Can Adults Overdose on Melatonin?

Can Adults Overdose on Melatonin?
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You just got done working the late shift and have to be up early tomorrow morning. But you just can’t seem to fall asleep. And this isn’t the first time your work schedule has interfered with your sleep schedule. You’ve thought about taking over-the-counter (OTC) sleep aids or calling your healthcare provider about prescription sleep aids. But maybe you’d rather take something like melatonin to help you get to sleep.

Melatonin is naturally made inside the body, but there are still risks associated with taking melatonin supplements. It seems to be safe for sleep when taken for shorter lengths of time. But it’s still not clear about the safety of taking it long-term. And high doses can lead to side effects. So, what dose of melatonin is right for you, and how much is too much? Can you overdose on melatonin?

Below, we’ll discuss melatonin dosing for adults, symptoms of taking too much melatonin, and what to do if you think you’ve taken too much.

What does melatonin do to the body?

Melatonin is a hormone that your brain naturally makes to help control your sleep-wake cycle. You release more melatonin at night to let your body know it’s time for sleep. In fact, your brain releases 10 times more melatonin at night than it does during the day.

Even small amounts of light, such as from a smartphone or laptop, can cause your body to make less melatonin. A drop in melatonin levels may signal your body to stay awake, even at night. You may have trouble sleeping because of low melatonin levels.

Is it possible to overdose on melatonin?

In short: no. There’s no good evidence that taking too much melatonin can lead to a life-threatening overdose the way other sedating drugs can. Case reports of serious health complications in adults after a high intake of melatonin have occurred when the substance is combined with sedating medications or substances, like alcohol. But even though there’s no current evidence to suggest that high doses are fatal, that doesn’t mean melatonin is free of side effects.

What are the symptoms of taking a high dose of melatonin?

When taking melatonin supplements, it’s important to know the possible side effects that can occur. The following may occur if someone’s taken too much melatonin:

  • Headache
  • Nausea
  • Drowsiness
  • Irritability
  • Dizziness


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Is it OK to sleep if I’m feeling side effects from too much melatonin?

If you feel like you have taken too much melatonin, you may feel drowsy, and it may be difficult to stay awake. According to Poison Control, it’s OK to sleep if you’ve taken a high dose of melatonin. But you should only sleep if the following three steps are also followed:

An adult should stay with you until you’re fully rested and awake.

The adult staying with you should try to wake you up every 30 minutes while you’re sleeping.

If your breathing becomes irregular or you’re unable to wake up, 911 should be called, or you should be taken to the nearest emergency room.

If you’re concerned about the amount of melatonin you took, contact Poison Control. (1-800-268-9017)

How long does melatonin last in the body?

Melatonin’s effects can last several hours. It takes your body 1 to 2 hours to get rid of half the amount of melatonin you take. This is called the half-life. Most people won’t feel melatonin’s effects after this point. But a medication or substance takes much longer than this to be fully cleared from the body. So, some people may continue feeling the effects of melatonin for longer than this.

How much melatonin is safe to take?

Melatonin supplements are available in a wide range of strengths. Most adults who use it take 5 mg or less per day. But more studies would be needed to say what doses are ideal. As a general rule, it’s best to start with the lowest dose first. If this isn’t effective, try a slightly larger dose one step at a time to see how it affects you.

Dietary supplements, such as melatonin, aren’t regulated by the FDA in the same way as prescription and OTC medications. Melatonin supplement products aren’t required to go through safety and efficacy testing. And the amount of melatonin in each product can vary.

For instance, a study of various melatonin products showed that 71% of melatonin supplements tested contained different amounts of melatonin than those listed on the label. Some melatonin supplements were even found to contain other substances, such as serotonin.

With a wide range of doses and products available, it’s important to be careful when taking melatonin supplements. It’s also a good idea to discuss using melatonin with your healthcare provider first. They may be able to recommend certain brands of melatonin supplements they trust as well as an ideal starting dose for you.

Typical dosing of melatonin

The typical dosing for melatonin is 1mg, 3mg, or 5mg. Adults shouldn’t take more than 8 mg by mouth daily for up to 6 months. Doses are usually taken within 2 hours before bedtime.

Melatonin use in children is even less studied than it is for adults. There’s also concern that this supplement may be more dangerous for kids. Speak to your child’s healthcare provider if they’re having trouble sleeping. They can recommend a treatment option based on your child’s age and medical conditions.

When should I seek medical attention for taking too much melatonin?

It’s important to know when to seek medical attention if someone took a high dose of melatonin. If a person who took too much melatonin also starts to have trouble breathing or you can’t wake them up, you should call 911 or go to the nearest emergency room. They may have also taken another medication or substance that’s causing these more serious symptoms.

Even if you don’t need urgent medical attention, it would also be a good idea to follow up with your primary care provider. They can help you find a better treatment for sleep difficulties.

In the end

Melatonin is an OTC dietary supplement that’s commonly used as a sleep aid. Some studies have been conducted on the use of melatonin for sleep. But studies on its safety and effectiveness are limited. There are also no clear dosing guidelines set by the FDA.

You should start melatonin at a low dose and continue to take the lowest dose that works for you. Taking high doses of melatonin can cause side effects, like drowsiness or nausea.

If you or someone you know is struggling with depression or has had thoughts of harming themselves or taking their own life, know that help is available. The National Suicide Prevention Lifeline (1.833.456.4566) provides 24/7, free, confidential support for people in distress, as well as best practices for professionals and resources to aid in prevention and crises.


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Written by Elizabeth Cambria, PharmD | Reviewed by Katie E. Golden, MD

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