Melatonin dosage: how much should you take?

You’re about to take a long flight to a different time zone, and you’re worried about jet lag. Or, maybe you’ve been struggling with sleeping poorly for the past few months. These are just a couple of the scenarios where you might come across melatonin as a possible solution. 

The hormone melatonin is a common supplement used to help treat sleeping problems, including insomnia, jet lag, shift work disorders, and other sleep disturbances. 

But what about melatonin dosage? As a dietary supplement, there aren’t any official dosing guidelines, so it can be confusing to figure this out. 

Here are some suggestions for the melatonin dosages you might take according to scientific research.

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Melatonin is a hormone naturally produced in your brain. Its best-known purpose is its role in helping you sleep better. You can also take additional melatonin as an over-the-counter dietary supplement to help regulate your sleep-wake cycle (Savage, 2021). 

The U.S. Food and Drug Administration (FDA) considers melatonin to be a dietary supplement, not a medication, so there are no official dosing guidelines for treating sleep disorders with melatonin. There are some broad guidelines you can follow, however. 

Adults

In most research studies conducted, the dosage tested in adults varied from 0.1 mg to 10 mg, given up to two hours before bedtime as a sleeping aid. No maximum dosage has been defined (Savage, 2021). It’s a good idea to start at a lower dose to see how melatonin affects you before increasing your dose. 

Older adults

Research suggests that older adults process melatonin supplements differently and the levels in the body can be harder to control. Seniors are more likely to experience side effects, particularly from controlled-release formulas (Vural, 2014).

The best dosage of melatonin for older adults hasn’t been established. Researchers suggest using the lowest dose of immediate-release melatonin possible for older adults. The recommended doses range from 0.3 mg to a maximum of 2 mg. These are typically given one hour before bedtime to mimic the normal melatonin cycle in the body and avoid prolonged, elevated blood melatonin levels. (Vural, 2014).

Children and teens

Melatonin can be helpful for particular sleep problems in children and teens, particularly those with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD). However, you should only try supplements after good sleep hygiene practices haven’t improved sleep (Cummings, 2012).

While there have been some randomized, placebo-controlled trials of melatonin for children and teens, they have typically been limited by being short in duration or not having many participants. So we aren’t entirely sure how safe and effective long-term treatment with melatonin is for the pediatric population. There has also been some conflicting research about whether using melatonin may delay the start of puberty (Cummings, 2012). Before trying melatonin with a child, it’s best to speak to their healthcare provider first.

Your body makes natural melatonin by transforming the amino acid tryptophan into the neurotransmitter serotonin. Some of that serotonin makes its way to the pineal gland in your brain, where it turns into melatonin (Savage, 2021).

How much melatonin your brain makes depends on the information it’s getting about the level of light transmitted by the retinas in your eyes. Your body produces more melatonin in the evening as the light dims and you move towards your traditional sleep time (Savage, 2021).

This system is dependent on external cues such as light. So any disruptions in the amount of light present or your body’s ability to sense it can throw your body’s melatonin production off, leaving you without enough melatonin and affecting your levels of sleepiness (Savage, 2021).

Human and animal studies show that the short-term use of melatonin is safe and causes no serious adverse effects. Even long-term use in adults only shows mild side effects compared to placebo treatments (Andersen, 2016).

Taking too much melatonin may make you feel ill, but it is unlikely to be fatal or cause you any permanent injuries. In experimental research studies, scientists could not find a lethal dose of melatonin. Also, very large doses have been given to pregnant rats in research studies without any increased risk of death or injury to the offspring observed. We don’t know how this translates to humans, though, so pregnant people should not take melatonin without speaking to their healthcare provider (Andersen, 2016).

Higher doses of melatonin can cause some minor adverse reactions, such as (Savage, 2021):

• Headache

• Insomnia

• Rash

• Irritated stomach

• Nightmares

If you experience any of the following symptoms, call 911 and seek emergency help:

• Trouble breathing

• Sudden chest pain

• Blood pressure that’s over 180/120 mmHg

These aren’t typically signs of a reaction to or drug interaction related to melatonin. They are serious signs of a medical emergency, though, and shouldn’t be ignored.

If you think you may have overdosed on melatonin or any other substance, contact Poison Control either by phone or online. This is a free, confidential service that is available 24/7.

All medications and supplements have some risk of side effects. Melatonin is considered relatively safe and non-toxic overall. However, some mild side effects have been reported. These are most likely to occur with high doses of melatonin or with a controlled-release formulation (Savage, 2021).

The most commonly reported side effects of melatonin include (Savage, 2021):

• Drowsiness the next day

• Changes in blood pressure causing dizziness

• Headaches

• Nausea

Certain groups of people should avoid taking melatonin supplements. These include people who are pregnant or breastfeeding since we don’t have safety studies for this group. You also shouldn’t take melatonin if you are already taking other sedating medicines (Savage, 2021).

Other types of people should be cautious and talk to their healthcare provider before using melatonin for insomnia. These include people who (Savage, 2021):

• Are on dialysis for kidney disease

• Have impaired liver functioning

• Have an autoimmune condition

• Have had an organ transplant

• Are on immunosuppressant medicines

• Are children or teens

One other concern with melatonin supplements is that because the FDA doesn’t formally regulate over-the-counter melatonin, there may be significant variations in the amount of melatonin present in the pills. An analysis of 31 melatonin supplements found that the melatonin content was more than 10% above or below the labeled amount in more than 71% of the products tested. You can help protect yourself from getting more or less melatonin than you need by buying a high-quality brand (Erland, 2017).

You shouldn’t mix melatonin with other sedatives. This can lead to feeling excessively sleepy. Some examples include (Savage, 2021):

• Clonazepam (Klonopin)

• Lorazepam (Ativan)

• Alprazolam (Xanax)

• Alcohol

You also shouldn’t take your melatonin dosage with caffeine, as this can counteract the effects (Savage, 2021).

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How we reviewed this article

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.

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Current version

November 04, 2021

Written by

Ellyn Vohnoutka, BSN, RN

Fact checked by

Steve Silvestro, MD

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About the medical reviewer

Steve Silvestro, MD, Ro

Dr. Steve Silvestro is a board-certified pediatrician and Associate Director, Clinical Content & Education at Ro.