Melatonin for Sleep – Uses, Side Effects and Contraindications

Melatonin is a naturally occurring hormone in the body which is secreted by the pineal gland of the brain. It is the “hormone of darkness” as it is secreted during the dark hours of the day to help us sleep and maintains the circadian rhythm of the body. The circadian rhythm is the internal biological clock of the body which induces sleep during night and wakefulness during the day.

Melatonin for Sleep 

Melatonin for sleep is also made synthetically in the laboratory. Melatonin supplements are available as melatonin oral pills, melatonin liquid or sublingual melatonin lozenges that  can be placed under the tongue. It is taken to induce sleep and adjust the biological clock of the body whenever it has been disturbed such as due to jet lag or changing working shifts. It is usually taken 2 to 4 hours before bedtime. This helps to induce sleep and increase sleep hours. Most sleep experts do not advise use of melatonin for more than two weeks. Any longer need of use requires that your insomnia be investigated for an insomnia cause.

Where Will You Get Melatonin

Melatonin is an over the counter natural sleep aid and is available in health stores, drug stores and department stores. You do not need a prescription to buy melatonin supplements.

Melatonin Synthesis in the Body

In the body, the precursor of melatonin is serotonin, a neurotransmitter, which is made from the amino acid tryptophan. The duration of secretion of melatonin is directly proportionate to the length of night.  A shorter night will see fewer hours of melatonin secretion.

Functions and Benefits of Melatonin

As mentioned above melatonin is a natural occurring hormone secreted by the pineal gland in the brain. It serves the following functions in the body.

  • Melatonin helps maintain the circadian rhythm of the body. Its secretion during the night helps to induce sleep.
  • Melatonin regulates the female reproductive hormones which determines the onset of menstruation, its frequency, its duration and also the onset of menopause.
  • Melatonin is a strong antioxidant which helps to strengthen the immune system of the body.
  • Some researchers believe that melatonin is related to the aging process because the levels of night-time melatonin levels are higher in younger people than in the elderly. Its levels are highest at the age of 20 years and falls to 20% by the age of 80 years. This could also be the reason why some elderly people sleep for lesser hours than when they were young.

Uses of Melatonin

Melatonin supplements are used for the following conditions.

  • Insomnia due to jet lag, changing shifts at work, old age and to treat insomnia due to sleep disorders which upset the circadian rhythm of the body.
  • For General Improvement of Sleep in healthy adults. This helps to induce sleep, and increase sleep hours.
  •  In withdrawal syndrome caused by stopping of benzodiazepines taken to promote sleep.
  • To increase the effectiveness of cancer therapies. This use still requires thorough evidence.
  • In Sunburn, melatonin can be used alone or in combination with vitamin E.
  • In Irritable bowel syndrome, melatonin helps to reduce the symptom of abdominal pain.
  • In Epilepsy, studies indicate that frequency of seizures were reduced but this study still requires more evidence.

Melatonin Side Effects

The side effects of melatonin supplements are few when taken in  low doses and for short-term up to three months. Adverse effects of melatonin supplements (with long-term use) are mentioned below and you should contact your doctor if you experience any of these when taking melatonin as changes in its dosage or its stoppage may be necessary.

  • Headache
  • Irritability
  • Dizziness,
  • Tremors
  • Abdominal cramps.
  • Drowsiness during the next day
  • Mood changes such as depression
  • Grogginess and confusion during the next day
  • Allergic reaction especially of the mouth, tongue and throat such as itching and swelling
  • Vivid dreams
  • Enlarged breasts in men (called gynecomastia) and decreased libido.
  • It can interfere with fertility in women.

Contraindications of Melatonin

If you have any of the following conditions you must consult your doctor before starting on melatonin supplements.

  • Allergy. – Stop melatonin if you develop allergy to it.
  • Diabetes. – Melatonin  can cause increase in blood sugar.
  • High blood pressure. – Melatonin can cause increase in blood pressure.
  • Liver disease
  • Immune disorders. – Its effects on patient’s with autoimmune disorders such as multiple sclerosis, psoriasis, Crohn’s disease, lupus and rheumatoid arthritis is not known.
  • Depression. – Melatonin can worsen the symptoms of depression.
  • Epilepsy. – Risk of seizures can increase with melatonin.
  • Pregnancy. – Safety of use during pregnancy is not established.
  • Lactation
  • Melatonin and Alcohol. Alcohol should be avoided when on melatonin supplements because alcohol is a nervous stimulant in smaller doses but depresses the nervous system later. This causes a disturbance in sleep patterns.

Melatonin and Children

Melatonin supplements for children should be avoided because of its effects on hormones which can disturb the development during adolescence. As it is, the brain of a normal and healthy child produces significant amounts of melatonin and the effects of giving extra amounts of melatonin on the development are still not fully understood.

Some data exists that melatonin may be helpful to induce sleep in children with developmental problems as in acoustic children, children with cerebral palsy and mental retardation.

Sleeplessness in children should be treated by following proper sleep hygiene measures first and if sleeping problems persist, advice should be taken from a sleep specialist.

Drug Interactions with melatonin

Melatonin should not be taken with the following medications.

  • Taking sedatives such as clonazepam (Klonopin), lorazepam (Ativan), phenobarbital (Donnatal), zolpidem (Ambien), and others with melatonin can cause too much sleepiness.
  • Birth control pills increase the melatonin production in the body. Therefore taking melatonin with them can increase melatonin levels in the body.
  • Taking caffeine when on melatonin decreases the effectiveness of the melatonin because caffeine decreases melatonin levels.
  • Antidiabetic medicines. Melatonin increases blood sugar and therefore reduces the effectiveness of these medications.
  • Immunosuppressants suppress the immune system and melatonin increases the immune system. The two therefore should not be taken together as the efficacy of the suppressants will be reduced.
  • Blood thinners such as warfarin should not be combined with melatonin as blood clotting time is considerably reduced and can cause bleeding.
  • Antidepressants
  • Corticosteroids
  • Benzodiazepines such valium
  • St John’s Wort.

Melatonin Dosage

Male adults need 150 micrograms while female adults need 100 micrograms. Tablets with these strengths may not be available and you may therefore have to break them up to get the required strength of dose.

The most commonly available melatonin tablets are of 3 mg strength. Melatonin 1 mg, 5 mg and 10 mg tablets are also available. Taking larger doses will be counterproductive. It is important to note that a time release melatonin pill should be not be broken as it will destroy the time release mechanism.

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