts often recommend timing melatonin intake at least 20 minutes to one hour before bedtime—not right at bedtime—so it’s sending your body those “time for bed” signals as you hit the sheets. If you are experiencing chronic sleeplessness or think you may have a condition like DSPS, talk to your physician about what may be best for you.

Man with jet lag looking out of hotel window

When to Not Take Melatonin

Melatonin isn’t for everyone. Here are some factors to consider when deciding whether or not to take (or continue taking) this popular sleep supplement. Talk to your doctor or a sleep specialist for more guidance on any of these situations. 

Melatonin and Alcohol

It’s not advised to mix your melatonin supplement with alcohol for a couple of reasons. For one, alcohol disrupts the body’s sleep-wake cycle, while the goal of melatonin is often to promote a healthy sleep-wake cycle—so drinking may interfere with melatonin’s intended function. Additionally, both alcohol and melatonin can promote drowsiness, which could potentially result in severe sleepiness that impairs your ability to drive or perform other tasks. 

Melatonin and Pregnancy

Avoid melatonin if you’re pregnant or breastfeeding. There’s not enough data on melatonin’s safety for mom and baby in these situations, and small amounts of melatonin can pass into breast milk. Some researchers believe that low doses of melatonin taken over a short period of time may be safe while breastfeeding, but more research is needed—so hold off for now. 

The Takeaway

Melatonin can be a useful tool to adjust your internal body clock—and this can potentially help you fall asleep earlier, curb jet lag symptoms, get quality sleep regardless of your work schedule, and alleviate normal sleeplessness. Keep in mind, appropriate dosage and timing is key for reaping the benefits of melatonin. If you’re interested in trying melatonin, look for a high-quality supplement that offers a safe dose (somewhere between 0.5 and 5 mg per day) for your specific needs. And remember, since there are a lot of factors at play, it’s never a bad idea to consult a doctor or sleep specialist to help guide this process.

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