How Much Melatonin Is Too Much? – Can It Actually Kill You?

is melatonin safe

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Have you found in melatonin the perfect solution for your sleeping problems? As you may probably know, this magical chemical basically tells your body that you need to sleep once it gets dark. This amazing pill really gives you the possibility to sleep like a baby if you suffer from insomnia or if you simply are one of those who tosses and turns in bed for hours with your mind running fast, not letting you sleep at all.

But, can too much melatonin kill you? Have you taken more than the normal recommended dose and are you worried about something happening to you?

Stay with us for a few minutes, and here we will explain to you which are the possible consequences of taking too much melatonin, its side effects and why there is still some debate out there about what the recommended dose is.

Is Taking Melatonin Safe?

The common understanding among melatonin consumers is that it is a perfectly safe sleep aid which tackles a lot of health conditions. Even though this is partially true, there are some risks that come with taking it that need to be taken into account.

This chemical is mostly considered to be safe because it’s actually a hormone that the body produces naturally in every human being. But taking melatonin pills because you think you need it for being able to sleep or because your body does not produce enough of it naturally, has to be taken seriously, as with any other medication.

Taking more melatonin than the recommended dose is not known to cause death, but it can bring a lot of undesirable side effects with it. Later in this article, we will tell you all about these side effects in detail.

How does it Work?

The human body is without a doubt one of the most exceptional things. The way it works with certain things is nothing short of impressive. Regarding melatonin, our body starts producing it and increasing its level once it starts getting dark. As it gets darker, more and more of this hormone keep being produced, telling us basically that it’s time to sleep.

People whose bodies don’t produce enough of it have sleeping problems such as insomnia. Basically, their internal clock is messed up, because their bodies are not receiving the alarm telling them that it’s time to sleep. Melatonin supplements can help some people achieve a better night sleep so they wake up feeling refreshed.

taking a melatonin pill

How Much Melatonin Can I Take?

The perfect dose of melatonin is considered to be that which will effectively help you to fall asleep at night, but at the same time without producing all the unpleasant side effects. A dose of between 0.2 mg and 0.5 mg would be perfect to start with, even though the perfect dose for you depends on your age, body weight, and your sensitivity to the supplement.

Another factor that needs to be taken into account is your sleeping circumstances. For example, for combating jet lag, the recommended dose for adults would be between 0.1 mg and 5 mg, while for insomnia in older people, a dose of between 0.1 mg and 5 mg should be enough.

Expert Recommendations

While checking at some scientific resources such as Mayo Clinic, we find that, as previously supposed, the right amount of melatonin depends on certain factors like age and sleeping circumstances.

10mg Dosage

Generally speaking, this is considered a mild dosage and should be safe.

20mg Dosage

Melatonin at 20 mg is considered a high dose and should only be used for serious sleep concerns.

30mg Dosage

This is a high dose and often used to treat clot-forming cells.

100mg Dosage

This is an extremely high dosage and should not be used. It is very dangerous.

What to do in case of an Overdose

It’s not easy to define what a melatonin overdose is because as we can see, the recommended doses are not entirely clear and vary considerably according to a lot of different factors.

However, if you feel unwell and have many of the side effects that we will get into detail below, then you have probably taken a bit too much of it and need to call your doctor immediately.

You can also call the Poison Help Line at 1-800-222-1222. Or if you have serious symptoms like sudden chest pain, shortness of breath, or a 180/120 or higher blood pressure, then please call 911 because your condition may be really urgent, even though these symptoms are probably not related to melatonin itself, or even a combination of the pill and other medication.

man taking an emergency call

Common Melatonin Side Effects

Even though it’s mostly safe, it can bring a lot of different unpleasant side effects when taken in large amounts and/or during an extended period of time of more than 2 years approximately.

First, taking too much can actually end up having the opposite effect of its intended purpose. A dose larger than what’s recommended can disrupt your normal circadian rhythm and make it harder, or almost impossible for you to sleep.

Among other most common side effects of melatonin are the following: extreme sleepiness during the day, a decrease in body temperature, dizziness, nausea, terrible headaches, anxiety or irritability, joint pain, diarrhea, blood pressure changes, grogginess in the morning, and awful nightmares or extremely vivid dreams during the night.

