How Long Does Melatonin Last?

Melatonin is a natural, mostly safe, and effective way to treat sleep disorders. Find out how!

Melatonin supplements have been used for a very long time to improve sleep quality. If you have trouble sleeping soundly, melatonin pills will be your best bet at an affordable cost. But how do melatonin supplements work? How long does melatonin last? What are melatonin side effects? 

Let’s find out.

What is Melatonin and what does it do?

Melatonin is the only hormone secreted by the pineal gland, the pine-shaped gland seated deep in the brain’s center and historically dubbed as “the third eye,” “the seat of the soul,” or the “tranquilizing organ” [1]. 

Though the pineal gland is the main site for the secretion of melatonin, you might find it interesting to know that it can also be secreted in minute quantities in cells of the bone marrow, platelets, retina, iris, lacrimal gland, gastrointestinal tract, skin, etc. [2, 3]. 

Did you know?
Melatonin is nicknamed the “hormone of darkness” because it is released in response to darkness [1]

The rate of synthesis and secretion of melatonin is higher in the dark than it is during brighter conditions. It also varies according to the activities you carry out during the day. About 80% of melatonin is synthesized at night [2]

Popularly known for regulating the circadian and endocrine rhythms in the body, melatonin is ubiquitous, found in every biological entity from bacteria to humans, and has numerous functions in the human body, including but not limited to [4, 5, 6].

  • Anti-inflammation
  • Antioxidant activity
  • Oncostasis (halting the spread of cancer)

Melatonin is also thought to play a huge role in regenerative medicine in the future [5].

Did you know? 

Melatonin was previously known as “the Dracula hormone,” “nature’s sleeping pill,” “Princess Diana drug,” “miracle hormone,” “the elixir of life,” “universal panacea,” etc. 

It had much media frenzy and cult status a few decades back because of its unjustified therapeutic claims and frenzied usage by the general population [1].

How Does Melatonin Work?

The circadian clock controls the sleep-wake cycle and hormone release. Photosensitive cells in the retina send photoperiodic (day-night) cues via the nervous system to the master clock (the suprachiasmatic nucleus), which further transmits it to the pineal gland. The pineal gland then synthesizes and releases melatonin, distributing the time signal to the rest of the body [7]. 

Since melatonin is amphiphilic (has both water-soluble and fat-soluble properties), it is not stored in the pineal cells but is released into the cerebrospinal fluid and bloodstream as and when it is synthesized [8]. 

Melatonin, due to its amphiphilic nature, has also developed an alternate mechanism of action. 

It can directly cross the cells, organelles, and nuclear membrane and interact with other molecules without being mediated by cellular receptors. Like any other hormone, it can also act via receptor-mediated actions [4, 8].

Melatonin reduces the levels of dopamine, which is associated with wakefulness. It also binds to receptors in the brain, reducing nerve activity and helps you relax [9]. 

  • The immediate effects of melatonin are seen at night when melatonin is released into the cerebrospinal fluid and the bloodstream and depend on several factors like concentration of the hormone, the target organs, etc. [4].
  • The prospective actions of melatonin, though primed during nighttime, are only expressed the following day when melatonin is no longer present [4].

The serum concentration of melatonin

Since the synthesis and secretion of melatonin are inhibited by light, the serum concentration of melatonin is higher at night (80-120 pg/ml) than at daytime (10-20 p g/ml) [2].

Did you know?
In an average adult human, about 30 mcg of melatonin is synthesized per day

Melatonin concentration in serum varies considerably with age. 

Newly born children secrete minimal amounts of melatonin. However, since the melatonin rhythm, and the sleep-wake cycle, becomes set at around 3 months of age, melatonin levels rise a little [2, 3].

The concentration of melatonin in our body at night peaks at around 1-3 years of age and gradually declines as we age [2].

Now that we’ve seen what melatonin is, what it does, and how it works, let’s have a look at what melatonin supplements are and how long melatonin effects last.

What are melatonin supplements?

Secretion of melatonin can be inhibited by many factors like 

  • light-including blue light, 
  • aging, 
  • stress, 
  • night shifts, 
  • less exposure to daylight, 
  • visually impairment etc

Low melatonin levels might cause sleep disturbances and are also related to mood disorders, cancer, type-2 diabetes, dementia, and several other conditions [10,11,12,13].

Melatonin dietary supplements are popular, readily available, and commonly used for preventing and treating sleep-related disorders including jet lag insomnia (trouble sleeping and staying asleep) [14].

Melatonin supplements are mostly in the form of [14].

  • capsules, 
  • tablets (slow-release, timed-release, sublingual, and chewable tablets), 
  • soft-gels, 
  • liquids, 
  • fast-dissolving strips, 
  • sprays
  • creams
  • anal suppositories and 
  • even capsules containing complex mixtures of vitamins, minerals, and plant extracts 

Melatonin supplements can be natural or synthetic. Natural melatonin supplements can be plant-based or made from the pineal glands of animals. How long melatonin effects last depends on the type of supplement you take.

