Melatonin: Mechanism to Action, Effects, Dosages, Side effects

Product Overview
Melatonin: Mechanism to Action, Effects, Dosages, Side effects
Other Names:
MEL, Circadin, Melatol, MLT
Active ingredient:
N-acetyl-5-methoxy tryptamine
Dosages (mg):
1/ 3/ 5
Drug Class:
Miscellaneous Anxiolytics, Sedatives and Hypnotics
Sleep Disorders

The human body is making melatonin on a regular basis. Melatonin is one of the most important hormones produced in our organisms. Melatonin is responsible for controlling our sleep and wake cycle.

Melatonin is produced in the pineal gland in the brain. This pea-sized part of the brain is located right behind our eyes. Because pineal gland is situated right behind our eyes, it receives the information about the amount of light coming through the lenses of our eyes. For that reason the pineal gland is sometimes referred as a “third eye.” If there is light around, there is an interference with the signal that our brain is sending to our cells in order to repair them. Since there is so much interference, the brain would not send these signals, as the cells would not hear the signal anyway. The brain waits until it’s dark to send these signals.

The studies have shown that the brain can’t distinguish between the electrical light and the natural daytime light, which the sun gives.

During the day time, the pineal gland is working hard in making melatonin for storing it for further usage. Under low light levels conditions, the pineal gland starts to release melatonin, this way creating a sleepy feeling, which eventually makes us fall asleep. While we are sleeping, the pineal gland is still releasing melatonin, until there is the time for us to wake up. Then, at the end of the sleep-wake cycle, the pineal gland gets back to produce melatonin once again. So the cycle continues.

How does melatonin work?

Melatonin is the bodies wonder natural drug.

Melatonin is a very powerful antioxidant. For example, melatonin is five times as powerful as Vitamin C and twice as powerful as Vitamin E. Each day our body leaves around half a billion cells. At night, these cells are replaced through the process of dividing the cells. Melatonin is moping out free radicals, which are the leftover product of making the energy, which we need to repair our cells in the first place. As our body repairs itself each night, millions of these free radicals are created. They attack healthy cells, and are the cause of many deceases, including cancer. This is where melatonin comes to help healthy cells in the battle with free radicals. Melatonin is a very powerful hormone and an anticancer agent.

Melatonin also makes your skin look younger.

Frequently Asked Questions

What is melatonin?

Melatonin is a natural hormone that comes from pineal gland. It is responsible for initiating sleep cycles. It is not so much that it puts you to sleep. Melatonin has a major role in helping you go through all stages of sleep, which is very important to heal and restore your body.

What function melatonin has?

Melatonin also calms down a brain’s neuroactivity, relaxes muscles, slows digestion. A good way to think about melatonin, is to compare it cortisol, which is a stress hormone with high levels of it in the daytime. Melatonin is the opposite; it is lower in the daytime. But as you get towards nighttime, cortisol is dropping and melatonin is coming up. These two hormones sort of counterbalance each other.

Most of these effects are traditional effects of melatonin, They happen with melatonin anywhere between .5 and 3 mg at night.

Melatonin can be very powerful for some people. If you have never taken it before, please, do not start with 3 mg a dosage. There is a famous saying used in medicine, “Start low and go slow.” Whether you are dealing with a prescription drug, exercise or melatonin supplements, start slowly, with a lower dosage, and see what happens.

What are the benefits of melatonin for the human body?

Except being a sleep regulator, melatonin has a number of functions, all of which are beneficial to our health and overall well-being.

First, melatonin is good for your bone loss. Animal studies have shown, that melatonin helps preventing bone loss. This is crucial for the older generation, who can experience bone loss, caused by a variety of conditions, such as osteopenia. Older animals’ studies have shown that indeed melatonin helps with bones. The animals were divided into two randomly assigned groups. The first was treated for 10 weeks with melatonin, and the second group was not treated with an anything. What they found is that animals treated with melatonin had a higher bone volume, they had more middle part of a bone, and thicker edges of the bone in comparison to control group.

