How Long Melatonin Stays In Your Body –Dosage and Efficacy

Melatonin is a hormone that is produced by the body when your eyes are exposed to darkness. And as pineal glands begin releasing melatonin into your blood stream, you start to feel calm and relaxed. Today, melatonin is available around the world as an over the counter sleeping aid.

Many people looking to consume this medication usually wonder about how long it takes for melatonin to work. This is a genuine concern because you need to time the consumption of melatonin and your desired time to sleep. On average, melatonin takes about 30 minutes to one hour to take effect. That is why it is safe to say that you should take the medication about 30 minutes before heading to bed.  

You can easily find over the counter melatonin tablets at any drug store near you. After taking it, it can last in your system for a period of 5 hours. People who can use melatonin to regulate their circadian system include:

  • Travelers who experience jet lag
  • Workers who operate on night shift
  • People suffering from dementia
  • People who are blind
  • When you are taking medications that hinder sleep
  • Children with chronic conditions such as autism

Although melatonin is designed for sleeping disorders, it can also be helpful in patients suffering from other conditions such as migraines, attention deficit disorder and irritable bowel syndrome. Below, we will look at how long it takes for melatonin to work, how it works as well as the best time to take this medication.  

How melatonin work

Melatonin is secreted by the pineal glands that are located at the middle of the brain.  This gland is controlled by a group of neuron that is located in the hypothalamus. The neurons control your body timer by sending signals to one another. During the day, light gets into your retina and send a signal to the suprachiasmatic nucleus. This forces the pineal gland to stop producing melatonin. As a result, you are able to remain awake for a long time.

During the night, the eyes send a signal to the pineal glands to start producing melatonin. This forces the body to shut down causing you to sleep. As melatonin level in the blood increase, your blood pressure and temperature falls, prompting you to fall asleep.

How long does it take for melatonin to work

Melatonin is readily absorbed by the body. As soon as you take the supplement, your body starts absorbing it and takes effect within one hour. It is at this point that you might start to feel sleepy. However, there are some factors that affect how long melatonin takes effect.

‘Factors such as one’s body, dosage and release rate may affect how fast melatonin takes effect on your body’ says Dr. Arnold.

Immediate-release vs. extended-release melatonin

The most common melatonin tablets are immediate release types that readily dissolve as soon as you take them. This readily releases the hormone into your blood stream causing you to fall asleep soon.

On the other hand, there is extended-release melatonin that slowly releases melatonin into the bloodstream. This takes time to discharge melatonin into the blood resembling the way the body produces melatonin over the night. This is important for keeping you asleep over the night.  Depending on your sleeping problem, a doctor may decide on the type of melatonin release that is suitable for you.  

Melatonin dosage

Normally, melatonin comes with a dosage of between 1 and 5 mg. however, it is important to start with the minimum dosage before proceeding to a higher dosage. This is dependent on your response to the medication. You can adjust the dosage based on your response to the medication. If you find that the dosage is not enough, you can adjust your intake to suit your needs.  The right melatonin dosage should make you sleep without causing any adverse effects.  

Unfortunately, taking a lot of melatonin can have adverse effects on your health. This is because; an overdose disrupts the circadian rhythm causing you to sleep during day time.

In the medical field, melatonin is considered as an over the counter medicine and is available at major drug stores around the globe. The supplement is ranked amongst other dietary supplements such as vitamins and minerals. And without regulation, most manufacturers put their own dosage on their products. Therefore, it is advisable to talk to your doctor before consuming melatonin.  

When should you take melatonin?

It is recommended to take melatonin 30 to 60 minutes before going to sleep. This is because melatonin takes about 30 minutes to take effect in the body. However, it is important to realize that every person responds to melatonin differently.


As we have seen above, melatonin takes half an hour to take effect.  On the other hand, it lasts 5 hours in the body. Therefore since our bodies respond differently to melatonin, you should find a dosage that works well with your body.