In detail

Melatonin: the hormone that helps us sleep

Melatonin: the hormone that helps us sleep

Melatonin is a hormone that generates the pineal gland, a small gland It is in the brain. Melatonin helps control sleep cycle - wakefulness. In very small quantities melatonin is found in foods such as meats, cereals, fruits and vegetables. It can also be purchased as a supplement in pharmacies and specialty stores.


  • 1 What is the function of melatonin?
  • 2 Clinical uses of melatonin
  • 3 Side effects of taking melatonin

What function does melatonin have?

Our body has its own internal clock that controls the natural sleep cycle as well as waking hours. In part, this biological clock It controls the amount of melatonin the body produces. Normally, melatonin levels begin to increase in the middle and end of the afternoon, remain high for most of the night, and then fall from the first hours of the morning.

The sunlight affects the amount of melatonin that our body produces. During the fall and winter months when the days are shorter, our body can produce melatonin earlier or later than usual. This change is said to cause symptoms of seasonal affective disorder or autumnal depression

Natural melatonin levels fall slowly with age. Many older people become very small "Naps‚ÄĚDuring the day and they don't sleep so many hours in a row at night.

Clinical uses of melatonin

Melatonin as we have explained, serves to adjust the internal clock of the body. In tablets it is sold as a natural product for fight insomnia, but it is also used to minimize the symptoms of jet lag, for adjust sleep-wake cycles in people whose work schedule changes (shift work disorder) make it difficult for them to sleep normally, and to help blind people establish the day and night cycle.

But melatonin can be prescribed for many other disorders, some people use melatonin for Alzheimer disease or memory loss (dementia), the Bipolar disorder, chronic obstructive pulmonary disease (COPD), insomnia caused by beta-blocker drugs that are used for high blood pressure, stress, depression, chronic fatigue syndrome (CFS), headaches and many other ailments.

Melatonin is also used to reduce some of the side effects of cancer treatment (chemotherapy) including weight loss, nerve pain and weakness.

Studies have shown that melatonin can reduce anxietyIt can also be absorbed through the mucosa under the tongue, so it is increasingly used in hospitals to calm people before receiving anesthesia for surgery. In comparison with the benzodiazepines, widely used in the treatment of anxiety in these cases, melatonin does not produce subsequent "hangover effects" has no known serious side effects.

Sometimes people apply melatonin to the skin to protect against sunburn.

Side effects of taking melatonin

In most cases, melatonin supplements are safe at low doses. However, before taking anything it is advisable to consult with our doctor.

Children and pregnant or nursing women should not take melatonin without first consulting a doctor first.

Melatonin has some side effects, but they disappear quickly when you stop taking the supplement. These effects may include:

  • Decrease in body temperature.
  • Vivid dreams.
  • Stun in the morning.
  • Small changes in blood pressure.

It is not convenient to drive or operate heavy machinery when taking melatonin.


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Bradford, H.F. (1988). Fundamentals of neurochemistry. Barcelona: Labor.

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Carpenter, M.B. (1994). Neuroanatomy Fundamentals Buenos Aires: Panamerican Editorial.

From April, A .; Ambrose, E .; De Blas, M.R .; Caminero, A .; From Pablo, J.M. i Sandoval, E. (eds) (1999). Biological basis of behavior. Madrid: Sanz and Torres.