Melatonin Hormone

The pineal gland of the human body produces melatonin. The pineal gland is a pea sized organ that resides just above the middle of your brain. The pineal gland is usually inactive during the day. As soon as the sun goes down and darkness sets in, the pineal gland “turns on” and produces melatonin, which is released into the blood stream. This event usually occurs around9 PM. The sudden increase in melatonin levels make you feel less alert and sleepy. Blood melatonin levels will stay elevated for approximately 12 Hours throughout the night. Daylight will trigger the body to reduce melatonin production. The daytime level of melatonin is barely detectable.

Bright light directly inhibits the production and release of melatonin. This is the reason why sometimes melatonin is called the “Dracula of Hormones”. Melatonin only comes out at night. In addition to the light coming from the sun, artificial lighting can be very bright that it prevents the release of melatonin. Melatonin released at night varies among individuals. It is also age related. Children have more melatonin compared to adults and it decreases with age. The cycle of waking up during the day and sleeping at night is a part of our life. Only recently did scientists begun to fully understand the cycle of waking and sleep, and how daylight and darkness affect this cycle.

When the level of melatonin in the body is too low or the melatonin level at night is inadequate, sleeping can be difficult. There are studies showing that the use of melatonin can shorten the time it takes to fall asleep as well as reducing the number of awakenings.  Melatonin might also help shift workers who constantly need to adjust their working schedules. Melatonin can delay or advance the sleep-wake cycle when you take it in low doses at the appropriate time. Even if melatonin is a natural substance, melatonin side effects are still observed among melatonin supplement users.

Melatonin References:

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Melatonin and Jet Lag: Confirmatory Result Using a Simplified Protocol. Biological Psychiatry, 32,
Jan, J. (1994). The Treatment of Sleep Disorders With Melatonin.

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Lino, A., Silvy, S., Condorelli, L., & Rusconi, A. (1993). Melatonin and Jet Lag: Treatment Schedule. Biological Psychiatry, 34, 587.

Zhdanova, I. (1995). Sleep – inducing effects of low doses of melatonin ingested in the evening. Clinical Pharmacology & Therapeutics, 57, 552-558.

Arendt J. Melatonin. Clin Endocrinol . 1988;29:205-229.
Borbely AA. Commentary on the articles by Arendt, Weaver, Mahle, et al, and Guardiola-Lemaitre. J Biol Rhythms . 1997;12:707-708.

Pharmacology and physiology of melatonin in the reduction of oxidative stress in vivo. Biol Signals Recept 2000 May-Aug; 9(3-4):160-71.

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