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Can You Overdose on Melatonin

Can You Overdose on Melatonin?

Danielle writes in-depth articles about sleep solutions and holds a psychology degree from the University of British Columbia.

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Medically Reviewed by

Dr. Abhinav Singh, Sleep Physician

Dr. Abhinav Singh

Dr. Singh is the Medical Director of the Indiana Sleep Center. His research and clinical practice focuses on the entire myriad of sleep disorders.

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Melatonin is a hormone that plays a significant role in the regulation of sleep and circadian rhythms. Dubbed the sleep hormone, melatonin is formed in the brain’s pineal gland in response to falling light levels to prepare the body for sleep.

In recent years, melatonin supplements marketed to treat a variety of sleep disorders have become common. From 2007 to 2012, melatonin use in the U.S. doubled Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference and it now ranks as one of the nation’s most popular supplements. Its popularity stems in part from its image as a natural alternative to traditional sleep medications, which are known for side effects. However, this does not mean melatonin supplements are harmless.

It is important to be aware of the safety risks posed by taking too much melatonin. We take a closer look at melatonin dosing, potential symptoms of a melatonin overdose, and when to contact a doctor.

How Much Melatonin Is Safe to Take?

Melatonin is available to purchase in any quantity, without a prescription in the U.S. However, there is currently no formal consensus on the optimal dosing regimen for this supplement. Studies frequently use doses ranging from 0.1 to 10 milligrams Trusted Source National Center for Biotechnology Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , but 1 to 5 milligrams is often considered an appropriate amount to start.

There are many challenges to determining the appropriate amount of melatonin for any one person to take. Individual responses to this supplement can vary considerably due to factors that are not fully understood but can include age, gender, specific sleep issues, other health conditions, and timing of administration.

In addition, not all melatonin supplements are created equal. Differences in preparation can significantly alter Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference melatonin’s impact. Depending on the formulation, taking 1 to 10 milligrams of melatonin can raise the body’s melatonin blood levels anywhere from 3 to 60 times the normal amount.

Melatonin users should also be wary of the dosages listed on supplement labels, which have shown to be alarmingly inaccurate. A random sampling Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference of 31 brands of melatonin supplements determined that most did not contain the labeled dose, with the actual amount ranging anywhere from less than 80% to nearly 500% as much. Additionally, over one quarter of the supplements contained serotonin.

Despite the lack of data and variability around dosing regimens, with typical use, melatonin is largely considered safe Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference and is generally well-tolerated in healthy adults. The risk of side effects Trusted Source National Center for Complementary and Integrative Health (NICCH) NCCIH funds and conducts research to help answer important scientific and public health questions about complementary health approaches. See Full Reference is low, but can include mild headache, dizziness, nausea, and sleepiness.

Finding Reputable Sleep Supplements

The safety and efficacy of supplements is not closely monitored by the U.S. Food and Drug Administration (FDA). Shoppers should take additional measures to make sure they are purchasing reputable products.

Can You Overdose on Melatonin?

So far, there is no clinical evidence that short-term melatonin use can cause long-term problems in healthy adults. However, it is important to discuss melatonin supplementation with your doctor, as they can help you determine the proper dosage. Starting with the lowest possible dose is typically recommended. This can help prevent unwanted side effects.

It is also important to note that high-quality studies addressing higher doses of melatonin are lacking. The current body of evidence consists mostly of small studies and case reports.

In one study, 12 adult males were administered intravenous melatonin Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference in doses of 10 milligrams, 100 milligrams, or a placebo. There were no reported differences in sedation among the groups, and there were no harmful reactions. A second study gave five patients 1,000 milligrams of oral melatonin Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference for approximately four weeks. While changes in pituitary hormones were observed, no toxic effects were reported.

What Are the Symptoms of a Melatonin Overdose?

Unwanted or troubling side effects can occur with any supplement, even if it is considered relatively safe. Concerning symptoms have been reported with higher doses of melatonin.

