Poor sleep affects roughly 50–70 million Americans. In fact, according to some studies, up to 30% of adults in the United States report that they sleep for less than 6 hours each night.
Although it’s a common problem, poor sleep may have severe consequences.
Poor sleep can deplete your energy, lower your productivity, and increase the risk of diseases such as high blood pressure and diabetes.
Melatonin is a hormone that tells your body when it’s time to head to bed. It’s also become a popular supplement among people having trouble falling asleep.
This article explains how melatonin works as well as its safety and how much to take.
- What it is
- How it works
- Effect on sleep
- Other benefits
- Safety and side effects
- In pregnancy
- For babies
- For kids
- For older adults
What is melatonin?
Melatonin is a hormone that your body makes naturally.
It’s produced by the pineal gland in the brain, but it’s also found in other areas, such as the eyes, bone marrow, and gut.
It’s often called the “sleep hormone,” as high levels can help you fall asleep.
However, melatonin itself will not knock you out. It simply lets your body know that it’s nighttime so you can relax and fall asleep easier.
Melatonin supplements are popular among people with insomnia and jet lag. You can get melatonin in many countries without a prescription.
It may help:
- support eye health
- treat stomach ulcers and heartburn
- ease tinnitus symptoms
- raise growth hormone levels in men
Summary: Melatonin is a hormone that the pineal gland makes naturally. It helps you fall asleep by calming the body before bed.
How does melatonin work?
Melatonin works together with your body’s circadian rhythm.
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In simple terms, the circadian rhythm is your body’s internal clock. It lets you know when it’s time to:
Melatonin also helps regulate your body temperature, your blood pressure, and the levels of some hormones.
Melatonin levels start to rise in your body when it’s dark outside, signaling to your body that it’s time to sleep.
It also binds to receptors in the body and can help you relax.
For instance, melatonin binds to receptors in the brain to help reduce nerve activity.
It can reduce levels of dopamine, a hormone that helps you stay awake. It’s also involved in some aspects of the day-night cycle of your eyes.
Although the exact way melatonin helps you fall asleep is unclear, research suggests these processes can help you fall asleep.
Conversely, light modulates melatonin production, which is one way that your body knows it’s time to wake up.
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As melatonin helps your body prepare for sleep, people who do not make enough of it at night can have trouble falling asleep.
Many factors may cause low melatonin levels at night.
Stress, smoking, exposure to too much light at night (including blue light), not getting enough natural light during the day, shift work, and aging all affect melatonin production.
Taking a melatonin supplement may help counter low levels and normalize your internal clock.
Summary: Melatonin works closely with your body’s circadian rhythm to help prepare you for sleep. Its levels rise at nighttime.
Melatonin may help you fall asleep
While additional research is needed, current evidence indicates that taking melatonin before bed may help you get to sleep.
For example, an analysis of 19 studies on people with sleep disorders found that melatonin helped reduce the time it took to fall asleep by an average of 7 minutes.
In many of these studies, people also reported significantly better quality of sleep.
Additionally, melatonin can help with jet lag, a temporary sleep disorder.
Jet lag occurs when your body’s internal clock is out of sync with the new time zone. Shift workers may also experience jet-lag symptoms since they work during a time normally saved for sleep.
Melatonin can help reduce jet lag by syncing your internal clock with the time change.
For instance, an analysis of nine studies explored the effects of melatonin in people who traveled through five or more time zones. Scientists found that melatonin was remarkably effective at reducing the effects of jet lag.
The analysis also found that both lower doses (0.5 milligrams) and higher doses (5 mg) were equally effective at reducing jet lag.
Summary: Evidence shows that melatonin may help you fall asleep faster. In addition, it may help people with jet lag get to sleep.
Other health benefits of melatonin
Taking melatonin may provide you with other health benefits as well.
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Melatonin may support eye health
Healthy indole-derived melatonin levels may support eye health.
It has powerful antioxidant benefits that could help lower the risk of eye diseases, such as age-related macular degeneration (AMD).
In one study, scientists asked 100 people with AMD to take 3 mg daily of melatonin over 6 to 24 months. Taking melatonin daily seems to protect the retinas and delay damage from AMD, without any significant side effects.
Melatonin may help treat stomach ulcers and heartburn
The antioxidant properties of melatonin may help treat stomach ulcers and alleviate heartburn.
A study with 21 participants found that taking melatonin and tryptophan along with omeprazole helped stomach ulcers caused by the bacteria H. pylori heal faster.
Omeprazole is a common medication for acid reflux and gastroesophageal reflux disease (GERD).
In another study, 36 people with GERD were given either melatonin, omeprazole, or a combination of both to treat GERD and its symptoms.
Melatonin helped reduce heartburn and was even more effective when combined with omeprazole.