This is exactly what is happening with the human body as well, as animals make a traditionally very good model for studying effects on the human bodies.

Another effect of melatonin is the increased bone flexibility. Bone strength is not really connected with how much calcium and, mineralization is in the bone, these can actually make the bone weaker. Bone strength is measured by flexibility. Especially long bones, for example, bone in your arms and in your legs. That flexibility does not come from minerals, it comes from the special protein. Melatonin has an effect on bone flexibility and therefore, bone strength. These compelling results were indicative of that dietary supplementary melatonin is able to exert beneficial improving of microstructure and biochemical improvement of aged bones.

What if someone has a reduced amount of melatonin?

If you have a reduced amount of melatonin, your immune system starts to be less competent. You also will probably have a sleep disturbance. You can’t get off the sleep easily. And if you do, you can’ get back to sleep easily. Also, because melatonin protects your heart as well, if the levels of melatonin are insufficient, you can also have certain heart complications.

Since your immune system is not functioning to make its best, you are much more prone to a variety of deceases.

Just to provide you a very striking example, the average woman with breast cancer, has only one tenth of the normal level of melatonin.

Another example: people with prostate cancer have less than half of the level of melatonin than they should have had.

Also, children with autism also have reduced levels of melatonin. It is on average half as much as they should have in their age.

If an individual is working nights, his or her level melatonin are also get reduced with time, which makes him or her more prone to have cancer.

People who are blind have also different cancer rate than the average population.

How long melatonin lasts?

Time release of melatonin is around 3 to 4 hours. If you are planning to move your sleep schedule for more than three hours, you may want to take another pill in three hours.

Can melatonin prevent headaches?

As a matter of fact, it can. Recent studies have shown that melatonin is good for migraine sufferers. Taking melatonin supplements 30 minutes before bedtime can help curb migraine headaches. This is according to the small study conducted by Brazilian scientists. During the first months of the studies, the participants did not take any melatonin, while the observants were looking into the migraine pattern in the participants. During the studies last three months, the participants took 3mg of melatonin 30 minutes before the bedtime. They found at these studies that two thirds of participants said that the migraines were reduced, by half or even better. Some said that the migraines were gone at all. Overall headache intensity was also reduced at the beginning of the study. The women’s average migraine level was 7 in the scale 0 to 10. And that dropped to 3 on the same scale by the end of the study.

3mg of melatonin 30 minutes before your bedtime might be something you want to discuss with your physician if you suffer from migraines.

What is liquid melatonin?

Melatonin in a liquid form is a very effective pill that works a bit faster than a regular melatonin pill.

The inner capsule is with melatonin timed-release beadlets. It is in a liquid melatonin−filled outer capsule. It releases a hormone immediately, which gives a quick sleep response. On the other hand, the inner capsule, where melatonin packed in different sizes, dissolves at intervals to promote a balanced sleep.

What is the optimal dosage of melatonin supplements?

It is generally better to start with half of milligram, and then gradually increase the dosage up to 3 mg. However, the dosages should be adjusted according to your individual response.

What are the side effects of taking melatonin supplements?

The most common complaint is when an individual is waking up the next day, and complain feeling groggy and/or seeing weird, disturbing dreams. It is not a reaction however; this is just a normal response for people. These effects mean that the dosage was too high for you. Just lower the dosage slightly and you will be ok.

Why it is necessary to take melatonin?

Melatonin production levels can be different from person to person. There are many factors that can affect the production of melatonin. These include age, lifestyle, exposure to light, working conditions, overall environment, oxygen levels outside, diet, and many more. If you find yourself suffering from occasional sleeplessness, that is a good sign that your body is not producing the amount of melatonin it actually needs. Taking supplemental melatonin can help filling this gap.

What studies on melatonin show?

There have been more studies on melatonin than even on paracetamol.

Over the years, scientists have conducted numerous studies on melatonin and its impact on the human organism. The majority of these studies demonstrate the effectiveness of melatonin while combatting the occasional sleeplessness.

