Melatonin and Dreams: A Sleep Doctor Explains the Connection

If you're among the many people taking melatonin to help you sleep, you might know that melatonin's side effects can sometimes include headaches and nausea. But can melatonin cause bad dreams, too?

If you've noticed an uptick in weird, vivid or intense dreams when taking melatonin, it's likely not a coincidence, says Carleara Weiss, PhD, RN, a behavioral sleep medicine and circadian rhythm specialist and a sleep science advisor for Aeroflow Sleep. There's a strong link between melatonin and dreams, although researchers are still trying to fully understand it.

Here, we'll look at what melatonin does in the body, why you might have bad dreams with melatonin and what you can do to tame this side effect and get better shut-eye.

Melatonin is a hormone produced in the brain that plays a role in a variety of body processes, including regulating metabolism and menstruation. But it's best known for its effect on the sleep-wake cycle (aka, your circadian rhythm).

"Melatonin is mostly known for its effects on sleep because melatonin production is linked to the biological clock, our perception of the time of the day and sleep time," Weiss says. "We produce melatonin in response to dim or darkness, telling our body to prepare for bedtime."

As a supplement, melatonin is often used as a natural sleep aid to help ease certain types of insomnia, per Mount Sinai.

"Taking a melatonin supplement reinforces to our body that sleep time is approaching," Weiss says. "Therefore, it supports sleep onset. People with sleep and circadian rhythm disorders such as jet lag, shift workers or people with blindness can benefit from taking melatonin at a specific time to resynchronize their sleep-wake cycle."

It sure can, according to Weiss, although we're still figuring out exactly why this happens.

"Some studies indicate two mechanisms to justify this 'side effect' of melatonin," she says. "First, melatonin may increase the duration of REM sleep, where most dreams occur. Therefore, a person may have more dreams or experience nightmares while spending more time in this sleep stage."

Makes sense. Basically, more time spent dreaming increases your chances of having bad dreams.

"Second, melatonin impacts vasotocin release," Weiss says. "Vasotocin is a protein that regulates REM sleep. Higher levels of vasotocin have been linked to vivid dreams."

But keep in mind other things can cause vivid dreams as well, including:

• Sleep deprivation
• Anxiety or stress
• Hormone shifts, such as during pregnancy and postpartum, or right before your period starts
• Certain medications, such as antidepressants and blood pressure drugs
• Sleep conditions like narcolepsy

"Typically, melatonin's side effects, including nightmares and vivid dreams, are linked to high doses," Weiss says.

The best way to avoid them is to follow the recommended dose: That's 0.5 to 5 milligrams for adults, Weiss says. The melatonin dosage for kids is lower, with the recommendation being 0.5 to 1 milligram (so long as the child's pediatrician has signed off).

To make sure you're getting the correct dose, it's important to choose a high-quality melatonin supplement. Dietary supplements like melatonin are only loosely regulated by the FDA, so be selective about the product you buy. "Finding a reputable source that contains melatonin without combining it with other hormones or drugs is critical," Weiss says.

She recommends the following:

• ‌Look for a supplement that's been third-party tested for quality‌. These brands will usually have a seal on their label from the likes of USP or NSF. This means the product has been tested to ensure it contains the ingredients it claims in the stated amounts without any hidden extras.
• ‌Check the list of ingredients to make sure it only contains melatonin‌. Prioritize brands with ingredient transparency, meaning they list everything in the product on the label.

It's worth noting that melatonin isn't meant to be taken for more than a month or two at a time, per Johns Hopkins Medicine. "Melatonin is not the first recommendation to treat insomnia and should not be used as a long-term solution for sleep," Weiss says.

Melatonin supplements also aren't for everyone. According to Weiss, you should avoid the supplement if you:

• Are pregnant or breastfeeding
• Have a bleeding or seizure disorder
• Take hormonal birth control
• Take other medications, including those for high blood pressure and diabetes

Talk to your doctor before taking a melatonin supplement, especially if you're currently on medication or taking other supplements.

As Weiss mentioned, melatonin isn't the first thing you should turn to when you have trouble nodding off. Instead, sleep experts generally recommend following good sleep hygiene practices, including the following:

• ‌Keep your bedroom cool, dark and quiet‌. If that's a challenge, consider investing in accessories that can help block out distractions while you sleep, such as ear plugs or an eye mask.
• ‌Limit or avoid screen time‌ in the hour or two before bed.
• ‌Eat your last meal at least a couple hours before bedtime‌, and avoid caffeine past the early afternoon. Try to avoid alcohol before bed, too.
• ‌Get bright light early in the day‌ and get some exercise during daylight hours.
• ‌Stick to a sleep schedule‌, meaning you go to bed and wake up at the same times every day, including on the weekends.
• ‌Create a relaxing wind-down routine‌ before bed that involves soothing activities like reading, journaling, meditating or taking a warm shower or bath.

If you've tried the above sleep hygiene tweaks but are still struggling to get consistent, quality shut-eye, it may be worth booking an appointment with a sleep medicine specialist to rule out underlying conditions and get a more personalized treatment plan.

Likewise, if you find you often turn to melatonin for help with sleep, talk to a specialist about other approaches you can try for better rest.