Is Melatonin Safe? Plus How to Use it

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We all know what it feels like to get a terrible night’s sleep. We wake up feeling foggy and disoriented. We’re easily frustrated, overwhelmed, or forgetful. Many turn to melatonin to help them get some sleep, but is melatonin safe?

Sure, we’ve all heard of it and likely have taken it at some point, but what exactly is melatonin?

What is Melatonin? 

According to the CDC, one out of three American adults doesn’t get enough sleep on a regular basis. This lack of sleep often has us reaching for sleep aids and other options, like melatonin. 

Melatonin is much like estrogen, progesterone, and testosterone. It’s not just a sleep aid; it’s a powerful hormone. The pineal gland in the brain makes melatonin, but it also comes from other areas of the body. The eyes, skin, and gut all produce it. Melatonin receptors appear on organs and tissues throughout the body. It has a far-reaching impact!

So, what does melatonin do in the body? One of its most important roles is regulating our natural body clock. This is our daily sleep-wake cycle which is tied to darkness and sunlight. Darkness stimulates melatonin release each evening and peaks between 11 pm and 3 am. 

Our nighttime levels are about ten times higher than our daytime levels. Melatonin falls sharply right before daylight and then is barely detectable until nightfall. The rise and fall of melatonin signal our wake and sleep times. Scientists call this our circadian rhythm. 

Melatonin and Cortisol

Cortisol is also involved in this daily rhythm. It’s released with the morning light as melatonin levels fall. Then the pineal gland releases melatonin later in the day in the absence of light – after the sun goes down.

While often referred to as the “stress hormone,” cortisol has an important job. It helps us get out of bed and get going each morning. Melatonin tells the body when it’s time to wind down and go to bed. The problem is that most of us are out of sync.

What Causes Low or Disrupted Melatonin?

As mentioned, our bodies naturally produce melatonin. But that doesn’t mean we have enough. Screentime, caffeine, alcohol, medications, and tobacco can all lower it. Natural aging also lowers melatonin, leading to more frequent sleep disturbances as we get older. 

Working a night shift can also contribute due to light reaching the eyes at the wrong time of day. Since shift workers are working under bright light, natural melatonin production is limited. 

Those living with blindness may also struggle with dysregulated melatonin levels. That’s because they don’t have those light-dark cues to keep their circadian rhythms on track. But this dysregulation can happen to anyone.

When it’s dark, your body produces more melatonin, but when it’s light, the production of melatonin goes down. So, too little natural bright light exposure during the day or too much blue light at night can disrupt melatonin cycles.  

Melatonin for Jet Lag

“Jet lag” is an air travel phenomenon that causes poor sleep quality. It may also lead to fatigue, trouble concentrating, constipation, and other symptoms. Jet lag is more likely to occur when crossing several time zones. The more time zones you cross, the worse it can get.

The recommended dose of melatonin for jet lag ranges from 0.3 to 0.5 mg each evening. Smaller doses may work for some, while others may need more. Higher doses, such as 20 mg pills, are available online. But such high doses aren’t generally recommended or necessary.

Flying east when you lose time may cause worse jet lag than flying west when you gain it back.

  • Eastbound: If you’re traveling east, say, from the U.S. to Europe, take the melatonin after it’s dark outside. Be sure to take it 90 minutes before bedtime in the new time zone. (You can also take it while still on the plane). Then take it for the next four nights in the new time zone, after dark, 90 minutes before bedtime. If still feeling drowsy the day after using this amount, try a little less next time.
  • Westbound: If heading west, like from the U.S. to Australia, a dose isn’t needed the first travel night. You may want to take it for the next four nights in the new time zone. Again, take it after dark, about 90 minutes before bedtime. Melatonin isn’t always necessary for westbound travel.

Other Jet Lag Options

You don’t actually have to take melatonin for jet lag at all. If you give it enough time (usually between 3- 5 days), it typically resolves on its own. But this isn’t always optimal when traveling. After all, if you can get better sleep sooner, you can enjoy your time exploring more!

For some people, melatonin supplements can help them reset their internal clocks. As a result, they get better quality of sleep once they reach their destination. That means they don’t sleep through the bus tour of Rome!

