Melatonin Side Effects—How It Sabotages Your Sleep And Causes Sleep Disorders

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Melatonin is a hormone naturally produced by your pineal gland that is located just above the middle of the brain. The natural hormone is released to control the pattern of waking during the day when it is light, and sleeping in the night when it is dark. It is a natural part of human life.

Melatonin is sometimes called the “Dracula of Hormones” as it is only released when it gets dark. In bright lights, whether in sunlight or artificial indoor lighting, your body will not produce melatonin. That is why, it helps to prepare to sleep by turning down the lights about an hour before you go to bed. Melatonin is then produced that will help sleep come easier.


Who Uses Melatonin?

There are many factors that affect a person’s sleeping patterns, including stress, dietary, internal imbalanced body chemicals, lifestyle, hormonal factors and any sleep disorders.

People experiencing difficulties falling asleep, staying asleep, or insomnia, often seek out medical help and are prescribed melatonin pills instead of being counselled on their inability to fall asleep.

Most notably, melatonin is prescribed to help with:

  • Insomnia
  • ADHD
  • Rapid eye movement
  • Sleep disorder
  • Delayed sleep phase syndrome
  • Insomnia due to high blood pressure medication

Other common uses include helping reduce the side effects of some cancer treatments including nerve pain, weakness, and weight loss.

Melatonin Is Natural, Isn’t It?

Yes, melatonin is a natural hormone. It is natural when it is produced naturally in your body. But it is not natural when it is synthetically produced in a lab.

Previously, melatonin was extracted from animals’ pineal tissues but this brought the risk of contamination. Melatonin pills are now available as an over-the-counter drug in various countries all over the world. It is generally available in the form of a pill or other forms, in which it is placed under the tongue or in the cheek for direct absorption into the body.

Synthetic melatonin has a wide range of uses, and they can all be broken down simply into “adjusting the body’s internal clock.” It is used for helping to recover from jet lag, for adjusting sleep-wake cycles in people whose work schedule changes often and even in blind people to help establish a day-night cycle.

When melatonin was first introduced in the last two decades, it earned high demand as a pill that is considered “safe”. It was inexpensive, easily accessible and appeals to even people who would rather avoid prescribed pills. After all, it is “natural”, isn’t it? Many people began to pop melatonin pills without thinking twice. Parents are even handing it out to their kids, believing melatonin to be a harmless, naturally-produced hormone.

Using it as a sleep aid, users are told to take a dose just before bedtime, when natural melatonin levels are already on the rise. Melatonin pills can be addictive as it does provide deep sleep when combined with your natural melatonin. Therefore, it is easy to take too much and becoming dependent. Many side effects of melatonin are the result of overdose—even though you may be taking it according to the dosage on the bottle, it does not take into account your internal, natural melatonin levels.

Neuroscientist Dr Richard Wurtman, said this:

“With some hormones, if you take too much you can really put your body in danger. With melatonin, you’re not in danger, but you’re also not very comfortable. It won’t kill you, but it’ll make your life pretty miserable.”

“Melatonin supplements may work at first, but soon you’ll stop responding because you desensitize the brain. And as a consequence, not only won’t you respond to the stuff you take … you won’t respond to the stuff you make, so it can actually promote insomnia after a period of time.”

“When it’s night time and melatonin levels are high, taking melatonin supplements is like putting a drop of water into an empty bucket; when it’s daytime, it’s like putting a drop of water into a full bucket.”

Melatonin Side Effects

Ingestion of melatonin hasn’t been demonstrated to cause fatal conditions in any human or animal species this far, even in supraphysiological concentrations (higher than the body is normally used to). However, such high presence of the hormone in the body has been shown to cause desensitization of melatonin receptors.

Inappropriate timing of the drug, even in low concentration, has similar effects in the body. Administration of large doses of the drug could have adverse effects on the body.

