July 21, 2026Wellness

Why is melatonin important for our sleep?

What is melatonin?

Melatonin is a hormone produced by pineal gland in our brain which is mainly activated in response to darkness. It plays an important role in the management of sleep-wake cycle as well as circadian rhythm.

Some facts about melatonin are:

• Melatonin is also known as the hormone of darkness

• It is secreted by the pineal gland on response to darkness

• Melatonin is synthesized from serotonin a neurotransmitter derived from Tryptophan through a cascade of enzymatic reactions

• Melatonin exerts its physiological effects through G protein coupled receptors like MT1 and MT2, where these 2 receptors help in maintaining the circadian rhythm, promote onset of sleep modulating biological responses like immune responses and thermoregulation.

Melatonin ensures that we are getting enough sleep, since our body needs a natural , chemical reminder to feel tired each night. A night of good rest and sleep benefits our whole body including:

• Hair

• Internal Organs

• Mental and emotional health

• Skin

Apart from this melatonin works on other organs of our body like the following:

• Melatonin aids in the maintenance of regular menstrual cycles

• It protects our brain health preventing the cells from breaking down

• It might have anti-ageing properties as well

Which foods make you rich in melatonin and those which disturbs them

Food rich in melatonin are as follows:

• Tart cherries as well as tart cherry juice

• Goji berries

• Eggs

• Milk

• Mushrooms

• Nuts as well as legumes

• Fish

Food items which disturb melatonin

• Cold drinks

• Coffee

• Tea

• Chocolate

Daily habits which promote melatonin production

• Receiving good light exposure in the mornings

• Limiting the bright light exposure in evenings

• Having a regular sleep schedule (Laguaite, 2026)

Melatonin production cascade

By now we know that melatonin is synthesized in the pineal gland of mammals and mainly regulated by the suprachiasmatic nucleus (SCN) of the hypothalamus.

This further helps in synchronizing endogenous circadian rhythms with the external light dark cycle. Light inhibits the pineal melatonin synthesis through the retina-SCN-sympathetic pathway. Pineal gland in our brain converts serotonin, an indoleamine neurotransmitter into melatonin through a series of enzymatic reactions

Melatonin is processed in our body in the following steps:

• Melatonin synthesis begins with tryptophan which undergoes hydroxylation via tryptophan hydroxylase forming 5 hydroxytryptophan

• Aromatic 1-amino acid decarboxylase converts 5 hydroxytryptophan into serotonin

• Acting as the substrate for melatonin synthesis serotonin undergoes acetylation as well as methylation producing melatonin.

Two major enzymes regulating this transformation are

1. Arylalkylamine N-acetyltransferase (AANAT)

2. Hydroxyindole-o-methyltransferase (HIOMT)

Surprisingly there is no recommended dietary allowance for melatonin. For melatonin supplements a dosage of 0.5 to 3 mg is sufficient for sleep related issues.

What is endogenous and exogenous melatonin?

The melatonin which is naturally produced by our body is known as endogenous melatonin. It helps in the regulation of our body’s natural sleep wake cycle and is involved in making us feel tired at the end of the day and especially waking up after resting. Melatonin synthetically sold in labs as dietary supplements is known as exogenous melatonin.

How does melatonin enhances sleep

Endogenous melatonin is a naturally produced hormone which is primarily synthesized and secreted in the pineal gland. Melatonin triggers sleep by binding to the MT1 as well as MT2 receptors, found throughout our body initiating sleepiness by lowering the body temperature thus causing drowsiness. The main role is in promoting sleep and inhibiting wake promoting signals through the interactions of these receptors.

Difference with sleeping pills

Melatonin is not equivalent to sleeping pills, most people think that taking melatonin will make them sleep whenever they want to. However, melatonin works differently from most prescribed sleeping medications because the primary role is to signal the body that it is nighttime which resets the timing of the body’s internal clock. It is a naturally produced hormone which unlike sleeping pills do not force you to sleep but gently prepares our body to embrace a night time mindset. Sleeping pills are specifically designed to facilitate falling asleep or staying asleep. They are occasionally prescribed for alleviate insomnia however they do not address the underlying causes of various sleep issues.

Sleeping pills are not a permanent solution in preparing your body into a state of calmness and sleepiness.

Why are melatonin supplements not good?

Melatonin supplements are synthetically produced in a lab. They are supposed to give the body more of the hormone which helps in sleep regulation. They have a hypnotic effect helping people go to sleep. According to some research studies, they have also have been instrumental in the treatment of sleep disorders like delayed sleep phase and they are found to provide relief from jet lag or insomnia.

However, unknown or increased production of melatonin by supplements is not beneficial always. Short term uses of melatonin supplements are still safe because there is very less evidence supporting the long-term use of melatonin. It have been found to interact with various types of medicines like:

• Anti-blood coagulants

• Medicine preventing seizures

• Birth control pills

• High blood pressure medicines

• Diabetes medicine

• Medications suppressing the immune system

• Medicines digested in the liver

Moreover melatonin supplements contain a fixed amount of melatonin while the needs vary in our body from day to day. Excess or limited melatonin amounts is very risky as some unknown doses of melatonin lead to less common side effects like:

• Nightmares

• Short term feelings of depression

• Irritability

• Stomach cramps

• Constipation

• Reduced appetitite

• Urinary incontinence

• Increased risk of falls

• Confusion

• Mood swing

• Reduced alertness (Bauer, 2025).

Research evidence on the role of melatonin in the management of sleep and circadian disorders

Various neurocognitive disorders indicate common symptoms like dysregulation of sleep and circadian rhythms among majority of the patients and melatonin secretion is directly connected to this disorders. Recent research confirms melatonin secretion in schizophrenia as well as neurocognitive disorders is mainly reduced due to a small volume and enlarged calcification of the pineal gland. Meanwhile melatonin dysregulation in bipolar disorder might be more dynamic caused mainly by light sensitive melatonin suppression as well as delayed melatonin secretion.

Exogenous melatonin seems to be correct this dysfunction however, a limited number of well-designed trials for correcting sleep and circadian rhythms exist in certain psychiatric disorders where the evidence for increased efficacy is robust only in autism, attention deficit hyperactivity disorder or ADHD as well as neurocognitive disorders. Recent studies in such psychiatric disorders report that melatonin could be effective in the improvement of sleep parameters like sleep onset latency, sleep efficiency as well as sleep quality (Moon et al., 2022).

Another meta-analysis study investigating the efficacy of melatonin as compared to placebo in the improvement of sleep parameters in patients with primary sleep disorders show that melatonin successfully decreases sleep onset latency, increases total sleep time, thus improving overall sleep quality (Ferracioli-Oda et al., 2013).