Melatonin: Everything You Should Know

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If you’ve been struggling with getting to sleep or staying asleep, you may have heard about melatonin and wondered about its effects and how safe it is. Melatonin is a well-known hormone and sleep aid, but there’s a lot to uncover on this topic.

In this guide we’ll talk about what melatonin is, how it works, the recommended dosages, side effects, and other ways to fall asleep that don’t involve melatonin. For some people and in certain circumstances, melatonin could prove helpful, but it’s important to find out if it’s right for you.

What Is Melatonin?

Melatonin is a hormone produced in the pineal gland1, a small, pea-sized gland in the brain. The pineal gland’s primary role is to receive information about the state of light or darkness in your environment and then produce and secrete melatonin accordingly. 

When your brain senses it is dark, it secretes melatonin. This generally happens about two hours before going to sleep. Conversely, melatonin production2 is impeded by bright lights, including sunlight, cell phones, televisions, computers, and indoor lights.This hormone is vital to your body’s natural circadian rhythms (your 24-hour internal clock) and sleep. 

A lesser-known function of melatonin is its role in puberty. According to a 2019 study3, melatonin is produced in larger quantities in children before puberty. On average, sometime between the age of 8 and 13 in females and 9 and 14 in males, the body’s natural levels of melatonin decline sharply, which is believed to play a vital role in triggering the onset of puberty. You may be wondering how melatonin affects children around this age, and we will talk more about that in an upcoming section. 

Melatonin supplements can be made from animals or microorganisms, but in general, they are made synthetically. As mentioned, everybody naturally produces the hormone melatonin, but for some people, adding supplementary melatonin can be useful. 

Supplements & Dosage

If you’re interested in trying out melatonin supplements, you’ll have to decide which type you want to take. Melatonin supplements come in several different forms4: capsules, tablets, liquid, gummies, and even patches. 

The benefits of taking melatonin in pill form are they have a longer shelf life, they are tasteless, and tablets are relatively easy to divide (in case you want to split the dose in half.) The only real drawback to melatonin in pill form is if you have difficulty swallowing pills. 

Melatonin gummies are another option for taking melatonin orally if you don’t like or have difficulty taking pills. In fact, gummies are often sold as melatonin supplements for children since they taste good and are easier to swallow. Just be sure you’re not treating them like candy and exceeding the recommended dose.

Conversely, liquid melatonin doesn’t always taste great, but it’s a good option for those looking for melatonin that’s quickly absorbed and easy to swallow. This form is usually a bit more expensive, though, so keep that in mind. 

These three forms are the most widely used, and there really isn’t one that is recommended more than others by doctors. Capsules and tablets have a longer shelf life, but liquids and gummies may be easier for some people to take and act faster. 

For Adults

Melatonin is not a “more is better” sort of supplement. In fact, people who take too much melatonin report an inverse effect: not being able to sleep as well, having headaches and nightmares, and waking up groggy the next day.4

Doctors recommend .0.3 mg to 5 milligrams (mg)5 for adults, noting that lower doses typically work just as well as higher doses. This might sound like a low dose, considering many melatonin supplements are sold in 5 mg, 6 mg, or even 10 mg. To put this into perspective, though, consider that your body naturally produces only 10-80 micrograms6 of melatonin per night. That’s a little less than .10 mg. So a dose of .5 mg is already about five times more than your body naturally produces, and a dose of 10 mg is up to 100 times more than your body would naturally produce. 

Our bodies naturally produce less melatonin7 as we get older, so older adults might think supplementing with more would be better. On the contrary, it seems that older adults (55 and up) tend to be more sensitive to melatonin’s effects and can experience more grogginess the following day at high doses. Researchers recommend older adults take melatonin at lower doses (around .1 mg), to not disrupt their circadian rhythms and cause daytime drowsiness. This supplement is not recommended for those with dementia.7

The FDA doesn't regulate supplements like melatonin because they are generally presumed safe. Unfortunately, this means the actual concentration of melatonin in your supplements may not be what it says on the label. One study analyzed 31 melatonin supplements and found that actual melatonin content ranged from -83 percent to +478 percent of the labeled content4

One way to ensure you’re getting what it says on the label is to look for melatonin supplements approved by the United States Pharmacopeia, an independent non-profit organization. Look for the words “USP verified” when purchasing melatonin supplements. 