There are certain conditions that, if you already suffer from them, can get worse by high usage of melatonin. Among these conditions are:

  • Bleeding disorders: it might make bleeding worse if you have any kind of bleeding disorder.
  • Diabetes: it can increase blood sugar for you if you suffer from diabetes. If you take it and have diabetes, monitor your blood sugar carefully.
  • Depression: it can make a lot of your depression symptoms worse.
  • High blood pressure: it can raise your blood pressure even more if you are taking specific medication to control blood pressure. If this is the case, simply avoid using it.
  • Transplant recipients: by increasing immune function, melatonin may interfere with immunosuppressive therapies applied to people who are receiving transplants.
  • Seizure disorders: it may increase your chances of having a seizure if you already are prone to it.

Some special precautions and warnings must be considered for children or pregnancy and breastfeeding:

  • For children, melatonin is possibly unsafe when taken either by mouth or injected into the body in multiple doses in the short term. It might also interfere with development during adolescence due to its effects on other hormones produced by the body.
  • For pregnancy and breastfeeding, melatonin is possibly unsafe when taken either by the mouth or injected into the body, and its use during these periods for women is extremely discouraged. It can also interfere with ovulation, negatively affecting the chances of getting pregnant.

Below we will review and detail some of the most common side effects of melatonin that apply to everyone. Please read carefully and consider all these things before taking the supplement.

Mood Changes

A wide range of mood changes may occur if you take large amounts of melatonin. Sadness, overexcitation, or depression are not rare, and if you’re feeling these things after using it, you should not be surprised.

If you already suffer from any kind of depression condition, then you should avoid using melatonin unless it has been expressly recommended by a doctor.

Grogginess in the morning

Grogginess is probably the most common side effect of melatonin. If you take the supplement at the wrong time, you are very likely to end up being groggy the next day. This is particularly important if your day-time job requires driving or operating heavy machinery because it obviously can lead to terrible accidents.

Nausea and Diarrhea

This is, after grogginess, nausea is the second most common side effect. It may occur even without amounts larger than the recommended. Very low doses may also make you go through vomiting, nausea, stomach pains or diarrhea.

Disorientation and Paranoia

The risk of disorientation or paranoia only exists when taking large amounts of melatonin, way above recommended doses, but it can happen. You may experience strange hallucinations, complete disorientation, delusions, paranoia or general confusion.

Hormonal Changes

There is always a risk of hormonal consequences when taking a synthetic hormone. At some times, this can be serious. It can reduce the libido both for women and men, and also interfere with men’s sperm count or with women’s ovulation.

As we’ve said before, taking melatonin should be completely avoided for pregnant women, as it may have negative effects on fetus growth.

Vivid Dreams

People take this pill for being able to sleep, but sometimes they can end up having very unpleasant dreams, probably worse than not sleeping at all.

Large amounts of melatonin may cause people to have extremely vivid dreams, or increase the frequency and intensity of other sleep disorders like nightmares or sleepwalking.

woman sleeping in bed

Avoid with the Following Drugs

As is the case with most medications, melatonin can interact with other drugs and cause unpleasant consequences. So, if you are about to take it and are already taking or are planning to take any of the following drugs, please consult a doctor first!

  • Drugs affecting your immune system.
  • Drugs used to prevent seizures.
  • Blood pressure medicine.
  • Blood thinners, like Heparin or Warfarin.
  • Medication for diabetes.
  • Any drugs that may cause you to be drowsy, like sedatives, muscle relaxants, painkillers, some cough medicines, or any other kind of sleeping pills.
  • Anything that contains caffeine.
  • Alcohol or anything that contains alcohol.
  • Anti-psychotics or anti-anxiety drugs like Benzodiazepines.
  • Anti-coagulants or medication which slows blood clotting.
  • Drugs which can decrease the amount of melatonin that your body can absorb, increasing this way the risk of all side effects. For example, Luvox.


So, even though melatonin may be very helpful for some people that need something extra for being able to sleep, it’s not for everyone. The recommended doses vary a lot according to many factors, and some of them are hard to identify. You may have some trouble tolerating melatonin, even at low doses. Or maybe you have no problem at all, and it will simply help you sleep every night like a baby.

Can you overdose? The answer is yes if we understand as overdose to feel unwell and have a wide series of unpleasant side effects. But it is a mostly safe drug, and it is not known to cause death or nothing too serious.

We have given you a long list of possibly harmful side effects of melatonin, so you now know exactly what may happen to you if you take the supplement.

We would recommend the use of melatonin for people who are having a very hard time sleeping, after consulting a doctor in any case. And start with the smallest possible doses first, see what it does to you. The smallest dose may be enough for helping you sleep; and if it does not, it’s a good idea to increase the dose little by little, while also monitoring how you feel.

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