The drug has currently been given praises as a “wonder drug” to cure all kinds of ailments from aging to sleeplessness, often without any clinical efficacy. Clinical trials have proven its effectiveness when it comes to chronobiotic and resynchronizing effects (it can help in some cases) but is not effective as a foolproof drug without flaws.

melatonin side effects

Some of the confirmed side effects of synthetic melatonin pills include:

  • nightmares
  • abdominal pains
  • hypotension
  • anxiety
  • sleep disorders

Modern analyses of the known pharmacological profile of the drug and some of its metabolites, which are consequently based on various scientific preclinical trials and studies have shown the drug has adverse effects on the following specific aspects of the body:

  • the central nervous system
  • the immune system
  • glucose metabolism
  • the cardiovascular system—including platelet aggregation
  • hormonal problems
  • kidney and liver problems
  • even cancer

Melatonin is not guaranteed to be safe for use on everyone and is especially advised against, for special groups of people including pregnant women and people who operate heavy machinery.

For purposes regarding long-term use, the safety of the drug somewhat quavers. It is reasonably safe if used appropriately and can remain so for a period of up to 2 years in some people.

However, such dosage can come with additional side effects such as:

  • headaches
  • short-term depression
  • dizziness
  • disruption of the sleep-wake cycle
  • induced hypothermia—a disruption of body temperature
  • irritability

Special Precautions And Warnings For Taking Melatonin

As with most prescription medication, there are precautions for using melatonin. Unless advised by a doctor, using the drug in these circumstances is not recommended:

Pregnancy And Breastfeeding

Melatonin is unsafe for use, regardless of whether it is taken orally or injected into the body during any stage of pregnancy and should not be used. For women intending to conceive, it is similarly recommended not to use as it interferes with the ovulation cycle, making it more difficult to get pregnant.

There are currently no studies that have been conducted regarding breastfeeding mothers and melatonin, but it is best to avoid it all the same.


Melatonin is not advisable for use by children under the age of 13. It can be taken in single doses orally, but not so much so when taken by mouth or otherwise injected in multiple doses in short-term use. Melatonin interacts with other hormones in the body and may, therefore, interfere with development during the adolescence phase.

Bleeding Disorders

Bleeding disorders include a variety of inherited diseases such as hemophilia, which are manifested in the body’s inability to clot blood properly.

Normally, platelets (a type of red blood cell) clump together to form a sort of plug on the part of the body where one gets injured using blood proteins referred to as clotting factors. Once the platelets are all together, they form a fibrin clot to prevent blood from flowing out.

However, people with bleeding disorders either have a short supply of clotting factors or malfunctioned platelets, leading to excessive bleeding. Long-term use of melatonin may interfere with the formation of the fibrin clot and make bleeding worse.


As mentioned before, melatonin may interfere with the production of various hormones inside the body, and in the process make symptoms of depression worse. People on depression medications should avoid using it.

Similarly, people who suffer the risk of seizures, e.g. epileptics, should avoid using melatonin because of higher chances of experiencing the same, or worsening the condition.

Diabetes And High Blood Pressure

For people on diabetes medications, melatonin might increase blood sugar levels and cause a dramatic spike in blood pressure for people suffering from high blood pressure. These two groups of people should avoid using it.

Transplant Recipients

Melatonin increases immune function is some people and continuous usage might lead to interference with immunosuppressive therapy used by people who receive implants.

So What Natural Alternatives Do You Have?

Natural Sleep Remedy Mixture

I have recommended this natural alternative to my clients and most have done an easy switch from melatonin pills with taking a natural mixture of raw honey and seasalt. You can get the natural sleep remedy recipe here.

Other Sleep Tricks You Can Try

Tried and true methods to getting better quality sleep, and waking up refreshed.

4 juice recipes to remedy common sleep disorders that keep yo up at night.

The sleep-sock trick to help you sleep faster and easier.

Make this Ayurvedic spiced milk to help relax your body for better and deeper sleep.

How to perform the 4-7-8 breathing technique that gets you to fall asleep almost instantly.



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About Sara Ding

Sara Ding is the founder of She is a certified Wellness Health Coach, Nutritional Consultant and a Detox Specialist. She helps busy men and women identify their health issues at the root cause, in order to eliminate the problems for optimum physical/mental health and wellbeing.


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