Key Takeaways

• Melatonin is a hormone released in response to darkness or low light to help you fall asleep.
• More than 5 million adults in the United States take melatonin for sleep at least once monthly.
• Most adults who use melatonin for sleep take between 1–5 milligrams, though an increasing number are taking higher doses than recommended.
• The most common side effects of melatonin are daytime drowsiness, nausea, headache, and dizziness.

Many people in the United States don’t get enough rest each night, it’s no surprise that the use of melatonin for sleep has skyrocketed in recent years. As many as 5 million adults regularly reach for melatonin supplements to help with their sleep irregularities.

Sleep is essential to good health and influences everything from your mood to your weight to how well you fight off infections. While melatonin supplements may improve aspects of certain sleep disorders, they’re not suitable for everyone.

This article discusses everything you need to know about melatonin for sleep, including its benefits, potential side effects, recommended dosages, and alternative techniques to help you fall asleep at night.

What is melatonin?

Melatonin is a hormone produced by the pineal gland, a pea-sized gland located near the center of the brain. It’s most known for regulating sleep, though it also has anti-inflammatory and antioxidant properties that protect cells against damage.

Melatonin production starts with tryptophan, an essential amino acid found in dairy, eggs, fish, nuts, and seeds. The brain converts tryptophan to serotonin, which is eventually converted into melatonin.

Your body naturally produces melatonin to help you fall asleep, but melatonin is also produced in a lab and sold over the counter as a dietary supplement.

How does it work?

Melatonin regulates sleep through the body’s 24-hour internal clock, known as circadian rhythms.

The process begins in your eye’s retina. When light—including blue light from cellphones and computer screens—enters the retina, a signal is relayed to the brain’s suprachiasmatic nucleus (SCN). This triggers the release of cortisol and other hormones while suppressing melatonin production, which is needed to help you wake up refreshed.

When it begins to get dark, the SCN tells the pineal gland to release melatonin, which makes you feel sleepy. Melatonin production usually begins in the evening and peaks in the early morning before gradually decreasing.

Melatonin levels decrease as we age, starting around age 40. Research shows that by age 90, these levels may drop to less than 20% of what they were in young adulthood.

Several factors may contribute to age-associated melatonin production, including pineal gland calcification. This is a common condition that occurs when calcium deposits build up and harden, impairing the gland’s melatonin production.

Lifestyle factors such as working a night shift or exposure to blue light from electronic devices can also suppress melatonin release.

Decreased melatonin levels have been linked with the following chronic diseases:

• Alzheimer’s disease and dementia
• Type 2 diabetes
• Depressive disorders
• Rheumatoid arthritis
• Certain types of cancer

How to take it

In the United States, melatonin supplements are available over the counter at pharmacies and health food stores. They come in various formats, including chewable tablets, pills or capsules, gummies, and liquid tinctures, with both immediate- and extended-release options.

Melatonin supplements generally provide more than the 0.1–0.9 milligrams produced by the body daily, with doses ranging from 1–10 milligrams. 

There are no set dosing guidelines, but most experts recommend starting with a small dose that resembles the body’s natural melatonin production and using an immediate-release formulation.

The American Academy of Sleep Medicine (AASM) says lower doses may be just as effective as higher doses, and the timing—typically within an hour before bedtime—may be more important.

Most adults take less than 5 milligrams of melatonin at a time, according to data from a recent National Health and Nutrition Examination Survey (NHANES). Yet the prevalence of high-dose melatonin supplementation for adults—more than 5 milligrams—has steadily increased since 2005.

Benefits of melatonin for sleep

Melatonin supplements work best for sleep disorders related to your body’s internal clock, including jet lag, shift work disorder, and delayed sleep-wake phase disorder. There is limited evidence that melatonin may also help lessen anxiety when taken before surgery.

Jet lag

Several studies have noted that melatonin supplements can help prevent or reduce symptoms of jet lag, typically triggered by long-distance travel across multiple time zones, by helping your circadian rhythms adapt to the new time zone.

Anyone can experience jet lag, though older adults are likely to experience jet lag more intensely and take longer to recover than younger people.

Melatonin is most effective for easing jet lag when taken a few hours before your intended bedtime at your destination for several days once you arrive. 

Shift work

A recent research review found that melatonin supplements may improve daytime sleepiness, attention, time to fall asleep, and sleep quality in people with shift work disorder. The disorder affects adults who work nontraditional hours, including early-morning shifts, night shifts, and rotating shifts. It’s characterized by sleep deprivation, which can lead to excessive fatigue during working hours, poor mood, and difficulty concentrating.

If you decide to try melatonin for shift work disorder, take it after the end of your shift, once you get home, before your desired bedtime. Never take melatonin supplements before or during your drive home.

Delayed sleep-wake phase

People with delayed sleep-wake phase disorder (DSWPD), sometimes referred to as “night owls,” experience difficulty falling asleep and waking up. They typically go to bed later and wake up later. DSWPD is more common in young adults and adolescents and occurs when sleep patterns are delayed by at least two hours from typical patterns.

Taking melatonin before bed may help you fall asleep earlier if you have DSWPD. Yet the overall benefits versus potential risks for this condition need more research. In 2015, the AASM gave a weak recommendation for melatonin to treat delayed sleep-wake phase disorder.