One of these studies was conducted in the University of Glasgow in 2007. The study was examining the effect of melatonin on 523 adults. The study was what is known in science as “double-blind.” One group of patients took placebo, and another group of patients took melatonin. As a result of these studies, the scientists found out that taking melatonin results in significant and clinically meaningful improvements in sleep quality. Melatonin improved morning alertness, sleep onset latency, and what is more important, the overall quality of life.

How much melatonin is too much? Can I have an od of melatonin?

There is no definitive dose of melatonin that would be considered an overdose. Melatonin affects people differently. Some take just little and experience some side effects; others can take hundreds of milligrams and have no adverse effects whatsoever.

Melatonin doesn’t have a suggested dosage like some other drugs have.

It is really an individual drug to take. We recommend you to start with lower dosages and see how it goes. Then you can gradually increase your dosage, if necessary. If your bottle of melatonin has directions of taking 3mg to 5 mg, we recommend you to start with 3mg.

Melatonin vs sleeping pills. What to take?

Melatonin has proved to work better as a sleeping aid than the regular popular sleeping pills, such as Ambien and Lunesta. Melatonin has very little side effects compared to sleeping pills and is cheaper. Being a natural hormone, melatonin is more predictable as far as interaction with the processes inside the human body.

Can I take melatonin and alcohol together?

It is not recommended to take melatonin with any amount of alcohol. As both melatonin and alcohol work as sedatives, their effects might interfere. Drowsiness and hallucinations are possible.

When should I take Melatonin?

Melatonin is recommended to be taken 1 to 2 hours before planned bedtime.

Is melatonin good for dogs?

What is melatonin?

Melatonin is a hormone produced in the pineal gland of mammals. It occurs in humans as well as in dogs. Melatonin is responsible largely for regulating phases of sleep. As such, melatonin is crucial in preserving a healthy state of the body of an animal and for overall well-being.

How could melatonin be used in dogs?

There are many positive effects that melatonin brings. While it is a perfect sleeping aid, it also has numerous other applications. These include separated anxiety treatment, treatment of hair loss in dogs, also known as canine alopecia, and also treatment of several forms of phobias.

Other treatments melatonin is used for include aid in gaining weight, which was a result of bad nourishment associated with ailments as well as surgeries.

Common uses of melatonin for dogs

Melatonin can be used to treat the following conditions and ailments in dogs:

  • Alopecia X
  • Insomnia and complications with sleep
  • A variety of phobias
  • Anxiety disorders
  • Thrombocytopenia

Insomnia in dogs can be a symptom rather than a disorder. It can be an effect of emotional distress of your pet or physical pain (like, pain caused by arthritis.) Same goes for anxiety and phobias.

It is strongly recommended that you first establish the cause of the condition, and only then start applying the melatonin treatment.

Consider the following possible causes of psychological and sleep disorders in dogs:

  • New neighbors
  • Overall level of the emotional tension in your household
  • Age of a dog. The age factor is crucial, and it varies depending on a breed. Age can be an underlying cause of such ailments as joints complications.

Consider applying the medications specifically designed to treat this type of ailments.

If you will manage to relieve your dog’s pain, she will be having a healthier sleep and also will be enjoying a healthier lifestyle.

Is melatonin a natural substance?

Melatonin is a natural hormone, and giving to your pet while is completely safe if you follow the directions.

Melatonin for dogs vs alternatives

As a natural substance, melatonin has an advantage over synthetic medicines designed for anxiety and sleep disorders treatment in dogs.

However, there are plenty of alternatives for melatonin.

If your dog is experiencing anxiety, and you see she is agitating, you can try to give her tranquilizers. However, there are many side effects observed upon giving tranquilizers to a dog. Exactly like with humans, too much tranquilizers can give a dog a depression condition, and at times even hallucinations.

