Medically Reviewed by
Dr. Carla Montrond Correia ND, CNS
6 min read
Melatonin is a hormone released by your brain’s pineal gland. It’s naturally released in response to darkness, which is how it got the nickname “hormone of darkness.” There are other parts of your body that are responsible for its production, too, including your bone marrow, retinas, and gastrointestinal tract.
The effect of melatonin in your body is to regulate your body’s circadian rhythm, thereby regulating your sleep cycle. It may also affect your body’s core temperature. It’s available in supplement form to help with sleep problems, as it supports sleep quality, duration, and latency. Most people who use a melatonin supplement do so on a short-term basis to address sleep issues, such as jet lag. In some places, including the United States and Australia, it’s available as an over-the-counter medication, while in Europe, a prescription is required.
While melatonin is best-known for its sleep-aiding qualities, it’s also involved in managing immune function, blood pressure, and cortisol levels. It also acts as an antioxidant and may affect other health conditions. Indeed, some studies have shown that melatonin can help with eye health, brain health, and stomach health.
Your body tends to produce less melatonin as you age. You should check with a medical professional about your melatonin needs.
Melatonin is a hugely popular sleep aid and is a common natural remedy for a variety of sleep issues.
One study involving 50 people with sleep issues demonstrated that taking melatonin two hours before bed helped them fall asleep more quickly and supported better sleep quality. A meta analysis of 19 studies of people with various sleep issues found that melatonin doses cut down on the time it took to fall asleep, increased overall sleep time, and enhanced sleep quality.
Circadian rhythms are the 24-hour cycles that serve as part of your body’s internal clock, always running in the background to help your body with essential functions and processes. Your circadian rhythms are connected to a master clock in the brain. This master clock is specifically found in what’s called the suprachiasmatic nucleus (SCN), located in the hypothalamus, another part of the brain. Perhaps the best-known circadian rhythm is your sleep-wake cycle, which has to do with your body’s relationship to darkness and light. An example of a light-related circadian rhythm would be sleeping when it’s night and being awake when it’s day.
The SCN is sensitive to light. Light or the absence of it provides the SCN with cues for your body’s internal clock. Other cues include exercise, temperature, and social activity – but light remains the most powerful. The SCN therefore controls your production of melatonin. When there’s less light, the SCN has the brain make more melatonin to prepare you to go to bed. Of note, the light from your electronic devices at night can complicate your circadian rhythm by altering your brain’s production of melatonin.
Melatonin is available in doses of 0.5-10 mg per day. While there’s no standard for an initial dose, it’s typically best to start with a lower dose – perhaps between 1 to 3mg – and go up as needed. Consult with a medical professional about what would work best for your particular sleep problems.
Melatonin levels in your body change as you age. One meta-analysis of 16 studies found that taking higher doses of melatonin resulted in higher serum and urine samples in older adults over a long period of time, as compared with younger adults. As a result, these older adults experienced more daytime drowsiness. The more melatonin the older adult took, the drowsier they became. Consequently, researchers suggest that older adults use lower doses of melatonin, as these doses will help older adults sleep better without causing major disruptions to their circadian rhythms. This suggests that melatonin supplements may take longer to metabolize in older adults and it may be beneficial to start off with smaller doses. Indeed, older adults can benefit from a dosage of less than 1mg. Talk to a medical professional before deciding what’s right for you.
There is no clear recommended dosage of melatonin based on weight, though your weight may be relevant. Consult with a medical professional about the right dosage for you.
If your main concern is for getting to sleep, you can take melatonin about a half-hour before bedtime. If, rather, you’re trying to correct your circadian rhythm and find a more regular sleep schedule, consider taking it 2-3 hours before bed.
In general, you should avoid supplementing your children with melatonin unless recommended by a doctor. Studies show that of half the cases where melatonin was used to treat sleep issues in children, simply encouraging better sleep habits was just as effective. There haven’t been enough studies to determine a recommended dosage for children or to determine the potential long-term effect of melatonin-based treatment for children.
Alcohol has a sedating effect and it affects your circadian rhythm. Because alcohol disrupts your natural melatonin levels, it is not safe to take melatonin with alcohol.
While melatonin has shown few side effects after short-term use, more research is needed to determine potential longer-term impact.
Due to the limited research regarding pregnancy and melatonin, it could be best for pregnant people to avoid use.
Taking too much melatonin can result in sleepiness, agitation, nausea, and possibly irritation. Too much melatonin can have the opposite of the desired effect, making it harder to sleep and throwing your circadian rhythm into flux. Read below for more information about melatonin’s possible side effects.
Just as there is only limited research regarding pregnancy and melatonin, there is little known about the effect of melatonin on people who are breastfeeding. It’s best to avoid melatonin use if you’re:
Furthermore, you should consult a medical professional about melatonin if you are or have been afflicted by any of the following:
While melatonin is generally safe, you should be aware of some potential side effects. Some side effects can include:
Less common side effects include:
There are some basic steps you can take to improve your sleep habits: keeping a regular bedtime schedule, avoiding screens before bed, eating a healthy diet, exercising, working in some relaxation strategies (meditation and yoga, possibly). But if sleep issues persist, you might want to consider a melatonin supplement as a short term strategy. It’s a tested method of improving sleep and it’s been successfully tried by many people.