What About Melatonin Supplements?

While melatonin is a natural hormone, the supplement is synthetically made in a lab. It’s the only hormone you can legally get without a prescription in the United States. And in some countries, melatonin is more heavily regulated or prescription only.

The National Center for Complementary and Integrative Health (NCCIH) says melatonin supplements may help certain sleep problems. Those related to circadian disruption may particularly benefit.

Melatonin For Sleep

  • Jet lag – In a meta-analysis of eleven studies, melatonin supplementation reduced symptoms of jet lag.
  • Delayed Sleep Phase Disorder (DSWPD) – In this condition, sleep onset is delayed from a normal bedtime. A person with this condition may not feel sleepy until 3 am. When they do finally drift off, they need to sleep in late. Melatonin supplementation 1 hour before the desired bedtime was helpful for this condition. 
  • Children’s sleep disorders – Children with Attention-Deficit Disorder (ADD) often struggle with sleep. They may have trouble falling asleep or staying asleep. A study published in the Annals of Pharmacology found melatonin was well-tolerated and helpful.
  • Shift work disorder – The use of melatonin helped realign a disrupted circadian rhythm in shift workers. It also helped normalize body weight in a 2021 clinical trial.  
  • Insomnia – Melatonin has helped some people who have trouble sleeping. While study results vary, melatonin may help some people fall asleep faster.
  • Cancer – Scientific research has shown melatonin supplementation may benefit cancer patients. It especially helped those diagnosed with breast or prostate cancer.

Melatonin may also help people who are blind. Because they cannot see, those with blindness miss a key aspect of their biological clock/circadian rhythm. Without this natural clock helping their bodies know daytime from nighttime, their sleep may suffer.

According to The Sleep Doctor™, Michael J. Breus, Ph.D. :

“While melatonin could be considered natural, in most cases it doesn’t come from the earth. There are exceptions of foods that contain melatonin in them, but this is a different type of melatonin than what is produced in your brain.”

Is Melatonin Safe For Adults & Children?

While supplementing with melatonin may seem like an excellent way to get back on track, I’d recommend only using it short-term. Melatonin appears to be safe when used occasionally, but the supplements haven’t been studied for long-term use. So, we currently don’t have any long-term safety data. 

You also shouldn’t take melatonin if pregnant or nursing. After all, melatonin IS a hormone. In a way, it’s hormone therapy, which isn’t something to mess with when pregnant or nursing. If you have a history of hormone issues, you might want to check with your healthcare provider before adding it to your regimen.

Kids are likely better off taking something else, like chamomile for sleep. Because melatonin is a hormone, taking it while still developing may interfere with sexual development. (More on that below). Less invasive remedies include white noise, a weighted blanket, or tart cherry juice gummies. Learn more natural ways to help kids sleep here.

Potential Negatives of Supplemental Melatonin

#1: Supplemental Melatonin May Atrophy The Pineal Gland

Use it or lose it – isn’t that how it goes? It’s certainly the case with muscle tone. You know what happens when you stop exercising for months or years: the muscles atrophy, and you lose what you’ve spent months working to build.

When it comes to hormone producing glands, the same also appears to be true. For example, you may have heard that anabolic steroids (which mimic testosterone) cause testicles to shrink. That’s what happens when you give the body a vacation and don’t expect it to produce on its own.

Every hormonal system in the body has a feedback loop. The testicles normally receive a signal from the brain in the form of two hormones. These are Luteinizing Hormone (LH) and Follicular Stimulating Hormone (FSH). These hormones tell the testicles to make testosterone and sperm, grow, and develop. 

Use it or Lose it

If you add extra testosterone (steroids) into the mix, the LH and FSH will send a message to your brain saying that there’s plenty of testosterone. No need for any more testosterone production. Over time, this can cause the testicles to atrophy from lack of activity. It can be permanent!

The pineal gland, which produces melatonin, may function in the same way. This is according to Dr. David Clark, a functional neurologist in Dallas, Texas. That’s likely why most melatonin supplements come with a warning not to use them for more than 2-3 weeks. 