Possible symptoms of too much melatonin include:

Headache
Hypotension (low blood pressure)
Hypertension (high blood pressure)
Drowsiness
Vomiting
Worsening of alopecia areata (an autoimmune disorder causing hair loss)

Because melatonin can affect the cardiovascular, dermatologic, and central nervous systems, those with other conditions may be vulnerable to additional risks. Evidence suggests that melatonin supplementation may induce depression Trusted Source Merck Manual First published in 1899 as a small reference book for physicians and pharmacists, the Manual grew in size and scope to become one of the most widely used comprehensive medical resources for professionals and consumers. See Full Reference , particularly in people predisposed to or currently experiencing it. Research on this topic, however, is conflicting, since some studies have demonstrated the potential for melatonin to treat depression Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference .

People taking blood thinners and benzodiazepines should be careful, as there is a possibility for interaction Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference . Those with epilepsy should also exercise caution, as melatonin has been associated with increased seizures. People who are currently taking other medications or supplements should discuss potential interactions directly with their doctor before taking melatonin.

Research suggests that elderly people, who have lower natural levels of melatonin Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , may be more sensitive to the effects of melatonin supplements. Therefore, older people are encouraged to check with their doctor before taking melatonin and start with the lowest possible dose.

What Do I Do If I’m Experiencing Symptoms of a Melatonin Overdose?

Compared with most other sleep aids, melatonin clears the body quickly, and its effects are short-lasting. If you are experiencing unwanted symptoms after taking melatonin, you can most likely just wait it out as your body processes the drug. However, when in doubt, it’s always a good idea to seek professional advice. Don’t hesitate to contact your doctor or local poison control for guidance on managing worrisome symptoms or determining whether you need medical care.

What Are the Long-Term Effects of Taking Melatonin?

Minimal research exists on using melatonin beyond a few months. Therefore, there is much we do not know about its long-term effects. There is not even agreement on what constitutes long-term melatonin use.

Most of the concern around taking melatonin for extended periods centers around it’s potential to affect reproductive hormones. While the exact mechanism of action is still unclear, some reports indicate that melatonin may inhibit reproductive hormones Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference .

Is Melatonin Safe for Children?

Further research is needed regarding the safety of melatonin Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference for children.

Nearly 25% of children have difficulty sleeping Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , and parents increasingly turn to melatonin for help. Between 2007 and 2012, pediatric melatonin use rose seven-fold Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference and is now the second most common natural supplement in this age group.

Despite its prevalence, there are reasons for parents to be cautious about using melatonin. It appears that children may be particularly vulnerable to the possible effects of this supplement on reproductive hormones. Melatonin has been associated with puberty delays Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , irregular menstruation, and overproduction of the hormone prolactin. It is important to note, however, that research on this topic is conflicting Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , and experts agree that the topic is understudied.

Parents should also be aware that melatonin may decrease blood pressure or serum glucose levels Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference . Children taking other medications or who have illnesses affecting these systems should consult their doctor before starting melatonin.

Melatonin should only be used for children under the guidance of a doctor. Most pediatric sleep disorders can be managed with behavioral changes, such as proper sleep hygiene and cognitive therapy. Melatonin should not be used before trying other measures.

When Should I Talk With a Doctor?

While melatonin is largely viewed as safe, it is not without risk. Perhaps the most significant risk is what we do not know about this supplement. While you are unlikely to cause any serious damage using melatonin, it’s best to proceed with caution. Seeing a doctor for an accurate diagnosis of a sleep condition can help you determine whether melatonin is suitable for your situation.

Can You Overdose on Melatonin?

Angelica Bottaro is a writer with expertise in many facets of health including chronic disease, Lyme disease, nutrition as medicine, and supplementation.

Published on April 12, 2022

Gurdeep S. Sareen, PharmD, is a Director of Pharmacy and Population Health at CareMount Medical in New York.

Table of Contents
Table of Contents

Melatonin is a hormone that helps regulate sleep cycles. Although it is naturally produced by the body, it can also be taken in supplement form. When taken as a supplement, it is possible to overdose on melatonin.

This article discusses the uses, dosages, and side effects of melatonin, as well as the signs of an overdose.

What Is Melatonin Used For?

When a person’s sleep schedule becomes disrupted because of sleep disorders or jet lag, supplemental melatonin may be used to restore your sleep cycle and reregulate your body’s circadian rhythm . The circadian rhythm is the body’s 24-hour clock.

