Can Adults Overdose on Melatonin? How Much Should You Take? Editorial Team

Woman taking melatonin before sleeping

Yes. It is very possible to overdose on melatonin. Although a melatonin overdose is not likely, you should always be careful of how much to take. A good dose of melatonin is 0.5mg to 5mg as needed. However, if you’re finding that is not enough, you can experiment with taking a bit more, but speak to your doctor before going overboard. 

Here’s what you can expect to learn throughout this article:

What Is Melatonin?

Melatonin is a hormone the human brain and other mammals produce during nighttime hours. Melatonin plays a crucial role in one’s ability to sleep and contributes to circadian rhythms essential for behavior during a 24-hour day cycle.

If a circadian rhythm is disrupted, the brain may have difficulty producing melatonin, so synthetic melatonin was made for people who struggle with sleep disorders. 

Melatonin is used by people who have difficulty sleeping or have a sleeping disorder such as insomnia. Melatonin should never be used if you’re someone who has no issues with falling and staying asleep.

Although synthetic melatonin is considered natural, it doesn’t mean that it’s safe. Like most sleep medications, it has side effects.

People who struggle with going to sleep at a desired time or “night owls” often opt for a melatonin supplement or take a sleepy time tea to help them rest. However, insomniacs and narcolepsy sufferers use prescription medication to help them sleep.

Can You Overdose on Melatonin?

There is not sufficient evidence that states you can overdose on melatonin. However, three case studies reported people were admitted to the emergency room for a high dosage of melatonin in the years 2000 and 2001.

According to poison control, melatonin is safe when taken in small doses as needed – but not to be used as a long-term solution. 

Signs of Melatonin Deficiency

If you are someone who struggles to fall asleep or stay asleep through the night, one of the first signs a doctor will look at is a melatonin deficiency. However, melatonin deficiency often gets missed because many signs point to other sleep issues, such as chronic fatigue syndrome. 

Some signs that you may be melatonin deficient include:

  • Have restless leg syndrome – usually happens at night when your body finds it hard to relax, so you feel tense and constricted muscles, resulting in the urge to move your legs.
  • Problems with sleeping and sleep disturbances – If you’re a light sleeper, don’t have many dreams, find it difficult to fall asleep, and suffer from insomnia, you may have a melatonin deficiency.
  • Sudden mood changes – A melatonin deficiency may contribute to having feelings of anxiety or depression. One minute you may seem fine and happy, and the next, the world is ending with an uncontrollable desire to lash out or be destructive. 
  • Low thyroid problems – The thyroid hormone gives you energy and generates heat. If you’re feeling low energy and seem to be cold, a melatonin deficiency may be the problem.

Melatonin Side Effects

An overdose on melatonin can result in unwanted side effects, such as:

  • Extreme headache
  • Low or high blood sugar
  • Extreme fatigue and drowsiness
  • Disorientation and confusion
  • Vomiting or nausea
  • Weird dreams or nightmares
  • Brain fog
  • Stomach pain
  • Mild tremors
  • Panic and irritability

Melatonin is safe in low doses and as needed until better options come available. In safe doses, melatonin rarely has side effects. Although melatonin has many overdose side effects, it is normal to feel:

  • Drowsy (less intense than an overdose)
  • Upset stomach (no pain)
  • Dizziness (slight alteration of balance due to synthetic hormones)
  • Slight headache.

The above symptoms help your brain relax and will disappear naturally the more you take melatonin. Although melatonin is not proven to be addictive, someone who finds melatonin helps may become psychologically dependent. 

While it’s always best to check in with a doctor before taking any synthetic or prescription drug, many wonder, “how much melatonin should I take?” 

Melatonin is sold in doses of 1 to 10mg or more. Many people believe the higher dose they take, the better their sleep will be. This couldn’t be further from the truth. Higher doses may contribute to an overdose. So, the recommended amount varies from one individual to the next.

Depending on your natural melatonin levels, your age, weight, and other factors will determine how much you should take. Always discuss with your doctor before taking any synthetic hormone or natural supplement. 