#2: Melatonin May Affect Fertility

Planning on having a baby? Melatonin doesn’t just help set our circadian rhythm – it also helps govern our reproductive system. In Europe, high doses of melatonin have been tested as a contraceptive.

What exactly is a “high dose”? The study mentioned above used 75 milligrams, which is more than most people would consider taking. Still, Dr. Breus says many commercially available forms have 3-10 times the dosage determined to be effective by the original MIT melatonin research. 

Recent melatonin research indicates it’s probably not effective as a contraceptive. At least, not as effective as the researchers at MIT first believed. But it’s crucial people are aware of that potential side effect. Melatonin supplementation and how it affects sex hormones still isn’t entirely understood.

#3: Melatonin May Affect Sexual Development In Children

Though it now comes in cherry-flavored chewable capsules, melatonin isn’t recommended for children. At least, not by the revered Mayo Clinic. 

According to Mayo Clinic, melatonin “plays a role in the way a person’s body matures sexually.” They also note that melatonin levels impact how the ovaries and testes work. There isn’t enough research yet to know how melatonin supplements impact children’s sexual development.

The National Institutes of Health agree, saying: 

“There is some concern that melatonin might interfere with development during adolescence. Melatonin should only be used in children with a medical need. There isn’t enough evidence to know if melatonin is safe in children when taken by mouth, long-term.”

In other words, we have no idea yet how supplementing this hormone in children might affect their development.

#4: Other Possible Side Effects of Melatonin Use

According to Mayo Clinic, melatonin can also cause daytime sleepiness, dizziness, headaches, abdominal pain, mild anxiety, irritability, confusion, and feelings of depression. You’re more likely to get a melatonin hangover with too high of a dose or if it’s taken too close to bedtime.

  • Thyroid – In animal studies, high melatonin levels have been shown to decrease T3 & T4 (thyroid hormone) uptake. However, that was through melatonin injections, not supplementation.
  • Reduced semen quality in men – Because of its effects on hormones, melatonin used long-term may lead to reduced semen quality in some healthy men. 

If you experience drowsiness the morning after taking melatonin, try taking less. So far, most evidence suggests melatonin is safe for occasional use. 

A critical systematic review found most side effects were minor, temporary, and easily treated. These included problems with fatigue, mood, and brain and body function. Several studies reported symptoms with fertility markers, blood sugar levels, and heart problems.

The researchers went on to say the dosage and when the participants took the melatonin seemed to influence how it was tolerated.

#5: Melatonin May Interact with Medication

Melatonin can decrease the effectiveness of some medications. It may also positively decrease side effects from others. These are some possible melatonin-drug interactions to be aware of:

  • Antidepressant medications
  • Antipsychotic medications
  • Benzodiazepines
  • Beta-blockers
  • Birth control pills
  • Blood pressure medications
  • Blood-thinning medications (anticoagulants)
  • Interleukin-2
  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Steroids and other immunosuppressant medications
  • Tamoxifen

These aren’t inevitable. They’re possible in some people at certain dosages. If you’re concerned about drug interactions, consider ways to increase your melatonin levels naturally.

How To Increase Melatonin Naturally

Before reaching for the bottle of melatonin, consider what you can do to raise it naturally.

  • Blue Light during the day – Daytime blue/white light exposure promotes a normal circadian rhythm of melatonin. This help the body make higher levels at night. I aim for getting 10-15 minutes of sunlight outside first thing in the morning.
  • Red Light at night – Avoiding blue light at night and instead getting light in the red/orange spectrum, is also important. That’s why I wear orange glasses at night. I also have floor lamps with warm-toned lightbulbs set on a timer to come on once the sun sets.
  • Daytime exercise only – Daytime exercise serves as a “zeitgeber” (“time-giver”) to the body. It helps signal the natural body clock that it’s daytime, the time to be active. That also means you don’t want to exercise after dark.
  • High Tryptophan foods – The precursor to melatonin is serotonin. Serotonin is a neurotransmitter made from the amino acid tryptophan. Eating foods high in tryptophan may ultimately help you make more melatonin.
  • Other foods – Several studies note that certain foods contain melatonin as measured by labs. But it’s unclear if they have any positive impact on hormone levels when eaten. Several reviews say no.