Conditions and Melatonin Dosages

Normally, vet doctors recommend following dosages of melatonin depending on the condition

Condition Suggested approximate dosage
Hair loss. This condition is also called Alopecia-X, pseudo-Cushing’s, atypical Cushing’s, congenital adrenal hyperplasia-like syndrome and CRFA
  1. One 8 mg – 18 mg injected implant. Usually the frequency of administering this implant is once in 3-4 months. The frequency should be established by your vet.
  2. If treating orally, the recommended dosage is 3 – 6 mg every 8 to 12 hours
Sleeping conditions, such as insomnia Around 6 mg, administered by mouth. Frequency- every 12 hours. These can be given each 24 hours. Consult your vet for exact dosage your dog needs.
Anxiety conditions, such as phobias Around 6 mg, administered by mouth. Frequency- every 12 hours. Can be given each 24 hours. Consult your vet for exact dosage your dog needs.


What is the right way to administer an injection to your dog?

Subcutaneous administering of melatonin for your dog can be done at home, but you should follow the directions.

  1. Take a syringe and uncup the needle.
  2. Insert the needle into the vial.
  3. Pull back to get as much as you need. You want to make sure there are no air bubbles in the syringe. If you see any air bubbles, tap the syringe just a little and push back just enough to get these air bubbles out of the syringe.
  4. Pull out and recap your needle. Then change the needle with another one.
  5. Find where the shoulder blades in your dog are, and administer the needle right under the skin.
  6. Lift up the skin lightly and insert the needle. Pull back to make sure there is no blood.
  7. Administer the shot.
  8. Pull out the needle.
  9. Place your finger on the spot you administered your shot on. This is to make sure there is no leaking on the spot.
  10. Recap your needle.

Important: At all times make sure to sterilize the spot on the body of the dog you are giving the injection to and to change the needles after use to avoid possible infection.

How Safe Is Melatonin for a Dog?

Generally, melatonin is a safe drug with little or no side effects.

Many veterinary professionals have successfully and ultimately safely used melatonin implants to treat hair loss in dogs while observing no harmful effects or reactions. Remember, each melatonin implant can last as long as 4 months at a time.

It is generally not advised to give melatonin to pregnant dogs and puppies (when the age is under 3 months.)

If you still consider giving melatonin to your dog in the above condition, make sure to consult your veterinary professional.

General safety guidelines in using melatonin for a dog

If possible, consult a vet doctor, who you can find in the nearby vet clinic. Tell the doctor all medical history of your dog, including all the ailments the dog has been suffering and all the medications you are giving to your dog at the moment.

If you are considering giving your dog subcutaneous implants, please follow the guidelines of proper injection. Also make sure to avoid accidentally injecting melatonin into the muscle or into the bloodstream.

Most veterinary professionals can give a proper injection and it is best to delegate this task to them.
If your dog has hair loss it’s highly recommended that you seek a diagnosis, as hair loss is also a symptom and can be caused by a variety of conditions aside from Alopecia-X.

These include:

– thyroid disease;

– parasite infections;

– bacterial infections.

Needless to say, these conditions will lead to the totally different course of action to treat them properly.

Counter indications for using melatonin in dogs

As with humans, it is highly recommended to avoid using melatonin for your dog, if it has any of the following:

  • problems with liver;
  • conditions that affect the brain of the dog;
  • bleeding disorders;
  • any types of seizures;
  • poor kidneys.

Consult your veterinary professional if any of the above is present.

Melatonin is slowing clotting processes in the blood flow of a dog and it is not recommended to administer it in combination with medications with anticoagulant properties such as aspirin.

You may also consider using diphenhydramine formulation of Benadryl if insomnia relief is needed. Be aware that Benadryl is not a natural substance.

Side effects of using melatonin in dogs

Side effects of using melanin in dogs are rarely observed, but we include this list in case you worry about them.

If melatonin was given to a dog orally following side effects may occur:

  • Sleepiness;
  • Changes in fertility;
  • Elevated heart rate;
  • Itching;
  • Upset stomach;
  • Mild headaches;

If melatonin was administered via implants, the following side effects may take place:

  • Sterile abscess around the place on the skin of a dog where the drug was injected;
  • Itching around the place on the skin of a dog where the drug was injected.