Other situations that may warrant melatonin use include those that may disrupt a person’s sleep schedule, such as shift work.

Melatonin’s Role in the Body

The naturally occurring type of melatonin is designed to aid in regulating your circadian rhythm. The hormone controls your sleep and wake cycles. When night falls, the brain receives the signal to start producing melatonin to ready the body for sleep.

However, because melatonin acts as an antioxidant, it also protects against certain cancers, as well as neurodegenerative disorders.

Melatonin Benefits

Melatonin can benefit you in a variety of ways, including:

Improving your sleep-wake cycle
Helping you fall asleep
Managing sleep disorders such as insomnia
Regulating the circadian cycle in people who are blind or work overnight
Preventing and treating jet lag
Preventing oxidation in the body, which can lead to inflammation, cell damage, and increase the risk of developing chronic diseases such as cancer
Aiding proper immune system functions by activating disease-fighting cells, known as natural killer cells and T lymphocytes
Decreasing your risk of developing neurodegenerative disorders such as Alzheimer’s disease

There continues to be debate about the effectiveness of taking melatonin supplements. More research is needed on the benefits and risks of long-term use.

Melatonin Side Effects

Occasional, short-term use of melatonin is considered generally safe. However, when a person chooses to take melatonin to help them sleep, they may experience some adverse effects. Side effects can include:

Is Melatonin Safe for Kids?

The Food and Drug Administration (FDA) hasn’t evaluated or approved the use of melatonin in children. There is also a lack of evidence surrounding any side effects involved in using melatonin at a young age. Because of this, you should always speak to your healthcare provider before giving your child melatonin.

Recommended Melatonin Dosage

The recommended dose of melatonin varies significantly depending on the person. This makes it difficult to determine how much you can safely use so that you don’t overdose or take too much.

Factors such as age need to be considered when determining your dose. The optimal dose by age is:

Infants: 1 milligram (mg)
Children: 2.5 to 3 mg
Adolescents: 5 mg
Adults: Anywhere between 0.5 and 5 mg
Older adults: Starting dose between 0.3 and 2 mg

Other factors such as weight and tolerance should also be taken into account when determining how much melatonin you can take.

Speak to your healthcare provider before starting melatonin. They will likely advise you to start at the lowest dose and work your way up if it is not working.

Uses of Melatonin

Typically, when someone wants to take a melatonin supplement, they are looking to correct their sleep pattern or get better and more restful sleep.

Research has shown that using melatonin for purposes aside from sleep is possible. One study looked at melatonin usage and anxiety prior to and following surgery and found that using melatonin prior to surgery helped reduce feelings of anxiety.

Long-Term Effects of Daily Melatonin Use

Using melatonin is typically only recommended on a short-term basis. Long-term use of the supplement can cause the brain to become desensitized to it, which makes the supplement less effective over time.

One study looked at long-term use of the supplement and found that in six to 12 months following the first use of the supplement, the positive benefits associated with short-term use were gone.

Not all long-term effects are negative, however. Some research has found that people who have recently gone through menopause may experience better symptom management from daily use of the supplement.

Age may also play a role in the long-term effects. Research has found that adolescents beginning melatonin use before the age of 12 and who used the supplement for just over seven years had normal sleep quality a decade later.

Where to Buy Melatonin

Melatonin can be purchased over the counter at any drugstore, pharmacy, or sometimes, grocery store. It is also available at specialty supplement stores. Prior to choosing a melatonin supplement, you should speak to your healthcare provider to find out what dose would be best for you, as well as where to look for the highest-quality supplement.

Signs of Melatonin Overdose

Taking too much melatonin is not more effective and can have the opposite effect. This means that the sleep hormone may actually make it harder to fall asleep if too much is in your system.

Symptoms of Melatonin Overdose

Taking too much melatonin can lead to symptoms such as:

Headache
Changes in blood pressure
Drowsiness
Vomiting

People who have naturally low levels of melatonin in the body, like older adults, may be more sensitive to symptoms and side effects.

Medications That Interact With Melatonin

When taking new supplements, it’s important to consider possible drug interactions that may occur with the medications you take regularly. People who are on blood thinners, benzodiazepines , or epilepsy medications should heed caution prior to starting a routine with melatonin.

