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Asking For A Friend: Does Melatonin Actually Give You Crazy Dreams?

Julia Guerra
Author: Expert reviewer:
May 27, 2022
Julia Guerra
Health Writer
By Julia Guerra
Health Writer
Julia Guerra is a health and wellness writer reporting for mindbodygreen, Elite Daily, and INSIDER.
Ashley Jordan Ferira, Ph.D., RDN
Expert review by
Ashley Jordan Ferira, Ph.D., RDN
mbg Vice President of Scientific Affairs
Ashley Jordan Ferira, Ph.D., RDN is Vice President of Scientific Affairs at mindbodygreen. She received her bachelor's degree in Biological Basis of Behavior from the University of Pennsylvania and Ph.D. in Foods and Nutrition from the University of Georgia.
May 27, 2022
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While dreams remain a scientific mystery—why we have them, the psychology behind them—one thing's for sure about these nightly visions: Sometimes they're sweet, sometimes they're terrifying, and other times they're just plain weird. Many believe that day-to-day details influence these occasionally outrageous storylines and that something as simple as taking melatonin can give you crazy dreams. 

But is this melatonin side effect actually backed by science? Here's what the research says.

What is melatonin?

Melatonin, also known as the sleep hormone, is produced in the pineal gland of the brain1 and, according to sleep expert Jacob Teitelbaum, M.D., its primary function is to signal to the body what time of day it is and set our circadian rhythm.

"This is critical for many functions," Teitelbaum tells mbg, but, most importantly, for nudging us to sleep at nighttime. When the sun goes down and your space gets dark, that's when melatonin can kick in and tell the body that it's time for bed.

So, how does melatonin affect sleep?

To put it simply, neuroscientist Matthew Walker, Ph.D., once likened melatonin to the official at an Olympic race that fires off the starting gun. Walker tells NPR that melatonin "organizes the great sleep race and then begins the race" by signaling to the rest of the body that it's time to prepare for sleep.

In other words, melatonin doesn't induce sleep on its own; it gives all systems the go-ahead to begin the transition from wake to sleep.

What's interesting is that most people associate melatonin with sleepiness, when the true parallel is between melatonin and a clock. According to Walker, those who feel like taking melatonin supplements makes them sleepy are actually experiencing a placebo effect. "There are a whole set of different chemicals and brain mechanisms that actually generate sleep and get you into sleep. Melatonin simply times when sleep is going to occur, not the generation of sleep itself," he tells the outlet. 

This is one of a few reasons why other, non-melatonin supplements are typically more effective (not to mention, safer) for nightly sleep support.

How does melatonin affect your dreams?

According to Catherine Darley, N.D., of The Institute of Naturopathic Sleep Medicine, Inc., there is some research2 to show that by affecting the circadian rhythm, melatonin promotes more time in REM sleep, which is the sleep stage most associated with dreaming. As such, Darley tells mbg the body's natural stores of the hormone can create "a big change in our dream experience" by potentially evoking more vivid dreams.

That being said, the jury's still out on whether or not taking a melatonin supplement gives you crazy dreams. According to Darley, there isn't enough solid research to suggest that taking melatonin would lead someone to have more odd dreams than usual.

However, if you're taking melatonin to get back on track after a period of suboptimal sleep, Medina tells mbg it is possible to have some weird dreams when you start sleeping more through the night. It's also possible that someone taking melatonin would experience odd dreams because melatonin can lead to overactivation in different parts of the brain3

"There are melatonin receptors all over the brain in regions like the cortex, thalamus, substantia nigra, nucleus accumbens, amygdala, hippocampus, cerebellum, and your eyes," Medina explains. "These are areas that are heavily involved in learning, memory, processing fearful events and threatening stimuli, stress relations, and cognitive executive function. So, when taking an amount of melatonin that is larger than what the body is used to, it is not surprising why these areas are overactive with the amount of melatonin that is available on the market."

Indeed, recent research shows that over the last 20 years, taking more than 5 milligrams of melatonin per day (much higher than the typical recommended dosage of 0.5 milligram, which is more closely aligned with human physiological levels of the hormone) has become more common in the U.S. This raises some safety concerns, as experts agree that taking high doses of any hormone—especially one that is as widespread as melatonin—can throw off your body's natural hormone production.

So while the science is limited on the direct link between melatonin and dreams, including the bad ones, there's no denying that many people report having nightmares after taking this sleep aid, so more science is certainly warranted to suss out this apparent association or actual phenomenon.

The takeaway. 

Though melatonin is a hormone that sets your circadian rhythm and gives your body's internal systems the green light to start getting ready for bed, it has little effect on your sleep quality or the content of your dreams. If you're waking up in the morning remembering bits and pieces of weird dreams, chances are it has less to do with the melatonin and is more likely a response to something that happened yesterday, like what you ate for dinner.

Julia Guerra author page.
Julia Guerra
Health Writer

Julia Guerra is a health and wellness writer reporting for mindbodygreen, Elite Daily, and INSIDER. Formerly the beauty editor for, she's contributed to Women's Health, Cosmopolitan, PopSugar, and more. A book worm and fitness enthusiast, her happiest moments are spent with her husband, family, sipping tea, and cuddling with her Tabby cat, Aria.