Can you overdose on melatonin?

Melatonin is popularly known as a sleep remedy. This supplement may be recommended if you are having trouble falling asleep either due to stress or because of certain health conditions such as diabetes.

The thing with this supplement is that while it’s easy to get it over the counter in the US (you can only get it through a doctor’s prescription in the UK), there isn’t a standard recommendable dosage. Secondly, it is not strictly regulated by the Food and Drug Administration (FDA). This means that these supplements may vary in strength from one manufacturer to the other.

It’s also important to note that since melatonin is excessively metabolized in the liver, older people will generally need a much lower dose than younger people because liver metabolism declines with age.

The lack of regulation of over-the-counter melatonin coupled with the varying strengths and the differences in liver metabolism is what has led to the confusion surrounding the use of this supplement.

Some of the grey areas regarding this supplement include the right dosage and whether it’s easy to overdose on it.

What is melatonin and how does it work?

Melatonin is a hormone secreted in the body by the pineal gland. These hormones control your sleep-wake cycles (circadian rhythms) and are generally at high levels during the night. These levels start to fall as the sun rises thereby causing you to awaken.

Melatonin can also be synthetically made in the labs and used as a medicine to adjust the body’s sleep-wake cycle. This supplement is commonly available in pill form and it’s used by people suffering from insomnia (inability to fall asleep), delayed sleep phase syndrome, and sleep problems caused by traumatic brain injury.

This supplement is also used when traveling to combat jet lag and it’s also used as a ‘sleeping pill’ by people who work at night.

How much melatonin should I take?

There are variations on what is considered as the right dosage of melatonin. This is because there are a lot of factors that come into play including your age, weight, health status, and why you are taking the supplement.

All in all, the commonly recommended dosage for the average adult is between 0.2g and 20g although high doses of up to 40mg have been prescribed when dealing with serious health issues. Here are WebMD’s recommended doses of this supplement.


  • Primary insomnia (trouble falling asleep- 0.3mg – 5mg
  • Secondary insomnia- 2-12mg
  • Sleep-awake cycle disturbances- 2-12mg
  • Sleep problems in blind people- 0.5mg to 5mg
  • Insomnia emanating from beta-blocker drugs- 2.5mg
  • High blood pressure- 2-3 mg
  • For endometriosis- 10mg
  • For combating jet lag- 0.5 to 8mg after arrival at the destination and before bedtime. Taken for 2-5 days
  • Dealing with anxiety before surgery- 3-10mg


  • Primary insomnia (trouble falling asleep- 0.05-0.15 per kg of body weight
  • Secondary insomnia- 6-9mg
  • Sleep-awake cycle disturbances- 0.5-12mg
  • Sleep problems in blind people- 0.5mg to 4mg
  • Dealing with anxiety before surgery- 0.05-0.5mg

Can you overdose on melatonin?

Well, melatonin has not been found to cause death. However, taking too much of it has been found to lead to a range of complications with mild to serious effects. Most of these complications may be an issue, for instance, when driving or operating heavy machinery.

The most common effect is disrupted sleep since too much melatonin in your system affects your normal circadian rhythms.

You’ll tell that you’ve overdosed on melatonin if you feel groggy and excessively sleepy during the day. Too much of this supplement may also cause nightmares at night.

Here are other side effects of excessive consumption of this supplement;

  • Joint pain
  • Diarrhea
  • Dizziness
  • Headaches
  • Nausea
  • Irritability/anxiety

Safety Tips when Taking Melatonin

  • While this supplement is effective in giving a shuteye, keep in mind that it should not be used by anyone.
  • Although the risk of developing serious health complication due to its use is very low, always consult a sleep specialist or pharmacist first more so if you are under other medications
  • As a rule of thumb, always start with the lowest dosage possible and work your way up until you get to the amount that works for you
  • Don’t take melatonin with alcohol or caffeine