Melatonin for sleep: is it effective?

last updated: Sep 08, 2021

4 min read

Many different dietary supplements and herbs are promoted as so-called natural sleep aids. But only one dietary supplement is a synthetic version of your body’s natural sleep hormone: melatonin. If you’re looking for a safe dietary supplement to help with sleep, read on to learn more about melatonin and its effectiveness for sleep. 


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What is melatonin?

Melatonin, also known as the “sleep hormone,” is a hormone naturally made in your brain. Melatonin plays a major role in regulating your body’s internal clock or circadian rhythm (Savage, 2021).

Melatonin is available over-the-counter as a dietary supplement. It contains synthetic (lab-created) melatonin. Because melatonin is a dietary supplement and not a drug, it isn’t approved or regulated by the Food and Drug Administration (FDA). According to the FDA, dietary supplements “are not intended to treat, diagnose, prevent, or cure diseases” (FDA, 2020).

Does melatonin work for sleep?

Some people feel that taking a melatonin supplement helps to improve their sleep. But, there’s limited scientific evidence to support melatonin use for insomnia—a sleep disorder in which you have trouble falling asleep or staying asleep.

Natural melatonin production occurs in the pineal gland in your brain. Melatonin gets released into your bloodstream in a daily pattern that typically starts in the evening in response to dim lighting. Levels of melatonin, sometimes called the darkness hormone, increase and peak while you sleep. But, exposure to bright light can slow or block melatonin release (Masters, 2014).

Meta-analysis researchers have reviewed the results from multiple clinical studies of melatonin supplementation in adults and children with sleep disorders. Their findings show that taking melatonin may slightly reduce the average time it takes to fall asleep by about seven minutes, increase total sleep time by about eight minutes, and improve overall sleep quality. And another analysis of clinical studies showed that melatonin supplements helped people fall asleep about 12 minutes sooner (Ferracioli-Oda, 2013; Buscemi, 2005). 

But, the consensus among experts is that a few extra minutes of sleep doesn't appear to make much of a difference in a person’s health. Overall, the American Academy of Sleep Medicine does not recommend melatonin as a treatment for chronic (long-term) insomnia because the available evidence to support its use is weak (AASM, 2021; Sateia, 2017).

However, other clinical evidence shows that melatonin supplements are particularly effective in people with certain health conditions or specific situations, such as (NCCIH, 2021):

  • Perioperative anxiety: anxiety that occurs just before a person undergoes surgery

  • Sleep disorders in children with eczema, asthma, ADHD, or autism spectrum disorder

  • Jet lag: the term used to describe symptoms such as sleepiness and headaches that occur as your body adjusts to a different time zone after traveling

  • Delayed sleep-wake phase disorder (DSP): occurs when a person’s circadian rhythm is delayed by two or more hours. People with DSP have trouble falling asleep and waking up at “normal” times. Instead, they prefer late bedtimes and late wake-up times, a sleep pattern that can be problematic with school, work, or family schedules.

  • Insomnia in older adults ages 65 years and older (Masters, 2014).

How much melatonin can you take?

There isn’t one standard or recommended dosage for melatonin. Most studies of melatonin for sleep disorders have used dosages ranging from 0.1 mg to 5 mg per day (Ferracioli-Oda, 2013).

Some studies have explored higher doses of melatonin for uses other than insomnia. For example, studies suggest that melatonin ranging from 3 to 10 mg safely provides anti-anxiety effects when administered to people 30 to 60 minutes before they undergo surgery—however, this data is limited (Andersen, 2014).

When you’re deciding how much melatonin to take, it’s best to start with a low dose, such as 0.1 mg to 1 mg. If you don’t notice any improvement within a few doses, you can try increasing the amount according to the product’s labeled instructions. 

The quality of dietary supplements can vary. To ensure that you’re selecting a high-quality melatonin supplement, look for a “USP Verified” mark on the product label. This means that the United States Pharmacopeial has tested the product and confirmed that the melatonin content is accurate and free from contaminants or hormones like serotonin. Quality testing of 31 different melatonin products found that 71% contained either significantly more or less melatonin content than the amount claimed on the product’s label (USP; n.d.; Erland, 2017). 

If you have questions about choosing a melatonin product or dosage that’s right for you, talk to a pharmacist or healthcare provider.

When should you take melatonin?

Some research suggests that the timing of melatonin supplements makes a difference in how well it works to help you fall asleep. If you take melatonin at bedtime, a higher dose may be necessary. But a lower dose may be effective if it’s taken two to four hours before bedtime. It’s important to follow the dosing instructions on over-the-counter product labels (Masters, 2014).  

Is melatonin safe to take every day?

Short-term use of melatonin seems to be safe. But, the long-term safety of melatonin supplements isn’t fully known due to the lack of study evidence.

Researchers analyzed the results from seven clinical studies that compared the use of melatonin to a placebo for sleep disorders. The most common side effects reported by people who took melatonin were headaches, dizziness, nausea, and drowsiness. However, the same side effects were also commonly reported by people who took a placebo (Buscemi, 2006).

A large, long-term clinical trial was conducted in older adults (ages 55 years and older) to compare a 2-mg extended-release melatonin supplement to a placebo. (A placebo is a treatment that contains no active ingredient). Participants reported no significant side effects during this six-month study, and reported no withdrawal effects after they stopped treatment (Wade, 2010).

Melatonin is not addictive, and overall, it seems to be a safer choice than most prescription sleep aids. But, taking melatonin for sleep is a decision that’s best made with a healthcare provider after discussing your symptoms, other medications, medical conditions, and health history.

Tips for getting better sleep

Many people can improve their sleep problems by making a few changes to their daily routines. Also known as having good sleep hygiene, adopting certain tips can help set you up for a good night's sleep. Some examples include (Krystal, 2019):

  • Avoid consuming caffeine, nicotine, and alcohol before bedtime, as these substances can disturb sleep.

  • Engage in a calming routine before bedtime that does not involve brightly lit screens which can keep you awake.

  • Ensure that your bedroom is a dark, quiet, cool environment.

  • Stick with a consistent bedtime and wake-up time, even on the weekends.

If you continue to struggle with trouble sleeping, it may be time to talk to a healthcare provider. They may check you for any underlying medical conditions that can cause insomnia or make it more severe. Non-drug therapy, such as cognitive behavioral therapy, is also recommended for chronic insomnia by the American Academy of Sleep Medicine (Sateia, 2017).

A healthcare provider can guide you on the right treatment plan to help you get the sleep you need.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

September 08, 2021

Written by

Patricia Weiser, PharmD

Fact checked by

Felix Gussone, MD

About the medical reviewer

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.