Skip to Content

Melatonin: Worth Losing Sleep Over?

Medically reviewed by L. Anderson, PharmD. Last updated on May 15, 2018.

What Is Melatonin?

Melatonin - you've probably seen it in the vitamin section of your pharmacy. But melatonin is not a vitamin. Basically, melatonin is the hormone your body naturally secretes that tells you when it's time for bed.

Natural melatonin is formed from the amino acid tryptophan in our bodies and then released to our melatonin receptors in the brain. It helps to control our sleep and wake cycles. In fact, nighttime melatonin hormone levels are roughly 10 times higher than in the daytime.

Melatonin release is increased each day in response to darkness, peaking at about 2 to 3 AM.

Melatonin Uses

Synthetic melatonin tablets have been used:

  • to help minimize jet lag
  • to help adjust sleep cycles in the blind
  • for shift-work sleep disorders in people with alternating work schedules
  • for other sleep disorders.

Studies are also looking at its use in seasonal affective disorder (SAD). But how effective is melatonin and what about its safety?

The regulation of melatonin products varies by country. In the U.S., melatonin is can be purchased without a prescription in the pharmacy or health food store. Strengths range from 1 milligram (mg) to 10 mg, and come as tablets, capsules, oral liquid, lozenges, timed-release forms, and even chewable gummies. On average a 120-count bottle costs about $10.00.

How Safe Is Melatonin?

In general, melatonin is a relatively safe supplement; and side effects are uncommon. In fact, most side effects occur at a lower or equal rate to placebo (a fake sugar pill).

However, some people can have side effects from melatonin that can include:

  • Feeling sleepy, weak, confused in the daytime
  • Vivid dreams
  • Depressed mood
  • Headache
  • Loss of appetite, diarrhea, nausea
  • Minor blood pressure changes
  • Back pain, joint pain

Jet Lag Is A Drag

Jet lag may be one of the most common uses for melatonin.

Jet lag is a travel problem that causes:

  • difficulty in falling asleep or staying asleep
  • fatigue
  • trouble concentrating
  • constipation.

Jet lag is much more likely if you cross over several time zones, getting worse with the number of time zones you cross.

Given enough time (3 to 5 days), jet lag will usually resolve on its own, but this is not always optimal, especially for busy professionals or eager tourists on the go.

What is the Dose of Melatonin For Jet Lag?

For jet lag minimization, there is a specific way you should take melatonin. Effective starting doses for insomnia or jet lag should start on the lower end of melatonin dosing (0.3 to 0.5 mg), and range upwards to 5 mg. Different doses may be effective for different people. Doses of 3 to 5 mg at bedtime are commonly used.

If you are traveling east, say from the US to Europe, take the melatonin after dark, 30 minutes before bedtime in the new time zone or if you are on the plane. Then for the next 4 nights in the new time zone, take it again after dark, 30 minutes before bedtime. Appropriately timed light exposure therapy can also be helpful when combined with melatonin for eastward travel.

Westbound travel does not always require melatonin use, and it may not be helpful. If you are heading west, for example, from the US to Australia, a dose is not needed for your first travel night, but then take it for the next 4 nights in the new time zone, after dark, 30 minutes before bedtime, if needed. Either way, do not drive if you are drowsy when you arrive at the airport.

Are There Drug Interactions With Melatonin?

Yes, there can be some important drug interactions with melatonin; melatonin is structurally similar to serotonin.

Melatonin may have a more significant drug interaction with these medications, possibly increasing the blood levels of melatonin or causing other side effects:

Check with your doctor before you take melatonin with ANY medication. Do not stop using any medications without first talking to your doctor.

Melatonin and Blood Thinners

If you take melatonin with warfarin, you may need to have your blood clotting monitored more closely.

As with many supplements, the risk for bruising or bleeding may be increased when melatonin is combined with anticoagulants (blood thinners) or drugs that elevate the risk for bleeding, such as:

These medications might not be safe when combined with melatonin.

Tell your doctor or pharmacist about all medicines and supplements you take, including over-the-counter (OTC) medicines and herbal supplements.

Liver Enzymes and Melatonin: Explained

Melatonin is primarily broken down (metabolized) in the liver by enzymes known as cytochrome P450 enzymes prior to being excreted from the body. Other drugs are also metabolized by these enzymes.

Theoretically, when melatonin is combined with these other drugs also broken down by the same enzymes there can be competition. Why is this a problem? There's only so much enzyme to go around, and blood levels of melatonin or the other drugs may rise, leading to increased side effects and drug toxicity.

Some drugs that might cause problems include:

  • Amitriptyline (Elavil)
  • Carisoprodol (Soma)
  • Citalopram (Celexa)
  • Diazepam (Valium)
  • Lansoprazole (Prevacid)
  • Omeprazole (Prilosec)
  • Phenytoin (Dilantin)
  • Warfarin (Coumadin, Jantoven)
and many others.

This is another good reason to have a drug interaction screen and use melatonin cautiously.

Melatonin Use in Children

Although melatonin products exist over-the-counter (OTC) for use in children, it is best to only use melatonin for your child under the direction of a pediatrician or other medical specialist. Causes of insomnia should always be evaluated in children to determine if there is some underlying medical or behavioral cause. Melatonin should not be used to "force sleep" in otherwise healthy children.

According to a consensus guideline, children with developmental disorders, such as autism spectrum disorder, attention-deficit/hyperactivity disorder, and intellectual disability can have sleep disturbances and may benefit from melatonin treatment. These authors note that melatonin:

  • decreases sleep onset latency
  • increases total sleep time
  • does not decrease nighttime awakenings.

Side effects are infrequent with melatonin, but use in children over the longer term is not well studied. Reported side effects with melatonin use in children are:

  • morning sleepiness
  • “fogginess"
  • increased enuresis (bed-wetting).

