Melatonin turns out to be a natural hormone. At dusk, when darkness sets in, melatonin is secreted by the brain to promote sleep.
Synthetic or lab-made versions of melatonin are widely available as a sleep aid supplement. For people who have difficulty falling asleep, taking melatonin before bedtime can be helpful. Melatonin can also reduce jet lag and help treat circadian rhythm disturbances.
Potential side effects:
Side effects from melatonin tend to be relatively rare and mild. Better research is still needed, but the available data suggests that melatonin is generally safe for short-term use, up to three months.
Adverse effects tend to occur with higher doses or with supplements designed to provide sustained release of melatonin. Along with headaches, dizziness, nausea, and daytime sleepiness, some studies have reported side effects such as vivid dreams, nightmares, stomach cramps, irritable mood, and brief bouts of depression.
Melatonin may remain active in the body for longer periods in older people. This means that melatonin may be more likely to cause next-day drowsiness when taken by older people.
Side effects in children:
Melatonin is generally considered safe for time-limited use in children, but more studies are needed to determine its long-term effects in young people. Based on the limited research to date, the potential short-term side effects of melatonin in children appear to be mild. They may include:
- Increased nighttime urination or bedwetting.
Some researchers worry that melatonin disrupts normal hormone levels and interferes with puberty. But studies that have followed melatonin use for up to four years have found no significant risk for children.
It’s important to keep in mind that while melatonin can help treat some sleep disorders, medical professionals don’t recommend it as a general sleep aid for children and teens.
There is evidence that melatonin can be helpful for children with insomnia or circadian rhythm delay. But parents and caregivers should avoid using melatonin to induce sleep in healthy children or adolescents. Experts suggest starting with lifestyle and behavioral changes before trying melatonin or medications.
Consulting a pediatrician can provide the most direct advice on the benefits and risks of using melatonin for a specific child.
Melatonin and pregnancy:
People who are pregnant or breastfeeding may avoid taking melatonin because there is no evidence that it is safe in these situations.
Anyone who is pregnant or breastfeeding and has difficulty sleeping should talk to their doctor before taking melatonin.
Side effects of melatonin are also generally unknown for people trying to get pregnant. With insufficient evidence for melatonin’s impact on conception, some experts recommend avoiding melatonin supplements as a precaution when trying to become pregnant.
Is melatonin safe?
Melatonin is not for everyone, and some people should be careful and consult a doctor before taking melatonin supplements.
People on dialysis or with liver problems: People with reduced kidney or liver function may not be able to metabolize melatonin and have a higher risk of adverse side effects.
Older people with dementia: The American Academy of Sleep Medicine recommends that older people with dementia avoid taking melatonin. For these people, the potential safety risks of melatonin probably outweigh the possible benefits.
People with depression: Melatonin can cause symptoms of depression or make existing symptoms worse in some people.
People with immune problems: Melatonin can activate certain parts of the immune system. Although the significance of this effect is not yet clear, people with autoimmune disorders or taking immunosuppressive medications may want to avoid using melatonin.
Melatonin can cause side effects at higher doses, but is unlikely to cause a fatal overdose.
In adults, higher doses can cause uncomfortable side effects such as headaches and nausea.
Melatonin overdose in children is a growing concern, with hospitalizations increasing in recent years. However, this increase is largely due to the accidental ingestion of melatonin in children under 5 years old. Appropriate doses of melatonin for short-term use generally remain safe for children. But parents and caregivers should practice safe storage of all medications and supplements at home.
It’s also important to keep in mind that some melatonin supplements may not be labeled accurately. This increases the risk of taking a higher dose than expected. If you think you have taken too much melatonin, contact the poison control center for immediate, free expert advice.