How Much Melatonin Is Too Much?

As mentioned, too much melatonin can result in an overdose, but how much is too much? Since few studies state whether melatonin is safe, taking it as a sleep aid is going to be an experimental process. 

Your safest bet is to start with the smallest dose of melatonin and gradually increase as you need. When you hit the amount that gives you a good night’s sleep and helps you fall asleep quicker than usual, you have found the right amount for you. 

What Are Some Things That May Interact With Melatonin?

If you take other natural supplements or prescription drugs, you must always check with your doctor to know if melatonin is safe. Otherwise, the synthetic melatonin may interact with the other drugs you are taking. 

Interactions may include:

  • Birth control
  • Blood thinners
  • Blood pressure pills
  • Steroids
  • Diabetes medication
  • Anti-depressants or anti-anxiety medication
  • Seizure reducing medication

When to See a Doctor

Safety always comes first when it comes to your health. To ensure you get the proper dosage in order to prevent a melatonin overdose, you must speak with your doctor before taking melatonin and a couple weeks after starting the synthetic hormone. 

If you experience any unusual or uncomfortable signs, or if you’re taking any other medications such as the ones listed above, you should let your doctor know.

 Other reasons you should see a doctor for taking melatonin are if:

  • You’re giving it to a child
  • You’re pregnant or breastfeeding
  • People with epilepsy or are prone to seizures
  • Dementia patients
  • Shift workers
  • People who struggle with mental health disorders such as anxiety and depression. 


Some common questions many people ask about melatonin are as follows:

What time should I take melatonin?

Melatonin should be taken in small doses one to two hours before you intend to sleep. Since your brain naturally produces melatonin around an hour before you fall asleep, melatonin is best roughly two hours prior.

Are some people allergic to melatonin?

It is possible to be allergic to synthetic melatonin. Allergy symptoms include rashes, hives, face, and lip swelling, and constricted airways. 

What are the long-term effects of taking melatonin?

It has been known that people who suffer from sleep disorders have taken melatonin for up to two years or more. Taking any synthetic hormone will automatically increase the hormone produced in your brain up to 20 times more than normal. 

Long-term effects may cause oversleeping, sleeping more than expected, chronic headaches, and balance issues. 

Where should I store melatonin?

Melatonin should be easily accessible to adults only – keep it out of reach from children. The supplements should be stored in a dry place at room temperature. Hot, humid, or cold places will affect the drug’s desired effects. 

Is melatonin safe for children?

Melatonin is safe for children in smaller doses than for adults. When used specifically for children, there are little to no side effects as directed by a doctor. 

Although, children rarely need melatonin. If you are concerned about your child’s sleeping patterns or habits, speak to a pediatrician, as there may be underlying causes. 

Is melatonin safe to take everyday?

It has not been scientifically researched that melatonin is safe for long-term use, so to stay on the safe side, stick to no longer than three months of taking melatonin. 

What are some natural sources of melatonin?

You can find small traces of natural melatonin in fruits and vegetables, such as:

  • Cherries
  • Corn
  • Asparagus
  • Olives
  • Tomatoes
  • Pomegranate
  • Broccoli
  • Bananas
  • Cucumber
  • Ginger
  • Radishes
  • Red Wine
  • Grapes
  • Raisins
  • Sunflower Seeds
  • Barley
  • Rice
  • Peanuts

Bottom Line: Can You Overdose on Melatonin for Adults?

Yes, it is possible to overdose on melatonin. If you suspect you are experiencing melatonin overdose or know someone who might be, the first thing you need to do is call poison control. They will ensure you and your friend’s safety and give you guidance on what to do next. 

If you are suffering from sudden chest pain, shortness of breath, or extremely high blood pressure, call an ambulance immediately, as they may be signs that are interacting with other medication you could be taking. 

While melatonin is generally safe to take in small doses or as directed by your doctor, more natural and safer methods are recommended to try first through fruit and vegetables. 

If warm baths, meditation, and prescription drugs are still unable to help you fall asleep, you may need to see a sleep specialist to rule out underlying causes.

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