For Kids

Short-term use of melatonin in small doses appears to be well tolerated and safe for most kids, though parents should be sure to consult with their child’s doctor before giving them anything new. 

As with adults, experts recommend that children start with the lowest possible dosage. They go on to say that most kids will respond to 0.5 mg or 1 mg8 of melatonin taken 30-90 minutes before going to bed. However, kids shouldn’t take any more than 3-6 mg. Experts also suggest that melatonin could help children with autism or attention-deficit hyperactivity disorder (ADHD) but that a doctor should be consulted and monitor the child taking it.8

Keep in mind, though, that for kids between the ages of 8 and 14, there is some evidence to suggest melatonin supplements might affect the onset of puberty. This is because the hormone melatonin is vital in the onset of puberty in both males and females. 

In younger children, melatonin is produced9 in much higher quantities. When the production of melatonin drops off significantly, puberty is triggered. If you continue to supplement with melatonin during this time, some scientists3 believe the decrease in melatonin that triggers puberty could be delayed, though more evidence is needed. 

How Long Does Melatonin Last?

Luckily, melatonin is not a supplement that you’ll need to build up in your system for some time before it starts working. This means you can take it 1 – 2 hours before you plan on going to bed and you should feel the effects within that time. Sometime between 4 and 8 hours10 after you take melatonin, your melatonin levels will return to their normal basal concentrations, or, your normal baseline. 

For some, this means melatonin helps get them to sleep but is not so helpful in keeping them asleep. If this is the case for you, you might try taking a “prolonged release” melatonin supplement, which delivers the melatonin over an extended period of time rather than all at once. 

At low doses (around 3 mg or less), most people do not report daytime grogginess after taking melatonin. If you do experience this, you might be taking a dose that is too high for you, and you can try lowering it. Prolonged-release melatonin might also cause more grogginess the next day, so if you’re experiencing this with these types of supplements, try switching to a regular, immediate-release formula. 

Boy Sleeping Peacefully Thanks to Melatonin Illustration

Melatonin Side Effects

Melatonin is generally a safe, short-term solution for sleep problems and doesn’t typically cause the sort of side effects common to most prescription sleep aids. If you do experience any of the side effects below11, you can safely lower your melatonin dose and see if that helps, or stop using it altogether. There is no need to wean off of it. 

  • Headache
  • Dizziness
  • Nausea
  • Drowsiness
  • Depression
  • Mild Tremor
  • Mild Anxiety
  • Abdominal Cramps
  • Irritability
  • Reduced Alertness
  • Confusion 
  • Low blood pressure

According to the Mayo Clinic, headaches, dizziness, nausea, and drowsiness are the most common symptoms11. Those who are pregnant or breastfeeding, have an autoimmune disorder, are epileptic, or diagnosed with depression should avoid taking melatonin12. Additionally, anyone with diabetes or high blood pressure should consult their doctor before taking any of these supplements. 

Other Ways To Fall Asleep Fast

Whether or not you want to use supplemental melatonin, the first step to better sleep is to practice good sleep hygiene. Research13 shows that forming good sleep habits is vital to physical, mental, and emotional health. 

As we discussed before, melatonin is naturally produced by the pineal gland and responds to the light or darkness in your environment. The first step, then, to naturally getting your circadian rhythm/melatonin production in order, is light. 

Exposing yourself to morning sunlight by getting out each morning, even for just a quick walk. This will help get your body’s natural circadian rhythm in order, perhaps more than any other tool we can offer. 

You should also minimize artificial light exposure after dark. Remember, melatonin’s production begins with darkness and is impeded by light. If you are in a house filled with bright lights or looking at your phone or watching TV late into the evening, your natural melatonin production will be impacted. 