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Future studies will help clarify how effective melatonin is in treating stomach ulcers and heartburn.
Melatonin may reduce symptoms of tinnitus
Tinnitus is a condition characterized by a constant ringing in the ears. It’s often worse when there’s less background noise, such as when you’re trying to fall asleep.
Interestingly, researchers recommend considering taking melatonin to help reduce symptoms of significant tinnitus and help you get to sleep.
In one study, 61 adults with tinnitus took 3 mg of melatonin before bed for 30 days. It helped reduce the effects of tinnitus and significantly improved sleep quality.
Melatonin may help increase growth hormone levels in men
Human growth hormone (HGH) is naturally released during sleep. In healthy young men, taking melatonin may help increase HGH levels.
Studies have shown that melatonin can make the pituitary gland, the organ that releases HGH, more sensitive to the hormone that releases HGH.
In addition, one small study showed that both lower (0.5 mg) and higher (5 mg) melatonin doses are effective at stimulating HGH release.
Another study found that 5 mg of melatonin combined with resistance training increased the levels of HGH in men while lowering the levels of somatostatin, a hormone that inhibits HGH.
Summary: Melatonin may support eye health, ease tinnitus symptoms, treat stomach ulcers and heartburn, and increase growth hormone levels in young men. Speak with a healthcare professional first if you’re considering melatonin supplementation to help treat any of the conditions mentioned to learn if it’s right for you and whether there are any medication interactions.
How to take melatonin
If you’re considering trying melatonin, starting with a lower-dose supplement is recommended. However, it’s important to talk with a healthcare professional before adding over-the-counter melatonin to your treatment regimen.
For instance, start with 0.5 mg (500 micrograms) or 1 mg 30 minutes before going to bed. If that does not seem to help you fall asleep, try increasing your dose to 3–5 mg.
Taking more melatonin than this likely will not help you fall asleep faster. The goal is to find the lowest dose that’ll help you fall asleep.
However, it’s best to follow the instructions that come with your supplement.
Melatonin is widely available in the United States. You’ll need a prescription for melatonin in other places, such as the European Union and Australia.
Summary: If you want to try melatonin, start with 0.5 mg (500 micrograms) or 1 mg 30 minutes before bed. If that does not work, try increasing it to 3–5 mg or follow the instructions on the supplement. If you’re considering melatonin supplementation, talk with a healthcare professional first to find out if it’s right for you and whether there are any medication interactions.
Safety and side effects of melatonin
Current evidence suggests that melatonin supplements are safe, non-toxic, and not addictive.
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That being said, some people may experience mild side effects, such as:
Melatonin may also interact with a variety of medications. These include:
- sleep aids or sedatives
- blood thinners
- blood pressure medication
- oral contraceptives
- diabetes medications
If you have a health condition or take any of the above medications, it’s best to talk with your doctor before beginning a supplement.
There’s also some concern that taking too much melatonin will stop your body from making it naturally.
However, several studies have found that taking melatonin will not affect your body’s ability to make it on its own.
Summary: Current studies show that melatonin is safe, nontoxic, and not addictive. However, it may interact with medications, such as blood thinners, blood pressure medications, and antidepressants.
Melatonin and alcohol
Dips in melatonin can occur following evening alcohol consumption. One study in 29 young adults found that alcohol consumption 1 hour before bed could reduce melatonin levels by up to 19%.
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Low levels of melatonin have also been detected in individuals with alcohol use disorder (AUD).
Further, melatonin levels rise more slowly in individuals with an alcohol dependency, meaning it can be harder to get to sleep.
However, melatonin supplementation does not improve sleep in these cases. A study of people with AUD found that, compared with a placebo, receiving 5 mg of melatonin a day for 4 weeks did not improve sleep.
It’s been proposed that the antioxidant effects of melatonin may help prevent or treat alcohol-related illnesses. However, additional research is needed to test this claim.
Summary: Drinking before bed can decrease your levels of melatonin and may affect sleep. While low levels of melatonin are seen in those with alcohol use disorder (AUD), melatonin supplementation does not improve their sleep.
Melatonin and pregnancy
Your natural melatonin levels are important during pregnancy. Melatonin levels fluctuate throughout pregnancy.
During the first and second trimesters, the nighttime peak of melatonin decreases.
However, as the due date approaches, melatonin levels begin to rise. At term, melatonin levels reach a maximum. They’ll return to pre-pregnancy levels after delivery.
Maternal melatonin is transferred to the developing fetus where it contributes to the development of circadian rhythms as well as both the nervous and endocrine systems.
Melatonin also appears to have a protective effect on the fetal nervous system. It’s believed that the antioxidant qualities of melatonin protect the developing nervous system from damage due to oxidative stress.
While it’s clear that melatonin is important throughout pregnancy, there are limited studies on melatonin supplementation during pregnancy.