Data does not support that theory of an increased risk for seizures in children. There is no evidence to support the effectiveness of extended-release melatonin over immediate-release.

Can Melatonin Cause Seizures?

Melatonin may rarely lower the seizure threshold, leading to a greater risk of seizures.

In children with severe neurological disorders who use melatonin for sleep, this may be especially true. Plus, if you are taking a drug that increases your risk for seizures, or have epilepsy, taking melatonin alongside may boost this risk.

Examples of drugs that might increase the seizure risk include:

  • some antibiotics
  • general anesthetics
  • narcotics
  • ADHD stimulants like methylphenidate (Ritalin)

Be sure to tell your healthcare provider that you use melatonin and always have your pharmacist run a drug interaction check, even with over-the-counter (OTC) medicines.

Electronics and Bedtime

Electronic devices, like iPhones, iPads, and TVs often find their way into the bedroom at night, emitting blue light from their screens. This can be especially problematic for kids.

Researchers have found that the bright light of these devices may lower levels of natural melatonin. The effect was most significant for children just entering puberty, with nighttime melatonin levels suppressed by up to 37% in certain cases.

While the study does not prove that bright light worsens sleep, it does show that it alters melatonin levels which may be the culprit to a bad night's sleep.

A Hard Day's Night

A hard time getting to sleep at night and staying asleep is a common complaint for many adults, and it can get worse after age 55 as melatonin levels drop drastically as we age. In fact, in February 2016, the CDC reported that over a third of US adults don't get a good night's sleep.

Insomnia can be due to any number of causes such as:

  • Excessive caffeine, smoking, alcohol use, or late night meals
  • Travel, late-night exercising, mid-day napping
  • Pain, acute or chronic
  • Medication side effects
  • Depression, anxiety
  • Need to urinate
  • Sleep apnea
  • Temperature or humidity
  • Blue light from electronics at night

The Night Owl

Eliminating the fixable causes for your insomnia is the first goal, and referral to a sleep specialist is recommended if there is no success.

Studies have found melatonin doses ranging from 0.5 to 10 mg given 30 to 60 minutes before bedtime to be effective. It's best to start with a lower dose and increase if needed.

Timed-release melatonin may be effective, as well, given 1 to 2 hours before bedtime. However, don't drink alcohol with the time-release preparation; it can disrupt the time-release mechanism. And don't forget, excessive alcohol use at night can lead to early awakening and be disruptful to sleep in general, too.

A trial of melatonin may be worthwhile for insomnia or jet lag, but check with your doctor and start with low doses from 0.3 to 0.5 mg.

To stay up-to-date and ask questions related to melatonin and sleep-disorders, join the Melatonin Support Group.

Recap: Clinical Use of Melatonin

In the US, melatonin is commonly used for:

  • jet lag
  • sleep disorders and other insomnias.
  • sleep disorders in the blind
  • workers with odd shifts that are disruptful to sleep
  • short-term relief of general insomnia.

Melatonin may be preferable to other sedatives due to lower risk of side effects and addiction.

In the US, melatonin is easily accessible at the pharmacy for a relatively low cost. Dosing should start low (0.3 to 0.5 mg about 30 minutes to one hour before bed) and increase only if needed. One milligram (mg) tablets can be cut in half to get a 0.5 mg dose, if needed (but do not cut the timed-release product).

Side effects are minimal, but drug interactions may go undetected unless a drug interaction review is performed with all over-the-counter, herbal and prescribed drugs.

Studies looking at long-term use of melatonin, especially in children, are not widely available, raising concerns about use in this population. Always seek a pediatrician's advice before giving melatonin to any child.

Finished: Melatonin: Worth Losing Sleep Over?

Need To Catch Some Shut-Eye? Tips on Getting the Sleep You Need

Trouble falling or staying asleep is one of the most common medical complaints. Sometimes, just a few simple changes in lifestyle can make a big impact so you can get…


  • Bruni O, Alonso-Alconada D, Besag F, et al. Current role of melatonin in pediatric neurology: clinical recommendations. Eur J Paediatr Neurol. 2015 Mar;19(2):122-33. Acessed May 15, 2018 at
  • Owen, J, et al. Pharmacotherapy for insomnia in children and adolescents: A rational approach. Up to Date. Accessed May 15, 2018 at
  • Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews 2002, Issue 2. Art. No.: CD001520. DOI: 10.1002/14651858.CD001520. Accessed May 11, 2018 at
  • Kemp C. American Academy of Pediatrics (AAP) News. Melatonin does little to improve sleep in children with developmental disorders. Feb. 2013. Vol. 34 (2); Accessed May 11, 2018 at
  • Blackmer A. Feinstein J. Management of Sleep Disorders in Children With Neurodevelopmental Disorders: A Review. Pharmacotherapy 2016;36(1):84–98) doi: 10.1002/phar.1686. Accessed May 11, 2018 at
  • Natural Medicines Comprehensive Database. Melatonin. Updated 12/2015. Accessed May 11, 2018 at
  • van Geijlswijk IM, Korzilius HP, Smits MG. The use of exogenous melatonin in delayed sleep phase disorder: a meta-analysis. Sleep. 2010 Dec;33(12):1605-14. Accessed May 11, 2018 at
  • Circadin (melatonin). Medsafe (New Zealand). Accessed May 11, 2018 at
  • BPAC Guidelines NZ. Issue 72; December 2015. Melatonin: is it worth losing any sleep over? Accessed May 11, 2018 at
  • Light From Smartphones, Tablets May Lower Sleep Hormone in Kids. Sept. 2, 2015, 2015. Accessed May 6, 2017 at

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.