Melatonin, often referred to as
the sleep hormone, is a central part of the body’s sleep-wake cycle. Its
production increases with evening darkness, promoting healthy sleep and helping
to orient our circadian rhythm.
body naturally produces melatonin, but researchers and the
public have increasingly taken an interest in external sources of it, such as
liquids or capsules, as a way to address sleep difficulties. In the United
States, melatonin is sold as a dietary supplement, and a 2012 survey by the
National Institutes of Health found it to be one of the most commonly used
supplements among both adults1 and children2.
Studies have found that
melatonin can improve sleep in certain cases, but it isn’t for everyone. It is
important to be aware of and carefully consider melatonin’s potential benefits
and downsides. People who want to use melatonin supplement should also be aware
of issues related to dosage and the quality of supplements The.
Melatonin is a natural
hormone3 that
is produced by the pineal gland in the brain and then released into the
bloodstream. Darkness prompts the pineal gland to start producing melatonin
while light causes that production to stop. As a result, melatonin helps
regulate circadian rhythm and synchronize our sleep-wake cycle
with night and day. In doing so, it facilitates
a transition to sleep4 and
promotes consistent, quality rest.
Melatonin created within the body is known as endogenous
melatonin, but the hormone can also be produced externally. Exogenous melatonin
is normally made synthetically5 in a laboratory and, as a dietary
supplement, is most often sold as a pill, capsule, chewable, or liquid.
Can
Melatonin Supplements Improve Sleep?
It is well-established that
melatonin produced by the body plays a fundamental role in getting quality
sleep, so it’s natural to consider whether melatonin supplements can be used to
address sleeping difficulties.
Research to date has shown that
melatonin supplements may be useful in certain situations for both adults and
children.
Melatonin in
Adults
In adults, research studies
have found the clearest potential benefits from melatonin are for people who
have sleeping problems related to Delayed Sleep-Wake Phase Disorder (DSWPD) and
jet lag.
DSWPD is a circadian rhythm disorder in which a person’s sleep
schedule is shifted later, often by a matter of hours. For people with this
“night owl” schedule, it can be hard to get enough sleep if they have
obligations, such as work or school, that force them to wake up early in the
morning. Studies have indicated that low doses of melatonin taken before the
desired bedtime can help
people with DSWPD adjust their sleep cycle6 forward.
Jet lag can occur when a person travels rapidly across multiple
time zones, such as on an intercontinental flight, because their body’s
internal clock becomes misaligned with the local day-night cycle. Evidence from
small research studies points to melatonin supplements as potentially helping to reset the sleep-wake cycle 7and improve sleep in people with jet lag.
Shift workers — people who work during the night —
often struggle with sleep difficulties related to a misaligned circadian
rhythm. Studies of melatonin in shift workers have had inconclusive results,
although some people report a benefit.
There is debate about whether melatonin is beneficial in
otherwise healthy adults who have insomnia, a persistent condition marked by
trouble falling asleep or staying asleep. The existing research is not
conclusive. Some experts reviewing it find
some evidence in favor of melatonin8 while
organizations like the American Academy of Sleep Medicine (AASM) have concluded
that there is not sufficient scientific
support9 for
melatonin in reducing insomnia.
For most adults, melatonin has
few notable side effects, so even when its benefits may not be clearly
established, some people with sleeping problems may be inclined to try it. The best
practice is to consult a doctor and have an in-depth conversation about the
benefits and risks before taking melatonin.
Melatonin
may be helpful in children with sleeping problems, but experts generally agree
that more research is needed to understand its optimal use in young people.
Several research studies have indicated that melatonin may help
children with sleeping difficulties fall
asleep more quickly10. It
may also improve their total sleep time11. The American Academy of Pediatrics (AAP)
states that melatonin may be beneficial as a short-term tool12 to
help children adjust to a healthier sleep schedule and establish good sleep
habits.
Evidence from small studies has indicated that melatonin may be
especially useful in children with certain conditions including epilepsy13 and
some neuro developmental disorders such as Autism Spectrum Disorder14 (ASD).