What is a melatonin supplement used for?

In addition to the primary use of melatonin supplement for sleep, it has a lot of other potential applications like [7]

  • Inflammatory conditions
  • Hypertension
  • Metabolic Syndrome (Abdominal obesity, High blood pressure, high LDL cholesterol, high triglycerides, high fasting blood sugars)
  • Oxidative stress

How long does melatonin take to work?

There is a considerable variation in terms of rate of absorption, metabolism, and elimination of melatonin between different forms of melatonin and also between distinct individuals [7].

Immediate release melatonin supplements (regular melatonin tablets) are immediately released into your blood. Whereas extended-release melatonin supplements (prolonged or continuous-release melatonin) dissolve slowly and gradually release melatonin over time.

Most oral formulations reach their peak level within 60 minutes. Intravenous melatonin, however, will be rapidly distributed [2,3,7]. 

How much melatonin should you take?

One can find a large range of doses from 0.1 to 5 mg for treating sleep disorders. However, doses as high as 300 to 2000 mg are also available for managing other conditions.

Within an hour after ingesting a usual dose of about 1 to 5 mg, the serum melatonin concentration rises by 10 to 100 times the normal levels [2].

Average young people taking 0.1 to 0.3 mg of melatonin will have a physiological plasma concentration of 100-200 pg/ml (pg= picograms). But those taking 1mg would have a far higher plasma concentration of 500-600 pg/ml [4].

The selection of melatonin supplement dosage for sleep must be such that the nocturnal profile ends by the usual wake time of the patient. Thus, the dose and the formulation (slow, timed, or mixed release forms) must be carefully selected to not disturb the natural biological night of the patient [4].

It is best to consult your healthcare provider for choosing melatonin supplement dosage and getting the best melatonin supplement for sleep. 

When to take melatonin?

  • It is recommended that you take melatonin about an hour before bedtime since most oral melatonin supplements take about 45 minutes to an hour to become bioavailable. 
  • It is important that you rigorously maintain this timed, everyday intake [4].

How long melatonin effects last?

Though melatonin concentrations peak after taking a usual dose of melatonin supplements, they will drop to normal concentrations within 4 to 8 hours [2].

Melatonin once absorbed, will be rapidly metabolized, mainly in the liver and secondarily in the kidney, and excreted in the urine. 

It would take about 3-4 hours for regular melatonin to be eliminated from your body. But if you use a sustained-release (slow-release melatonin), it would take a while longer (6 to 8 hours) for it to leave your system [2, 3, 8].

How long melatonin effects last also depends on other factors like

  • Age
  • Frequency of using melatonin
  • Caffeine intake
  • Overall Health status
  • Body composition
  • Smoking 
  • Other medications

Is melatonin supplement safe?

Melatonin supplementation is generally considered safe and lacks toxic side effects. Short-term use of melatonin, even in extreme doses, is usually safe [4, 15].

What are the side effects of melatonin and precautions?

Though melatonin supplementation is usually safe, some people might experience some mild melatonin side effects like [4, 15, 16].

  • Nausea
  • Headache
  • Dizziness
  • Fatigue
  • Sleepiness or decrease in alertness
  • Anxiety
  • Depression
  • Mood changes etc.

However, since most side effects were reported in the placebo too, it is not sure if melatonin actually causes such mild-adverse effects.

A few groups of people like children, adolescents, older adults, those on medications must take caution before starting melatonin supplementation.

Children and adolescents: Since the long-term safety of melatonin in children and adolescents is yet to be clearly understood, it might be best to proceed with caution [15].

Interactions with medicines: 

A few drugs like fluvoxamine, oral contraceptives, and caffeine, if taken after exogenous melatonin supplementation can increase the plasma melatonin concentration. Cigarette smoking, drugs like cimetidine, psoralen, etc might also increase plasma melatonin levels [15].

A decrease in plasma melatonin levels can be caused by drugs like carbamazepine, rifampicin [15].

Melatonin supplement side effects might be caused when melatonin is taken in combination with hypnotics. The risk of adverse effects of melatonin when taken in combination with such drugs is not yet established.

So, it is of utmost importance to work with your healthcare provider before you finalize your best melatonin supplement.

Who takes melatonin?

Usually people with sleep disorders like insomnia or even jet lag take melatonin supplements. However, it is prescribed for many other conditions like for headache in adults, treating anxiety, depression, etc.

Who shouldn’t take melatonin?

Pregnant and lactating women: Since there are no human studies on the use of melatonin in pregnant and breastfeeding women, they must refrain from using exogenous melatonin [15].