This isn’t to say that you cannot take melatonin if you require these medications. However, you should be under close observation by your healthcare provider during your treatment using melatonin.

Drugs that lower blood pressure can also cause a drug interaction when taken with melatonin.

Melatonin and Adverse Effects

Although adverse effects are rare, they can occur. Allergic reactions, fatigue, mood changes, and worsened cognitive performance can all be driven by melatonin use. Melatonin has also been shown to affect blood pressure and heart rate.

What Happens When You Overdose on Melatonin?

While the clinical research surrounding melatonin overdose is limited, overdosing is possible even if it’s not likely to result in serious health complications. The symptoms can range in severity depending on how much is taken and how the person’s body responds to the dose.

Treating a Melatonin Overdose

The most effective, first-line treatment option for melatonin overdose is eliminating the supplement from your routine. This will rid the body of the overabundance of the hormone and ease symptoms.

If the symptoms are serious, you may have to see a healthcare provider immediately so they can assess your symptoms and determine necessary treatment.

When to See a Healthcare Provider

You should see your healthcare provider before on melatonin. A provider will determine how much you should be taking and which supplement to buy based on your optimal dose.

Your healthcare provider will also be aware of other medications you’re taking. So, if you do want to start taking melatonin, your provider can develop a safe plan to do so.

Melatonin and Emergency Medical Care

If you’re experiencing symptoms of an allergic reaction, shortness of breath, chest pain, or a rise in blood pressure after taking melatonin, you should seek emergency health services immediately.

Outlook

Struggling with sleep issues is difficult, and using melatonin is relatively safe and effective. However, there are some factors that need to be taken into consideration prior to beginning so that you don’t take too much of the supplement.

Since it’s possible to overdose, knowing how much to take and whether there are other things you can do to boost your melatonin production naturally may be a helpful alternative. This is especially true if you’re unsure as to whether the supplement will help you, or if you are unwilling to risk the side effects of taking melatonin.

Summary

Melatonin is a naturally produced hormone that regulates your sleep-wake cycle. It also plays a role in immune function and acts as an antioxidant in the body.

In supplement form, melatonin is often used to address sleep issues, such as insomnia, or restore a proper sleep cycle in people that experience jetlag or work shift work.

When taken at low doses, melatonin is safe and effective. However, there are some associated side effects, including headaches, dizziness, and nausea. Taking too much melatonin can lead to an overdose. When an overdose occurs, people may experience symptoms such as daytime sleepiness, vomiting, and high blood pressure.

In rare cases, serious health consequences can occur, but clinical research surrounding melatonin overdose is limited. To treat melatonin overdose, the first step is eliminating use so that it can be excreted from the body and relieve symptoms.

A Word From Verywell

Coping with sleep issues or changes in your sleep cycle can be challenging. Taking melatonin may be an effective way to restore your body’s ability to get good quality sleep. That said, you should follow the recommended dosage and watch for side effects to ensure that you don’t take too much. Always inform your healthcare provider before starting any new supplement regimen to ensure that it is safe for you.

Frequently Asked Questions

Can a melatonin overdose cause death?

Although it is possible to overdose on melatonin, researchers have not yet encountered a dose that would be lethal. There also are no reports of death caused by melatonin. Typically, melatonin overdoses present with mild to moderate symptoms that correct themselves when the melatonin use is stopped.

What happens when you mix melatonin and alcohol?

Taking melatonin and alcohol together is not advised. Alcohol is known to disrupt sleep patterns, which reduces the effectiveness of melatonin. In some cases, alcohol can also strengthen the effects of melatonin, leading to extreme drowsiness, dizziness, and an increased risk of accident or injury.

12 Sources

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By Angelica Bottaro
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.

Can You Overdose on Melatonin

Can You Overdose on Melatonin?

How Much Melatonin Is Safe to Take?

Can You Overdose on Melatonin?

What Are the Symptoms of a Melatonin Overdose?

What Do I Do If I’m Experiencing Symptoms of a Melatonin Overdose?

What Are the Long-Term Effects of Taking Melatonin?

Is Melatonin Safe for Children?

When Should I Talk With a Doctor?

Can You Overdose on Melatonin?