Melatonin Hormone

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Melatonin is known as the hormone of darkness as it is responsible for regulating the sleep and wake cycle.

What is Melatonin Hormone?

Melatonin hormone is synthesized by the pineal gland of the endocrine system. It is a small, pea-sized gland found behind the middle region of the brain. It functions by stimulating our body cells when it’s time to sleep and wake up. This hormone is secreted in response to darkness, hence the name hormone of darkness.

Normally, our body produces more melatonin during the nighttime. The hormone levels normally increase in the evening and drop in the morning as the sun rises.

During the daytime, the pineal gland is less active, and as the darkness occurs or during the night times, the pineal is active and produces melatonin, which is released into the blood. Melatonin levels in the blood stay elevated for about 12 hours – all through the night.

Melatonin is sometimes called the “Dracula of hormones” because it only comes out in the dark.

Also Read: Endocrine system

Functions of Melatonin Hormone

  1. It plays an influential role in the regulation of sleep cycles.
  2. It plays a role in regulating the female menstruation cycle.
  3. Melatonin hormone has a significant effect on affecting circadian rhythms and integrating photoperiod.
  4. It also has a significant effect on reproduction and other phenomena showing circadian rhythm.
  5. This hormone is also helpful for children with developmental disabilities such as ADHD and autism.
  6. It is often considered to be the body’s natural pacemaker, as it plays an instrumental role in signalling time of day and time of year, helping to regulate your body’s internal clock.

Also Read: Hormones

Hormone Levels

The changes in the melatonin hormone level are mainly caused by the malfunctioning of the pineal gland.

According to medical reports, the physiological levels of the melatonin hormone range from several pg/ml during the day to more than 50 pg/ml at night time.

The hormone levels vary with the sex, age and lifestyle of an individual.

The desired levels of hormones required for optimal function are:

At 12 midnight, the level should be between 10 – 40 pg/mL

At 6 am in the morning the level will be less than 4 to 3pg/mL. The value is usually measured in Picograms Per Millilitre.

The variation found in the melatonin hormone level can be associated with many health disorders and lifestyle changes. The responsible causes differ with the higher and lower level of the melatonin hormone.

The disorders caused by the malfunctioning of the pineal gland include:

  • Mood swings
  • Stomach ulcers
  • Sexual disorders
  • Hormonal imbalance
  • Disruption in sleep patterns

Low level of melatonin hormone

Low melatonin secretion leads to anxiety, low thyroid hormone production, menopause symptoms, mood swings, depression, etc.

The main factors for the decrease in the level of melatonin hormone include:

  1. Age
  2. Stress
  3. Lack of sleep
  4. Night shift work
  5. Excessive exercise at night
  6. A prolonged light phase of the day
  7. Increased metabolism by the liver
  8. Prolonged exposure to bright lights
  9. Decreased production by the pineal gland
  10. Intake of more coffee, tobacco and alcohol
  11. Side effects of certain drugs, including steroids

High level of melatonin hormone

High melatonin secretion leads to nausea, seizures, headache, mood swings, memory disruption, impaired vision and other senses.

The main factors for the increase in the level of melatonin hormone include:

  1. Extended nocturnal dark phase.
  2. Calcium and other supplements.
  3. Exposure to bright light in the morning.
  4. Decrease in the metabolic functions of the liver
  5. Side effects from certain drugs such as desipramine, fluvoxamine and MAO inhibitors.
  6. Intake of more melatonin or tryptophan supplementation, including Vitamin B3, B6, calcium etc.

Also Refer: Hormonal Imbalance

Measures to control the levels of melatonin hormone

There are a few factors which help in controlling the level of melatonin hormone in our body. These include:

  • Regular and adequate sleep
  • Intake of B12 supplementation
  • Decreased exercise during nighttime
  • Less exposure to bright light at nighttime
  • Reduce the intake of coffee, tobacco products, nicotine and alcohol
  • Having a regular and balanced diet strengthens the production of melatonin levels
  • Increase food sources high in tryptophan, such as bananas, seaweed, oats, turkey, chicken and other food rich in Vitamin B3, B6, calcium and magnesium

What is the Melatonin Test used for?

The melatonin test is a pathology test, which is used to check the level of melatonin hormone in the individual’s blood.

This blood test is usually prescribed by doctors to diagnose certain disorders, including:

  • Alzheimer’s disease
  • Amyotrophic lateral sclerosis (ALS)
  • High blood pressure during the night
  • Sleep problems in children with autism spectrum disorders

How to increase melatonin levels in the blood?

The melatonin levels in the blood can be increased naturally by maintaining a balanced diet, regular physical activities and by increasing the intake of a certain food, which can regulate melatonin levels, such as:

  • Fruits – berries, pineapple, bananas, cherries, oranges, pomegranate, etc.
  • Vegetables- corn, asparagus, tomatoes, olives, grapes, broccoli, cucumber, etc.
  • Seeds and nuts – walnuts, peanuts, flaxseed almonds, sunflower seeds, mustard seeds, etc.

Also Read: Nutrients

There are many melatonin supplements, which are available in the form of pills, liquids and chewable gums. These hormonal supplements are natural forms, which are made from the animal’s pineal gland and are used as medicines and supplementary sources of the melatonin hormone.

People use melatonin supplements when they have insomnia and other sleep disorders, such as delayed sleep phase disorder, waking up in the early hours of the morning before 4 am, trouble falling asleep and staying asleep, sleep work disorders, treatment or prevention of jet lag, feeling tough and tired while getting up in the morning and much more.

Read More: Hormones and Hormonal Disorders

This article concludes with the introduction to the melatonin hormone, its functions, disorders caused by its level of production and their symptoms.

To know more about the melatonin hormone, their types, functions, other related topics and important questions, keep visiting our website at BYJU’S Biology.

Frequently Asked Questions on Melatonin Hormone


What triggers melatonin release?

The production and release of melatonin hormones into the bloodstream are controlled by the pineal gland. These glands are active only during the night.


Does melatonin affect other hormones?

There is no clear evidence to prove the effects of melatonin on hormones. But according to the patient’s medical reports, melatonin may affect reproductive hormone levels in women and in some rare cases, it may interact with certain medicines.


Does melatonin increase estrogen?

Yes, the melatonin hormone is considered one of the factors responsible for the changes in the estrogen level in the blood cells. Higher levels of melatonin decrease the level of estrogen, and lower levels of melatonin increase the level of estrogen.


What foods have melatonin?

There are different sources of food, where melatonin hormone is found abundantly. This food source includes eggs, nuts, cereals, oats, cheese, legumes, fish and other food products rich in proteins and tryptophan.

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