How to Increase Melatonin Levels Naturally?

If you’re looking for ways to get melatonin naturally, consider yourself lucky because melatonin is found in a wide range of foods.

You might also find it interesting to know that melatonin content in plant foods varies from species to species and depends on many factors like the environment in which the plants were grown, duration of exposure to sunlight, ripening process, chemical treatments, etc [17]. 

Similarly, melatonin content in animal foods is also different in different individual animals of the same species.

Animal foods:

Eggs and fish have a higher concentration of melatonin when compared to meat. 

You can also find appreciable concentrations of melatonin in the breast milk of humans and that of other animals too. 

Plant foods:

Nuts and herbs have higher melatonin content than vegetables and fruits.


  • Pistachio (Pistacia vera L. cv. Fandoghi) was reported to have the highest melatonin content to date (233,000 ng/g DW)
  • You can also find a little amount of melatonin in walnuts.

Medicinal herbs: You can also get melatonin from herbs like 

Huang-qin (Scutellaria biacalensis) 7110 ng/g dry weight
St John’s Wort (flowers) (Hypericum perforatum) 4490 ng/g dry weight
Chantui (Periostracum cicadae) 3771 ng/g dry weight
Gouteng (Uncaria rhynchophylla) 2460 ng/g dry weight
Diding (Viola philipica Cav.) 2368 ng/g dry weight
Shiya tea-leaf (Babreum coscluea) 2120 ng/g dry weight
Black pepper (Piper nigrum L) 1008 ng/g dry weight
Mulberry leaves 40.7-279.6 ng/g dry weight

(Note: ng = nanograms)


A few kinds of cereals rich in melatonin are:

  • Wheat (124.7 ± 14.9 ng/g fresh weight)
  • Barley (82.3 ± 6.0 ng/g fresh weight)
  • Oats (90.6 ± 7.7 ng/g fresh weight)

Though melatonin is also found in rice, non-glutinous black rice has almost twice the melatonin concentration than in glutinous type. And the melatonin concentration in polished rice is one-third higher than that in whole rice.

Legumes and seeds:

You can find melatonin in many legumes and seeds like

  • White mustard seeds (189 ng/g dry weight)
  • Black mustard seeds (129 ng/g dry weight)

If you are looking to have legumes for getting melatonin naturally, it is best to have germinated legumes as germination greatly increases the melatonin content.

e.g., Germinating soybeans increases the melatonin concentration by 400%.


Melatonin is found in many fruits like 

  • Grapes (8.9 to 158.9 ng/g dry weight)
  • Cherries (13.46 ± 1.10 ng/g fresh weight) 
  • Strawberries (11.26 ± 0.13 ng/g fresh weight)

However, the melatonin content, as mentioned earlier, varies in different cultivars.


A lot of common vegetables have melatonin like:

  • Tomatoes (14.77 to 23.87 ng/g fresh weight or 250 ng/g dry weight)
  • Bell pepper (11.9 ng/g fresh weight or 93.4 ng/g dry weight)
  • Mushrooms (4300 to 12,900 ng/g dry weight)

In addition to the above-mentioned groups, it can also be found in juices, wine, beer, cacao, balsamic vinegar, edible oils like refined linseed, virgin soybean oil, extra virgin olive oil; yeast, etc [7, 17].


Q: What are melatonin patches?

A: Transdermal melatonin patches are similar to nicotine patches and can release melatonin into the body via the skin when applied.

Q: Do germinating soybeans increase the melatonin content?

A: Yes! Germinated soybeans have 400% more melatonin than dry soybeans

Q: Does bread have melatonin?

A: Yes, but bread crumbs have higher melatonin levels than the crust. 

Q: How long does melatonin stay in the body system?

A: It usually takes about 4-8 hours for melatonin to leave the body. 

Q: How to supplement with melatonin?

A: It is best to take melatonin supplements at least 1 hour before your bedtime.

Wrapping up

Melatonin dietary supplement helps with sleep disorders like insomnia or jet lag and many other health conditions. Melatonin side effects are minimal, if any.

Start with a small dose and take it 45 to 60 minutes before going to bed as it takes up to an hour for melatonin to start kicking in. How long melatonin effects last depends on the formulation and dosage used. It also varies depending on the individual.

Melatonin interacts with a few drugs and the effects of melatonin on a few groups like pregnant and breastfeeding women, children, etc has not been properly investigated.

So, you must talk to a healthcare professional to understand if melatonin is right for you, determine how much is the right dosage for you and whether there are any possible medical interactions. It is only then, you can get the best melatonin supplement.

What next? Learn more about

  1. What you need to know about Holistic health care
  2. 10 Health Benefits of Daily Yoga [with routine]
  3. What is functional nutrition and why should you care?
  4. Proven Essential Oils Benefits for Health


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