A small review found that melatonin shortened the time it took people with DSWPD to fall asleep by about 22 minutes compared to the placebo. Another study showed that pairing melatonin an hour before bed with a set sleep schedule reduced the time it took to fall asleep by 34 minutes and improved daytime functioning.

Delayed sleep-wake phase disorder shares many of the same symptoms as insomnia, but the two are managed differently. 

Insomnia is a sleep disorder that occurs independently and is not linked to another sleep disorder. It may be caused by other medical conditions, including depression, restless leg syndrome (RLS), pain, or dementia. There is no solid evidence suggesting the benefits of melatonin for sleep in a person with chronic insomnia. 

If you think you may have delayed sleep-wake phase disorder, consult your doctor for diagnosis and treatment options.

Surgery-induced anxiety

If you’re one of 80% of people who experience anxiety before surgery, melatonin may be beneficial.

A 2020 review found that taking melatonin supplements before surgery can significantly reduce anxiety compared to a placebo, but there is little to no research supporting the effectiveness of melatonin supplements for treating insomnia caused by anxiety.

Potential side effects and risks of melatonin

Melatonin in low to moderate doses of 5 milligrams or less is considered generally safe for short-term use, but the long-term side effects need more research.

The following mild side effects have been reported with melatonin use:

• Daytime sleepiness
• Headaches
• Nausea
• Dizziness

Some people also report vivid dreams when taking melatonin supplements, meaning their dreams feel very real or lifelike. Side effects may be more intense with higher doses.

Melatonin can cause drowsiness, so you should avoid driving or using machinery for up to five hours after taking it.

People who are pregnant or trying to become pregnant should avoid melatonin supplements because there is not enough research on side effects. Current guidelines also advise against melatonin use in people with a dementia diagnosis.

Medication interactions

Melatonin can potentially increase or decrease the effectiveness of certain medications. Talk to your pharmacist or health care provider before taking melatonin if you’re prescribed any of the following:

• Blood thinners
• Medications used to treat seizures
• Diabetes medications
• Transplant medications that suppress your immune system
• Blood pressure medications
• Sedatives
• Birth control pills

For instance, melatonin may slow blood clotting and increase the risk of bleeding or bruising when combined with blood-thinning medications.

Caffeine may increase or decrease melatonin levels and potentially change the effects of melatonin supplements.

Other considerations

In the United States, Melatonin is considered a dietary supplement, so the Food and Drug Administration (FDA) doesn’t regulate it like prescription and over-the-counter medications.

A study that examined the melatonin content of 31 supplements found the ingredients in most supplements didn’t match their label, with some containing as much as 478% more melatonin than advertised. Researchers also found that 26% of the supplements contained serotonin, a hormone that is not authorized for sale as a supplement.

Choosing a supplement tested by a reputable third-party organization such as ConsumerLab, NSF International, or U.S. Pharmacopeia (USP) can help you identify whether the ingredients are accurate and safe.

Alternatives for improving sleep without melatonin

If you’re unsure about melatonin supplements or prefer more natural therapies, the following sleep hygiene practices may help improve your sleep quality:

• Establish a consistent sleep schedule by waking up and going to bed at the same time each day.
• Aim to get seven to nine hours of sleep each night.
• Keep your bedroom quiet and at a cool temperature for sleep.
• Avoid eating a heavy meal or drinking alcohol close to bedtime.
• Limit your exposure to bright light several hours before bed.
• Use your bed only for sleep and sex.
• Eat a well-balanced diet and incorporate at least 30 minutes of moderate-intensity exercise five days per week.
• Stop consuming caffeine at least six hours before bed.
• Turn off the TV, other electronic devices, and stop using your cell phone at least 30 minutes before bed.
• If you cannot fall asleep within 20 minutes, get out of bed and do a quiet activity, such as reading in low light, until you begin to feel sleepy.

You can also improve your sleep environment by choosing the best mattress to accommodate your health needs and preferred sleep position. 

For example, choosing a mattress that eases back pain may help decrease discomfort, while a mattress designed for side sleepers can help maintain spinal alignment for a more comfortable night’s sleep.

Mindfulness techniques, including meditation, yoga, and breathing exercises, can improve sleep by calming your mind and emotions. A review of randomized controlled trials found regular mindfulness interventions significantly improveed sleep quality.

CBT for insomnia

Cognitive behavioral therapy for insomnia (CBT-I) is often recommended as a first-line treatment for chronic insomnia and can produce results similar to sleep aids. 

A 2015 review found that CBT-I helped adults with insomnia fall asleep 19 minutes faster and reduced periods of wakefulness after falling asleep by 26 minutes. Total sleep time improved by 8 minutes, and sleep efficiency improved by 10%.

CBT-I focuses on learning new techniques to help change your thoughts and behaviors that may contribute to insomnia. Many online therapy services provide CBT-I.

Bottom line

Melatonin is a hormone that helps regulate the body’s sleep-wake cycle. It is generally considered safe to take melatonin supplements for sleep, and they may help with sleep disorders, especially jet lag and delayed sleep-wake phase disorder. Current research does not support the routine use of melatonin to treat chronic insomnia related to a non-sleep-related health condition.

If you’d prefer to avoid relying on melatonin supplements, consider alternative treatments, including cognitive behavioral therapy, establishing a good sleep routine, and practicing mindfulness techniques, for a better night’s sleep.

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