Diets rich in fresh produce may contain considerable levels of dietary melatonin. However, the overall effect of dietary consumption nighttime levels later on is very limited. Melatonin production is mostly driven by light and darkness. It also varies by age. declining as we get older.

How Much Melatonin is Optimal? 

For Jet Lag 

Melatonin is considered an effective treatment for jet lag. It can help promote sleep during times when you’d not normally be awake.

Effective starting doses for jet lag range from 0.3 to 0.5 mg of melatonin. If you can’t find a small dose, then you can cut a one-milligram tablet in half. Lower doses may work for some people, while others may need a higher dose, up to 3 to 5 mg. Higher doses may cause more side effects such as headaches, next-day grogginess, or vivid dreams.

For General Use

Always start with the lowest dose. According to a Cochrane review, doses over 5 mg don’t appear to be more effective than lower doses. While much higher doses are available for sale in the U.S., these may result in excessively high melatonin levels.

What I Do

There are mixed opinions on melatonin based on the available evidence. Because it isn’t natural for our bodies to have such high doses, I prefer to err on the side of caution and focus on other natural sleep remedies. I skip melatonin supplements for my kids and for long-term use myself. I save my melatonin for when I’m traveling across time zones.

Here are some ways to help get better sleep without melatonin:

Melatonin Cautions

Here are a few things to keep in mind when taking melatonin supplements:

  • Avoid driving or operating machinery for at least 4 hours after taking melatonin.
  • Avoid using this medication with other prescription medications, over-the-counter drugs, or dietary supplements. Check with your healthcare professional first.
  • Avoid drinking alcohol while on melatonin.
  • Avoid coffee, tea, cola, energy drinks, or other products containing caffeine. They may counteract the effects of melatonin.

Bottom Line on Melatonin Supplements

Short-term use (up to 3 months) of melatonin supplements is generally considered safe and may help you sleep better. It’s widely available in the United States as an over-the-counter medication. You can find it at natural foods stores, pharmacies, and even grocery stores. It comes in a variety of forms and dosages. 

Keep in mind that the Food and Drug Administration (FDA) hasn’t approved it for any use. And because it’s regulated as an OTC supplement, the quality may also lack consistency. For that reason, you’ll want to buy melatonin supplements from a reputable company.

Do you use melatonin? Do you use it regularly or just for jet lag? What has your experience been?