These are caused by the remaining drug around the skin area, and it is natural that irritation is caused. However, these side effects are quick passing. You may want to consult your veterinary specialist for the best way to get rid of mild side effects.

Overdose of melatonin

In case you will notice an overdose upon administering your dog a melatonin, please contact your vet immediately.

Usually overdoses are very mild, and result in upset stomach and higher sleepiness.

If your dog is specifically susceptible to melatonin, she may experience high blood pressure or seizures. Make sure to consult your veterinary doctor before administering melatonin for the first time.

Melatonin for animals is still the subject of ongoing research, and it is best to start with lower dosages.

Online Guide on Melatonin for Kids

The use of melatonin in children

If your kid is experiencing unusual sleepiness, may be right after his or her school or kindergarten is over, or if your kid is having irregular bedtime pattern, you may want to consider using melatonin. It is a natural, safe, and effective medication.

Melatonin is used in children with chronic insomnia. Melatonin also can help the management of sleep if disturbances are present caused by attention deficit/hyperactivity disorder or neurologic injuries.

What is melatonin?

Melatonin is a hormone that is naturally produced in the human brain on a constant basis. The primal function of melatonin is to regulate a sleep cycle. Melatonin’s production going on during the sleep state, while during the doing time its production is suspended. The pineal gland, where melatonin is produced, starts to release melatonin when there is darkness around. That is why it is preferable to follow the sun in your sleep cycle.

Melatonin is also responsible for a variety of functions inside the human body. It helps coping with dangerous cells; it improves the flexibility of bones, and many more.

Where I can purchase melatonin for children?

Melatonin is available in any drugstore. You can also buy melatonin in online pharmacies. Make sure the online pharmacy is providing melatonin from reputable sources.

How can melatonin improve my child’s sleep?

The studies conducted on melatonin, have clearly shown that the use of melatonin can make a time of falling asleep for children shorter. The group of children who is suffering from attention deficit/ hyperactivity disorder, Asperger’s syndrome and other forms of autism was tested, and the results have shown a positive shift in time it takes to fall asleep.

However, when studies on how melatonin helps children to stay asleep were conducted, the results were not that optimistic as in the former study.

There is a variety of reasons children may have hard time in falling asleep. These include anxiety, restless legs, and early bedtime. Please consult your pediatrician for the exact cause of the condition. Normally, a careful evaluation of all the factors required before melatonin is being prescribed.

There is a variety of behavioral practices that may help result in a healthier sleep for a child. For example, consider taking measures of not using smartphones and other electronic, light-emitting gadgets that almost always suppress the natural emission of melatonin in children.

What are the side effects of Melatonin when used in children?

Melatonin is well-tolerated. Most clinical tests conducted in use of melatonin in children turned out no adverse effects.

Rarely observed melatonin side-effects include:

  • Mild headache
  • Increased bedwetting
  • Feeling groggy in the morning
  • Excessive sedation
  • Transient depression

All of these are observed if the doses were greater than 8mg a day.

In some cases following side effects were observed:

  • Rash
  • Psychotic episodes
  • Gynecomastia
  • Autoimmune hepatitis

However, in those cases melatonin was used, but was not identified as a direct cause of side effects.

In cases of children with seizures, melatonin is to be used with extreme caution. Some studies have shown that melatonin may cause worsening of seizures.

Melatonin plays a role in human immune function. For this reason melatonin is not recommended for children with autoimmune disorders.

Is the use of melatonin in children safe?

Parents should become aware, that the studies on melatonin and its side effects are not conclusive to the date. Some studies on melatonin in animals have shown, for example, melatonin’s connection to puberty-related hormones. There is very little evidence that the connection is the same with humans, but no sufficient studies sufficient for establishing the exact relation of melatonin and puberty-related hormones were conducted.

