Melatonin Overdose

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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.

Related News

• Adding Melatonin to Anti-Seizure Treatment Can Reduce Symptoms and Improve Sleep QualityJanuary 1, 2023 – Adults with epilepsy who received melatonin as part of their treatment protocol had less severe seizures and improved sleep quality.
• Melatonin May Be Helpful for People with Insomnia Receiving Inpatient CareDecember 29, 2022 – A study found that small doses of melatonin before sleep may be effective for individuals in inpatient facilities experiencing persistent insomnia after non-pharmacological interventions.
• Melatonin May Safely Induce Sleep for Children Undergoing Sleep EEG
• Children and Adolescents With Chronic Insomnia May Benefit From MelatoninListed news articles do not represent the opinion of Sleep Foundation and are provided for informational purposes only.

Melatonin Overdose

Melatonin is a hormone that your body makes. It helps you sleep at night. It also comes in an over-the-counter dietary supplement for sleep for adults and kids as pills, creams, gargles, or gels. If you use it for short periods, melatonin should be safe. But experts still have a lot to understand about the supplement. In some situations, a melatonin overdose is possible.

It’s important to understand how to use the sleep aid safely. You should also be aware of the signs of a melatonin overdose.

What Are the Recommended Doses of Melatonin?

You can legally buy melatonin in any amount. You don’t need a prescription in the United States. But you can’t get melatonin over the counter in countries like Japan, Australia, the United Kingdom, and some parts of the European Union.

So far, experts haven’t come up with a specific dose or timing for the supplement to help insomnia. Many studies look at doses from 0.1 to 10 milligrams of melatonin. But doctors believe that 2 to 3 milligrams are usually a good amount to start with.

If you’re an adult, you can usually take up to 8 milligrams per day for about 6 months. For kids, experts suggest about 3 milligrams daily for 3 months.

It’s tough to tell exactly how much melatonin each person should take. Everyone’s body may react differently to the supplement based on their:

• Age
• Gender
• Sleep issues
• Health conditions
• Timing when they take melatonin

Studies have also found that sleep aid products may have more or less of the listed melatonin amount. Experts found that certain supplements may have anywhere from under 83% to over 478% of what’s listed on the bottle label. This may mean that you’ve taken more or less of the amount you believe you took. The reason for the poor quality control is that melatonin is considered a dietary supplement. This means that it’s not regulated by the FDA for its indication, potency, or purity.

What Are the Symptoms of a Melatonin Overdose?

Too much melatonin can lead to unwanted side effects. But it’s very rare that an overdose of the supplement could kill you. Each form of medication has a lethal dose, or LD 50. This term refers to the amount of supplement that would cause 50% of people to die. Experts haven’t been able to find an LD 50 for melatonin. Very high doses of melatonin weren’t even fatal in animals.

Common melatonin side effects include:

• Headache
• Dizziness
• Nausea
• Drowsiness

If you take too much melatonin, you might have less common symptoms. These include:

• Short-lasting depression
• Mild anxiety
• Tremors
• Stomach cramps
• Irritability
• Less of an ability to be alert
• Confusion or disorientation
• Very low blood pressure

If you take certain medications, you could be at risk of a melatonin interaction. The sleep aid won’t mix well with:

• Anticonvulsants (drugs to treat seizures)
• Anticoagulants and anti-platelet drugs (drugs to prevent blood clots)
• Contraceptive (birth control) drugs
• Diabetes medications
• Immunosuppressants (medications that suppress your immune system)

If you want to start melatonin supplements, ask your doctor first. They can tell you if you’re on any medications that would interact with the sleep aid.

Melatonin can affect your cardiovascular, dermatologic (related to your skin), and central nervous systems. If you have a condition related to one or more of these, you might be at risk of other side effects if you take melatonin.

In addition, if you are older, you may be more sensitive to the supplement. This is because you have a naturally low level of melatonin. So your doctor may suggest that you start with a lower amount of melatonin.

You can also have an allergic reaction to melatonin, but this is rare. In some cases, people may have anaphylaxis, which is a life-threatening allergic reaction, after they use melatonin.

Other signs of an allergic reaction to melatonin may include:

• A skin rash that may have itchy, red, swollen, blistered, or peeling skin
• Wheezing
• Tightness in your chest or throat
• Trouble breathing or talking
• A swollen mouth, face, lips, tongue, or throat

If this happens, you may need to visit the emergency room to get treatment right away.

What Can You Expect With a Melatonin Overdose?

If you think you’ve taken too much melatonin and begin to have unwanted side effects, don’t worry. Compared to other sleep supplements and medications, melatonin moves through your body very fast. Because of this, its effects don’t last very long.

If you develop slight side effects, try to wait it out a bit and let your body fully process the supplement.

But if the symptoms become strong or you feel concerned, it might be a good idea to call your doctor or poison control at (800) 222-1222. They can help you find the next step or guide you through certain symptoms.

If your child has taken too much melatonin, first make sure that they no longer have access to the supplement. Then, wipe their mouth out with a soft, wet cloth. Don’t try to make them throw up the melatonin that they took.

Afterward, call poison control right away. They’ll help you figure out your treatment options based on how much melatonin your child took.

How Can You Get Help for a Melatonin Overdose?

If you think you’ve overdosed from melatonin or are having an allergic reaction to the supplement, call your doctor, 911, or poison control right away. While it’s rare to have issues with melatonin supplements, it’s better to be cautious if you notice strange side effects from the sleep aid.

Show Sources

CDC: “Pediatric Melatonin Ingestions – United States, 2012-2021.”

National Capital Poison Control: “Melatonin Potential Uses and Benefits.”

St. Luke’s Health: “5 Harmful Medication Interactions You Need to Know.”

Sleep Foundation: “Melatonin Overdose.”

Medline Plus: “Melatonin.”

Sleep Advisor: “Can You Overdose on Melatonin? How Much Should You Take?”

Mayo Clinic: “Is Melatonin a Helpful Sleep Aid — and What Should I Know About Melatonin Side Effects?”

Missouri Poison Center: “Melatonin.”