Almost all reviews of the
existing science acknowledge that additional research will be needed to clarify
key issues about the use of melatonin in children including the optimal dosage
and duration of use as well the risks of long-term side effects.
Because of the uncertainties
the remain regarding melatonin’s use by children, the AAP recommends that
parents work closely with their child’s doctor before administering melatonin
supplements.
Additional
Steps to Improve Sleep
People with sleeping problems can benefit from taking steps to
develop healthy sleep habits. Even if melatonin offers
relief, improving their sleep routines and environment (mattress and bedding) —
known collectively as sleep hygiene — can promote durable sleep quality
improvement.
Talking with a doctor about melatonin and sleeping problems can
also help reveal whether a person has an underlying sleep disorder. For
example, raising poor sleep issues or excessive sleepiness may uncover a
problem like sleep apnea. Melatonin isn’t a therapy for sleep
apnea, but in this scenario, working with the doctor can lead to more
appropriate and effective treatments.
What Are the
Side Effects of Melatonin?
Short-term use of melatonin has relatively few side effects5 and
is well-tolerated by the majority of people who take it. The most commonly reported side effects 15 are daytime drowsiness, headaches,
and dizziness, but these are experienced by only a small percentage of people
who take melatonin.
In children, the reported side
effects of short-term use are similar as in adults. Some children may
experience agitation or an increased risk of bedwetting when using melatonin.
For both children and adults,
talking with a doctor before taking melatonin can help prevent possible
allergic reactions or harmful interactions with other medications. People
taking anti-epilepsy and blood thinning medications, in particular, should ask
their physician about potential drug interactions.
The American Academy of Sleep Medicine recommends against
melatonin use in people with dementia, and
there is little research about its safety in women who are pregnant or
breastfeeding.
There is also very little data about the long-term effects of
melatonin supplements in children or adults. There is some concern that
sustained use of melatonin could affect the onset of puberty in children,
but research so far is inconclusive16. Because the long-term effects are
unknown, people should maintain an ongoing conversation with their doctor about
using melatonin and the quality of their sleep and overall health.
What is the
Appropriate Dosage of Melatonin?
There is no consensus about the
optimal dosage of melatonin although most experts advise to avoid extremely
high dosages. In studies, dosages range from .1 to 12 milligrams (mg). A
typical dose in supplements is between one and three milligrams, but whether
this is appropriate for any specific person depends on factors like their age
and sleeping problems. You may find melatonin in dosages of micrograms (mcg),
1000 mcg melatonin
10 mg.
Some people experience daytime
sleepiness when using melatonin as a sleep aid. If you experience this, it
could be that your dosage is too high. It’s advisable to start with the lowest
dosage possible and work your way up gradually under the supervision of your
doctor.
The AAP advises against dosages
above 3-6 mg for children and states that many young people respond to small
doses of .5 to 1 mg. Some studies have found benefits to lower doses in adults
as well.
Oral supplements can bring the levels of melatonin in the blood
to levels much higher than is normally produced by the body. For example,
dosages between 1-10 mg can raise melatonin concentrations to anywhere from 3 to 60 times typical levels7. For this reason, people taking melatonin
should use caution before ingesting high doses.
How to
Choose Melatonin Supplements
A wide range of brands with varying formulations and dosages are
available over-the-counter in groceries and drugs stores, but there are
important quality differences to look out for. A study that reviewed 31
melatonin supplements found
major inaccuracies in dosage information17; 71%
of the tested products were not within 10% of their listed dosage. An incorrect
dose of melatonin can have meaningful
consequences18 including
a higher risk of side effects and reduced supplement effectiveness.
Some products labeled as only containing melatonin contained
impurities or other compounds, such as serotonin, that can pose health risks.
Melatonin is often combined with magnesium, valerian root, or other natural
sleep aids in supplements, which may further affect the accuracy of
dosages and labeling.
Buyers of supplements should take care when shopping19 and
remember that labels like “natural,” “certified,” and “verified” are not
standardized or regulated. Although not a guarantee of safety, certification
from organizations like US Pharmacopeia (USP), ConsumerLab.com, or the NSF
International Dietary Supplement program can offer confirmation that products
have been tested for contaminants or mislabeling.
