Health Benefits of Melatonin

Melatonin is a hormone that tells your body it’s time to sleep. It is produced in an area in the brain called the pineal gland. Melatonin is commonly consumed in the form of a dietary supplement—a pill that you can find in the vitamin and supplement section of your local drugstore. 

Melatonin supplements can promote sleep and help people with sleep disorders but are only recommended for short-term use at this time.

Benefits of Melatonin 

Melatonin supplements are used as a natural sleep aid to help with sleep disorders, jet lag, delayed sleep-wake phase disorder, and even just to help you fall asleep and stay asleep.

Melatonin may have a role in treating other conditions, such as heart disorders, gastrointestinal conditions, mental disorders, neurodegenerative disorders (e.g., Alzheimer’s disease), and even cancer. However, research is currently ongoing. It’s too early to say whether melatonin can benefit these conditions.

May Help With Insomnia

When taken as a supplement, melatonin may help synchronize sleep-wake cycles (circadian rhythms) in people with insomnia. Insomnia is a common sleep disorder in which people struggle to fall asleep and stay asleep. Melatonin promotes sleep and mutes wake-prompting signals in the brain. This helps prevent waking up in the middle of the night, a common insomnia symptom.

However, research is mixed. A 2013 meta-analysis revealed that people with insomnia who took melatonin fell asleep seven minutes faster and stayed asleep eight minutes longer on average than people who took a placebo. Unfortunately, the doses used and the study quality varied greatly among the trials analyzed.

May Relieve Jet Lag

Jet lag is a temporary sleep problem that hits when you travel across multiple time zones. Quickly switching from one time zone to another creates a mismatch between your body’s sleep-wake cycle and the external environment. This mismatch may cause you to feel sleepy during daytime hours and awake during the night.  

Given melatonin’s sleep-promoting role, taking it as a supplement may help get your sleep-wake cycle back on track after traveling. A systematic review published in 2014 found that melatonin may be more effective than a placebo at reducing jet lag. It may also improve sleep quality.

However, the studies included in the review were older and low-quality. Newer, higher-quality research is needed to understand if and how melatonin can help with jet lag. 

May Treat Delayed Sleep-Wake Phase Disorder 

People with delayed sleep-wake phase disorder (DSWPD) have trouble falling asleep and waking up at times most others do. They typically prefer to wake up between 10 a.m. and 1 p.m. and feel sleepy between 2 and 6 a.m. Melatonin supplements may help people with DSWPD feel tired at the usual time.

In a 2018 study, people with DSWPD who took melatonin one hour before their desired bedtime saw improvements over four weeks. Improvements included falling asleep 34 minutes earlier on average and better daytime functioning.

A 2020 review reported similar findings in children with DSWPD. Researchers reviewed 19 randomized controlled trials involving 841 children. They found that melatonin helped kids fall asleep 22 to 60 minutes faster on average.

How to Take/Use Melatonin 

Melatonin supplements come in several forms, including liquid, gummies, chewable, capsules, and tablets.

As melatonin signals your body that it’s time to get ready for sleep, it’s best to take the supplement in the evening. Studies have administered melatonin up to two hours before bedtime.

Dosage 

There are no established dosing guidelines for melatonin, and the dose used in studies varies widely—from 0.1 to 10 milligrams (mg). Additionally, there’s no guarantee that the melatonin supplement you buy even contains the amount it says on the container. A 2023 study published in the Journal of the American Medical Association found that many melatonin gummies contain about 10% more melatonin than advertised, and some contained much more.

While lower doses (0.5 to 5 mg) are generally recommended for the treatment of insomnia and jet lag, it’s best to talk to your healthcare provider about what dose is safe for you to consume.

Is Melatonin Safe?

Short-term use of melatonin supplements appears to be safe for most people. However, there’s not enough information to support the long-term safety of melatonin supplements, especially when doses are higher than what the body produces naturally.

Melatonin is considered a dietary supplement—not a prescription or over-the-counter drug. That means it’s regulated less strictly by the U.S. Food and Drug Administration (FDA). Melatonin supplements may not contain what’s listed on the product label and/or contain other ingredients that may be harmful. For example, some supplements contain serotonin, a hormone that can have adverse effects at relatively low levels.

Some groups may need to take special care with melatonin supplements. In particular, children and older adults.

More families have turned to melatonin as a sleep aid in recent years. Melatonin supplements may contain other substances or varying amounts of melatonin, and there are no specific dosing guidelines for children. As such, kids and teens are at risk for melatonin poisoning. If you’re considering melatonin for your child, talk it over with your pediatrician or family physician first.

Melatonin may stay active in older people longer than younger people. This may cause daytime drowsiness, which can increase the risk of accidents. It’s also unclear whether melatonin supplements are safe for people who are pregnant or breastfeeding.

Potential Drug Interactions

As with all dietary supplements, melatonin may interact with other medications and supplements. These include:

• Blood thinners: Melatonin may enhance the effects of blood thinner medications (e.g., warfarin), increasing the risk of bleeding.
• Benzodiazepines: Melatonin may increase the sedative effects of depressants like benzodiazepines. 
• Fluvoxamine: This selective serotonin reuptake inhibitor (SSRI) (commonly used for depression and obsessive-compulsive disorder) may increase melatonin levels in the body. 
• Antibiotics: Certain antibiotics, such as quinolones, may increase melatonin levels. Meanwhile, rifampin may decrease melatonin. 
• Carbamazepine: This antiseizure drug may decrease melatonin levels in the body.

What to Look For

Dietary supplements like melatonin aren’t regulated by the FDA in the same way as prescription and over-the-counter drugs. This means you can’t be sure that the supplement you’re taking contains the ingredients listed on the product label or that it’s safe or effective.

However, choosing a supplement that’s been third-party verified may reduce your risk of adverse effects from an unsafe product. Third-party verification is when a manufacturer opts to have their supplements evaluated by an outside agency for quality and safety. Melatonin supplements that have been third-party verified typically list the name of the testing agency on the product label. Look for well-known agencies like ConsumerLab, NSF International, and U.S. Pharmacopeia (USP).

Can You Take Too Much Melatonin?

It’s possible to take too much melatonin, though the supplement isn’t considered poisonous even at large doses. In fact, the side effects of taking too much melatonin typically include sleepiness, headache, nausea, and agitation. In one case study from the National Capital Poison Center, a two-year-old boy who took up to 138 mg of melatonin recovered after sleeping a couple of hours.

Still, some people have been hospitalized after taking too much melatonin—4,097 over a 10-year period. Of those, 287 people needed intensive care.

Side Effects of Melatonin

Melatonin may have short-term side effects, including:

• Dizziness
• Headache
• Nausea
• Sleepiness

In children, melatonin supplements may also cause agitation and increased bedwetting or urination in the evening.

The long-term side effects of melatonin are unclear. Child and sleep experts say more research is needed to understand the safety of long-term melatonin use.

A Quick Review

Melatonin is a hormone that regulates your sleep-wake cycle. It’s often taken as a supplement to help with sleep issues like insomnia and jet lag. However, little is known about melatonin’s long-term safety and efficacy. Common side effects include dizziness, headache, nausea, and sleepiness. 

Older adults, children, people who are pregnant or breastfeeding, and those taking medications and other supplements should take special care with using melatonin. Always talk to your healthcare provider before adding a new supplement to your regimen.