  1. U. S. Centers for Disease Control and Prevention. (February 18, 2016). 1 in 3 adults don’t get enough sleep. CDC Online Newsroom. 
  2. National Center for Complementary and Alternative Medicine. (July 2022). Melatonin: What You Need To Know. NCCIH Health information.
  3. Suni, E. (October 7, 2022). Melatonin: An Overview. Sleep Foundation.
  4. Cipolla-Neto, J., et al. (2022). The Crosstalk between Melatonin and Sex Steroid Hormones. Neuroendocrinology112(2), 115–129.
  5. Breus, M. (February 10, 2011). Melatonin: Not a Magic Bullet for Sleep. WebMD.
  6. Tordjman, S., et al. (2017). Melatonin: Pharmacology, Functions and Therapeutic Benefits. Current neuropharmacology, 15(3), 434–443.
  7. Tortorolo, F., et al. (2015). Is melatonin useful for jet lag? Medwave, 15 Suppl 3, e6343. 
  8. Sletten, T. L., et al. (2018). Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial. PLoS medicine, 15(6), e1002587. 
  9. Bendz, L. M., & Scates, A. C. (2010). Melatonin treatment for insomnia in pediatric patients with attention-deficit/hyperactivity disorder. The Annals of pharmacotherapy, 44(1), 185–191.
  10. Marqueze, E. et al. (2021). Exogenous melatonin decreases circadian misalignment and body weight among early types. Journal of pineal research, 71(2), e12750.
  11. Low, T. et al. (2020). The efficacy of melatonin and melatonin agonists in insomnia – An umbrella review. Journal of psychiatric research, 121, 10–23.
  12.  Talib, W. et al. (2021). Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities. Molecules (Basel, Switzerland), 26(9), 2506.
  13. Memorial Sloan Kettering Cancer Center. (June 7, 2022). Melatonin: Purported Benefits, Side Effects, and More
  14. Silman R. E. (1993). Melatonin: a contraceptive for the nineties. European journal of obstetrics, gynecology, and reproductive biology, 49(1-2), 3–9. 
  15. Thompson, E. A. (2005). Rest easy: MIT study confirms melatonin’s value as sleep aid. MIT News.
  16. Rohr, U. D., & Herold, J. (2002). Melatonin deficiencies in women. Maturitas, 41 Suppl 1, S85–S104.
  17. Bishop, S. (December 7, 2012). Should Children and Teens Use Melatonin as a Sleep Aid? Mayo Clinic News Network.
  18. U.S. National Library of Medicine. (February 15, 2015). Melatonin: MedlinePlus Supplements.
  19. Bauer, B. A. (October 28, 2022). Melatonin side effects: What are the risks? Mayo Clinic.
  20. Rom-Bugoslavskaia, E. S., & Shcherbakova, V. S. (1986). Sezonnye osobennosti vliianiia melatonina na funktsiiu shchitovidno? zhelezy [Seasonal characteristics of the effect of melatonin on thyroid function]. Biulleten’ eksperimental’noi biologii i meditsiny, 101(3), 268–269.
  21. Luboshitzky, R., Shen-Orr, Z., Nave, R., Lavi, S., & Lavie, P. (2002). Melatonin administration alters semen quality in healthy men. Journal of andrology, 23(4), 572–578.
  22. Foley, H. M., & Steel, A. E. (2019). Adverse events associated with oral administration of melatonin: A critical systematic review of clinical evidence. Complementary therapies in medicine, 42, 65–81.
  23. Buxton, O. et al. (1997). Acute and delayed effects of exercise on human melatonin secretion. Journal of biological rhythms, 12(6), 568–574.
  24. Peuhkuri, K., et al.(2012). Dietary factors and fluctuating levels of melatonin. Food & nutrition research, 56, 10.3402/fnr.v56i0.17252. 
  25. Herxheimer, A., & Petrie KJ. (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD001520. 
  26. Kennaway D. J. (2017). Are the proposed benefits of melatonin-rich foods too hard to swallow?. Critical reviews in food science and nutrition, 57(5), 958–962.

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


5 responses to “Is Melatonin Safe? Plus How to Use it”

  1. Lisa Brinker Avatar
    Lisa Brinker

    I take it once in a while but I find that I sleep heavily at first and then I’m wide awake around 5 hours later (@3 am). I’m 57 and I heard that your melatonin decreases as you age. I also read that it’s on the protocol for when you have Covid. I often recommend it to my husband when he is on business travel but he’s wary of trying it. I’m still on the fence of recommending it to my 93 yo mom. Would it be a bad thing at that age to take it regularly?

  2. Julia Crouch Avatar
    Julia Crouch

    Hi Katie!
    I live in Canada and we are able to buy melatonin without prescription. It’s in most grocery stores and health food stores.

    For what it’s worth I’ve also seen in on shelves while travelling in Europe, so I don’t think it’s as heavily regulated as indicates in your article.

    Great info otherwise!
    Thanks for doing what you do.


  3. Susana Rodrigues Avatar
    Susana Rodrigues

    Hey great article. Just want to say that I live in Portugal and we dont need a prescription to buy melatonin here aswell. Actually its kinda scary because the kids channels are always playing melatonin adds promoting it for kids.

  4. Nerissa Bysterveld Avatar
    Nerissa Bysterveld

    I live in Canada and just picked up melatonin today off the shelf. We do not need a prescription to get it here.

  5. Lisa Duncan Avatar
    Lisa Duncan

    I use 3mg melatonin most nights, before bed, to increase the quality of my sleep, and to help fall asleep. It is an OTC here in Canada; I’m aware of it sold up to 9 mg doses. I have read several studies about it helping detox pathways during sleep (can’t remember a the specifics now, sorry). My son takes it, as he has trouble sleeping, and without it, tends to wake up at night and can’t fall asleep again (ADHD). I didn’t realize it could impact his development, so we’ll try a break and support him other ways, while I research further; thank you 🙂

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