How Safe Is It To Take Melatonin Every Night?

Everything you need to know about taking melatonin supplements regularly

Finding it hard to fall asleep or stay asleep can be frustrating, especially if it happens on a regular basis. To get much-needed rest, many people turn to the sleep supplement melatonin, which is a synthetic version of the natural melatonin your body makes to help induce sleepiness.

But is melatonin safe to take every day? Here's what sleep experts what you to know about melatonin and whether regular daily use is risky.

Dietary supplements are minimally regulated by the FDA and may or may not be suitable for you. The effects of supplements vary from person to person and depend on many variables, including type, dosage, frequency of use, and interactions with current medications. Please speak with your healthcare provider or pharmacist before starting any supplements.

What Is Melatonin?

Melatonin is a hormone made by your body in the pineal gland, which is just above the center of the brain. Although melatonin is said to play a role in other body system regulations (e.g., bone metabolism, fertility), the hormone is primarily known for regulating your internal clocks' sleep-wake cycle.

"Melatonin gets released when the sun goes down," Beth Malow, MD, a professor in the department of neurology and pediatrics and director of the sleep disorders division at Vanderbilt University Medical Center, told Health. "It makes us drowsy—about two hours after melatonin starts getting released, we are ready to go to sleep."

In the morning when the sun comes up again (or you're exposed to bright light), melatonin levels fall, cueing your internal clock that it's time to wake. However, it is also possible for some individuals to have low levels of melatonin. Those low levels can affect their quantity or quality of sleep, resulting in their turn to melatonin supplements in order to get better sleep.

What Are Melatonin Supplements?

The brain normally makes only a very small amount of melatonin—around 0.2 milligrams, Brandon Peters-Mathews, MD, a sleep medicine specialist at Virginia Mason Medical Center in Seattle, told Health.

For some people, that might not be enough to help them get the rest they need. So melatonin supplements, which typically contain higher doses than the amount your body naturally releases, can be useful to treat sleep disorders and insomnia.

"Supplemental melatonin allows us to get drowsy and ready for sleep," said Dr. Malow. "In addition, melatonin can be calming and help us 'turn our brains off.'"

Research backs this up, showing that melatonin supplements can help individuals dealing with conditions such as:

  • Delayed sleep phase wake disorder (DSP)
  • Jet lag
  • Pre-surgery anxiety
  • Some sleep disorders in children

Melatonin supplements can be taken orally, but they are also available in the form of creams, gargles, and gels. Additionally, a melatonin supplement may be slow- or fast-release.

Additionally, melatonin is a prescription medication in Europe. However, in the US, it qualifies as a dietary supplement. That means it's available over the counter without a prescription at drugstores and health-nutrition retail outlets. Also, the U.S. Food and Drug Administration (FDA) does not regulate melatonin very strictly.

Furthermore, not all brands of melatonin are the same. Researchers of a February 2017 Journal of Clinical Sleep Medicine study analyzed 31 melatonin supplements to determine how much melatonin and serotonin (a neurotransmitter mostly known for its role in mood regulation) were in the products.

They found that the melatonin content across all of the supplements ranged from 83% less to 478% more than the content listed on the label. Additionally, the majority of the supplements included less than the claimed amount on the label—with 26% of the supplements containing serotonin.

Therefore, it's important to read the label and make sure you are getting pure melatonin and not melatonin mixed with other substances, warned Dr. Malow.

What Are the Side Effects of Melatonin?

Dr. Peters-Mathews recommended sticking to lower doses (1 to 3 milligrams per nightly dose) of melatonin to prevent unwanted side effects, which typically include increased dreaming, nightmares, or morning sleepiness.

Other general side effects of the short-term use of melatonin are:

However, side effects arising from prolonged use of melatonin are "unclear." If you are bothered by these side effects, you should stop taking melatonin and speak to a healthcare provider about alternatives.

So, Is It Safe To Take Melatonin Every Day—And Is It Considered Safe for Everyone?

Both Dr. Peters-Mathews and Dr. Malow said they believe melatonin is generally safe to take every night, but large studies are needed to determine whether it's effective and safe for all forms of insomnia and particularly for long-term use.

"Melatonin is used safely by most people for years," said Dr. Peters-Mathews. However, the most common time period for daily use of melatonin is up to six months for adults and up to three months for children.

Of note, adults should be cautious about child and adolescent consumption of melatonin, as there is a risk of melatonin poisoning if a child or adolescent ingests too much melatonin.

Melatonin isn't suitable for everyone. You shouldn't take melatonin at all if you:

  • Are pregnant or breastfeeding
  • Have depression, a bleeding disorder, or a seizure disorder
  • Have been a transplant recipient

Further, if you have diabetes or high blood pressure, talk to a healthcare provider before taking melatonin supplements.

And if you are on any medications or taking any herbs and other supplements, check with your physician to make sure melatonin won't make them less effective or cause more side effects. There are a number of medicines, herbs, and supplements that may interact with melatonin supplements.

What if I Can't Take Melatonin or It Doesn't Work for Me?

If melatonin isn't helping with sleep after a week or two of nightly use, Dr. Malow recommended checking in with a healthcare provider about other options that may help with your individual case of sleeping difficulties.

Still, whether or not you take melatonin, there are many ways to create optimal conditions for a good night's sleep. Keep the lights low before bed to cue your body to relax, and if you watch television in the evening, make sure you're at least six feet away from the screen, as the blue light emitted from the television can keep you from nodding off.

"Also, make sure you are taking a wider behavioral approach, including limiting caffeine after early afternoon, limiting alcohol, and turning screens off at least 30 minutes before bedtime," said Dr. Malow.

The Centers for Disease Control and Prevention (CDC) also recommends having a consistent bedtime and wake-up time every day of the week—even on weekends.

A Quick Review

Melatonin is made naturally in the body, but it can also be taken as a supplement to help with sleep. Melatonin is generally safe to take, but it can have side effects and shouldn't be used by everyone.

If you're having trouble with sleep and can't take melatonin or it doesn't work, you can do things like work on improving your sleep schedule and sleep environment. Using those and other practices may help you easily drift off to get better sleep—without having to rely on melatonin supplements all the time.

Was this page helpful?
5 Sources uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ferlazzo N, Andolina G, Cannata A, et al. Is melatonin the cornucopia of the 21st century? Antioxidants. 2020;9(11):1088. doi:10.3390/antiox9111088

  2. MedlinePlus. Melatonin.

  3. National Center for Complementary and Integrative Health. Melatonin: what you need to know.

  4. Erland LA, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin contentJ Clin Sleep Med. 2017;13(2):275-281. Published 2017 Feb 15. doi:10.5664/jcsm.6462

  5. Centers for Disease Control and Prevention. Tips for better sleep.

Related Articles