It is also highly recommended for the parents to make sure that melatonin they are purchasing for children is guided with the description of the exact dosage each pill contains.

When melatonin for babies is not to be used?

As we described earlier, complications with sleep in children may occur for many reasons.

Please avoid giving children melatonin in one of the following scenarios:

  • If the episodes of insomnia are occasional. For example, insomnia in children is frequent when there is anxiety connected to a new year in school or kinder garden.
  • If the insomnia is present, but is relatively short-term. For example, the insomnia may be caused by infections.
  • If the insomnia happens because of the result of a physical cause. For example, it may be caused by sleep apnea.
  • Avoid using melatonin if your children are of the age under 3 years.

While melatonin is an excellent natural sleep aid, it can never be a substitute for overall healthy sleep practices, such as regular bedtime routines that fit for the particular age, avoiding taking caffeine-contained drinks and food, and avoiding the excessive use of light-emitting devices, like smartphones and laptops.

What is the optimal dosage of melatonin for toddlers?

The available studies on the use of melatonin in children suggest the initial dose of melatonin from 2,5 to 5 mg.

This dose is best given in the evening time, around 1 hour before the anticipated bedtime.

The titration of the dose should be corrected depending on response.

If children experience nighttime awakenings, a controlled release dosage is recommended.

What is the price on melatonin for children?

The cost of a bottle that contains 3 mg tablets of melatonin varies from $3 to $8.

Melatonin can be obtained at most pharmacies. Melatonin is also sold at big chain stores such as Walmart. Melatonin is produced as immediate release as well as controlled release pills.

The current available dosages on the market are 300 mcg, 1mg, 3mg, and 5 mg.

Is melatonin for children available everywhere?

FDA does not put any constraints on melatonin, as it is not a drug product.

It is recommended to buy synthetic melatonin as opposed to bovine-derived melatonin, because the latter may bring infections.

Conclusion on the use of melatonin for kids

It is recommended to use melatonin in children only after an approval of a doctor. Melatonin is the efficient means to cope with difficulties in falling asleep. Melatonin is most effective when combined with a set of behavioral and healthy sleep practices.

What are the common Melatonin side effects?

There are almost no adverse effects associated with melatonin.

Known mild side effects include following:

  • Drowsiness. If you took melatonin at the wrong time, you will feel groggy after you’ve slept. It is easily corrected by adjusting your sleep schedule.
  • Hormonal changes. Because melatonin is the actual hormone, it is not recommended to be taken for pregnant women. Melatonin can also interfere with ovulation and sperm-production, in women and in men, respectively.  If you are planning to conceive a baby, avoid melatonin for a while. If you have any hormonal complications, consult your doctor.
  • Changes in mood. These are sometimes observed; you can experience feelings of being sad and lost.
  • Hallucinations and vivid dreams.  Depending on an individual, one may experience unusually intense and colorful dreams. In some cases, hallucinations are present. We recommend you reducing the dosage if these effects are troublesome for you.
  • Seizures episodes. It is generally not recommended to take melatonin if you have seizures in your medical history.
  • Upset stomach. Mild nausea and upset stomach are common side effects of melatonin. These are quick passing, though.

And finally, please avoid taking melatonin if you are a breast-feeding mother. There is not enough scientific data on how exactly melatonin interacts with other hormones.

Melatonin: Interaction with other drugs

It is recommended to consult your doctor if you are planning to take melatonin with any of the following drugs:

  • Drugs affecting blood pressure;
  • Blood thinners;
  • Drugs for preventing seizures;
  • Drugs targeting the functioning of immune system;
  • Anti-depressants and sedatives;
  • Any caffeine or alcohol contained medications;
  • Sleeping pills;
  • Pills for diabetes;
  • Fluvoxamine (Luvox), which decreases melatonin absorption in your body;
  • Medications for slowing blood clotting.

Important: Consult your medical specialists if you are prescribed with any of the above types of medicine, or planning to take them together with melatonin. For a complete list of melatonin interactions, please consult your nearest health provider.