Blue lights14 in particular (LED lights, smartphones, TVs, computers, tablets, and video games) not only delay melatonin production but also cause more alertness. Therefore, you should stop using your devices several hours before bed. 

You can also increase melatonin production naturally by turning down your thermostat. In fact, for optimal sleep quality, experts recommend sleeping in a colder room between 60 – 67 degrees. 

There are all sorts of other healthy sleeping habits that will help you get to sleep quickly that don’t necessarily involve increasing your melatonin production. For example, be sure your sleep environment is comfortable, cozy, and supportive, including your bed and bedding. You can try listening to relaxing music or investing in a white noise machine if you live in an urban area or under a noisy neighbor. You can also eat particular foods like salmon, almonds, rice, and fruits like kiwis and cherries, and you might even try ditching the pajamas. 

Additional Reading on Melatonin


Melatonin works well for some people more than others. Although it is safe compared to other sleep aids, it does come with possible side effects. If you want to see if melatonin is right for you, start at a low dose. However, if it doesn’t feel right for you, that’s okay. There are many other ways to practice good sleep hygiene and improve your sleep. We also advise consulting your doctor before trying melatonin, especially if you have other health conditions or medications you are taking.


  1. Aulinas MD PhD, Anna. “Physiology of the Pineal Gland and Melatonin”. National Library of Medicine. Last modified December 10, 2019.
  2. Touitou, Y. “Melatonin: hormone and medication”. National Library of Medicine. 1998. 
  3. Boafo, Addo., Greenham, Stephanie., Alenezi, Shuliweeh., Robillard, Rébecca, Pajer, Kathleen., Tavakoli, Paniz., De Koninck, Joseph. “Could long-term administration of melatonin to prepubertal children affect timing of puberty? A clinician’s perspective”. National Library of Medicine. 2019.
  4. Savage, Rosemary A., Zafar, Nowera., Yohannan, Sandesh., Miller, John-Mark M. “Melatonin”. National Library of Medicine. Last modified August 8, 2023. 
  5. Melatonin”. Family Doctor. Last modified. June 22, 2020.
  6. Peuhkuri, Katri., Sihvola, Nora., Korpela, Riitta. “Dietary factors and fluctuating levels of melatonin”. National Library of Medicine. 2012.
  7. Vural, Esmée M S., van Munster, Barbara C., de Rooij, Sophia E. “Optimal dosages for melatonin supplementation therapy in older adults: a systematic review of current literature”. National Library of Medicine. 2014.
  8. Esparham MD, Anna. “Melatonin for Kids: What Parents Should Know About This Sleep Aid”. Healthy Children. Last modified September 26, 2023.
  9. Murcia García, J., Muñoz Hoyos, A., Molina Carballo, A., Fernández García, J M., Narbona López, E., Uberos Fernández, J. “Puberty and melatonin”. National Library of Medicine. 2002.
  10. Tordjman, Sylvie., Chokron, Sylvie., Delorme, Richard., Charrier, Annaëlle., Bellissant, Eric., Jaafari, Nemat., Fougerou, Claire. “Melatonin: Pharmacology, Functions and Therapeutic Benefits”. National Library of Medicine. 2017.
  11. Bauer MD, Brent A. “Is melatonin a helpful sleep aid — and what should I know about melatonin side effects?”. Mayo Clinic. Last modified November 13, 2020.
  12. Melatonin for Sleep: Does It Work?”. Johns Hopkins Medicine. Webpage accessed October 23, 2023.
  13. Gardner, Benjamin., Lally, Phillippa., Wardle, Jane. “Making health habitual: the psychology of ‘habit-formation' and general practice”. National Libary of Medicine. 2012
  14. Blue light has a dark side”. Harvard Health. 2020.

Natalie is a content writer for Sleep Advisor with a deep passion for all things health and a fascination with the mysterious activity that is sleep. Outside of writing about sleep, she is a bestselling author, improviser, and creative writing teacher based out of Austin.

When she's doing none of these things, you will most likely find her outdoors, at the gym, or... asleep.

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