Because of this, it’s currently not recommended that pregnant women use melatonin supplements.
Summary: Melatonin levels change throughout pregnancy and are important for the developing fetus. However, melatonin supplementation is not currently recommended for pregnant people.
Melatonin and babies
During pregnancy, maternal melatonin is transferred to the developing fetus. However, following birth, a baby’s pineal gland begins making its own melatonin.
In babies, melatonin levels are lower during the first 3 months after birth. After this period, they increase, likely due to the presence of melatonin in breast milk.
Maternal melatonin levels are highest at night. Because of this, it’s believed that breastfeeding in the evening may help to contribute to the development of a baby’s circadian rhythms.
While melatonin is a natural component of breast milk, no data exist on the safety of melatonin supplementation while breastfeeding. Because of this, it’s often recommended that breastfeeding mothers avoid using melatonin supplements.
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Summary: Although babies begin producing their own melatonin after birth, levels are initially low and are naturally supplemented by maternal breast milk. Melatonin supplements are not recommended for nursing mothers.
Melatonin and children
It’s estimated that up to 25% of healthy children and adolescents have trouble falling asleep.
This number is higher — up to 75% — in children with neurodevelopmental disorders, such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).
The effectiveness of melatonin in children and adolescents is still being investigated.
One literature review looked at seven trials of melatonin use in this population.
Overall, it found that children receiving melatonin as a short-term treatment had a better sleep onset than the children receiving a placebo. This means that it took them less time to fall asleep.
A small study followed up on people who had been using melatonin since childhood, for about 10 years. It found that their sleep quality was not notably different from that of the control group who had not used melatonin.
This suggests that sleep quality in people who had used melatonin as children normalized over time.
Studies of melatonin for children with neurodevelopmental disorders, such as ASD and ADHD, are ongoing, and the results have been varied.
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Generally, they’ve found that melatonin may help children diagnosed with a neurodevelopmental disorder sleep longer, fall asleep faster, and have better sleep quality.
Melatonin is well tolerated in children. However, there’s some concern that long-term use may delay puberty, as a natural decline of evening melatonin levels is associated with the onset of puberty. More studies are needed to investigate this.
Melatonin supplements for children are often found in the form of gummies.
Dosage can vary by age with some recommendations, including 1 mg for infants, 2.5 to 3 mg for older children, and 5 mg for young adults.
Overall, more research is needed to determine the optimal dosage and efficacy of melatonin use in children and adolescents.
Additionally, because researchers do not yet understand the long-term effects of melatonin use in this population, it may be best to try to implement good sleep practices before trying melatonin.
Summary: Melatonin may help to improve sleep onset in children as well as various aspects of sleep quality in children with neurodevelopmental disorders. However, the long-term effects of melatonin treatment in children are still unknown.
Melatonin and older adults
Melatonin secretion decreases as you age. These natural declines may potentially lead to poor sleep in older adults.
As with other age groups, the use of melatonin supplementation in older adults is still being investigated. Studies indicate that melatonin supplementation may improve sleep onset and duration in older adults.
One literature review found that there’s some evidence for using low-dose melatonin for older people who are having trouble sleeping. However, more research is needed.
Melatonin may also help in people with mild cognitive impairment (MCI) or Alzheimer’s disease.
Some studies have shown that melatonin can potentially improve sleep quality, and the feeling of feeling rested, and morning alertness in individuals diagnosed with these conditions. Research into this topic is ongoing.
While melatonin is well tolerated in older adults, there are concerns about increased daytime drowsiness. Additionally, the effects of melatonin may be prolonged in older individuals.
The most effective dose of melatonin for older adults has not been determined.
A recent recommendation suggests that a maximum of 1 to 2 mg be taken 1 hour before bedtime. It’s also recommended that immediate-release tablets be used to prevent prolonged levels of melatonin in the body.
Summary: Melatonin levels naturally decrease as you get older. Low-dose supplementation with immediate-release melatonin may help to improve sleep quality in older adults. Older adults must talk with their doctor first if they’re considering melatonin supplementation to discuss whether it’s right for them and any possible drug interactions.
Melatonin is an effective supplement that may help you fall asleep, especially if you have insomnia or jet lag. It may have other health benefits as well.
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If you’re considering melatonin, starting with a lower dose of 0.5–1 mg, taken 30 minutes before bed is recommended. If that does not work, you can increase your dose to 3–5 mg.
It’s important to talk with a healthcare professional first to learn if melatonin supplementation is right for you and whether there are any medication interactions. Also, melatonin may make some conditions worse.
Melatonin is generally well tolerated, although there’s a potential for mild side effects. Some medications may interact with melatonin.
Talk with your doctor if you’re taking these medications.Last updated on January 4, 2022, and last reviewed by an expert on December 20, 2021.