Melatonin, screen media, light and sexuality

Melatonin is a very important hormone secreted by the pineal gland in the brain (the seat of the soul, according to Descartes).  Since melatonin controls nearly every other hormone produced by the body, it is often defined as the master hormone.

Melatonin is involved in many physiological functions and has varied therapeutic applications: It acts as a neuroprotective; improves headache, bipolar disorders and ADHD symptoms; protects against Alzheimer’s disease; offers antioxidant properties; strengthens memory; improves cancer survival; protects from radiation; improves autism, and much more.

A 2012 study on obesity and diabets concludes that “epidemiological studies link short sleep duration and circadian disruption with higher risk of metabolic syndrome and diabetes” and “prolonged sleep restriction with concurrent circadian disruption alters metabolism and could increase the risk of obesity and diabetes.” (Buxton, 2012).

The popular use of melatonin supplements is for jet-lag symptoms, promoting sleep. Melatonin is produced by the pineal gland in darkness; thus, production takes place at night and is more pronounced in winter than in summer.

Being continually exposed to screen media and the light associated with it makes our brains believe it is still daytime.  Being exposed to such light during nighttime can disturb sleep patterns and trigger insomnia. While modern civilization has always used artificial light, the introduction of light-emitting laptops, tablet computers and smartphones created what Mercola (2011) defines on his website as “a state of permanent jet-lag.”  The light emitted by gadgets is much closer to us than ambient lights, which makes their melatonin-inhibiting action stronger.

Also, the type of light the screens emit makes a difference: Screen media mostly emit blue light, covering only a portion of the visible spectrum.  Our eyes are especially sensitive to blue light because it is the type of light normally found outdoors.  That way, gadgets can stop the production of melatonin needed for sleeping and for other health functions.  Among other risks, prolonged exposure to light can increase the risk of cancer.

Melatonin is also essential for healthy brain function, being one of the main endogenous brain antioxidants protecting the brain from free radicals.  Furthermore, there are connections between melatonin production and cognitive capabilities. Technology use, other than subtly affecting our psyches, has a direct physiological impact on our bodies, which, in turn, leads to changes in our inner attitudes.

Melatonin also has a strong connection with sexuality and sexual hormones. When melatonin levels rise in the body, usually in winter, testosterone levels drop, reducing sexual desire and frequency of mating.  For females, estrogen is also reduced. Just before puberty, melatonin levels drop suddenly by 75%, giving strong hints about the involvement of the hormone in the onset of puberty.

The last couple of decades saw a significant growth of precocious puberty, which, considering the concomitant massive use of screen media (video games, computers, Internet) by kids, can lead us to wonder whether there is a correlation between melatonin-inhibition by screen light and hormonal changes triggering early puberty.

Melatonin levels are inversely proportional to sexual desire and to the levels of sexual hormones.  Less melatonin, as when the production is inhibited by natural or screen light, increases sexual desire.  That’s probably good news for porn producers.


Mercola, F. (2011, January 10). The “sleep mistake” which boosts your risk of cancer.

Buxton, O.M., S. W. Cain, S. P. O’Connor, J. H. Porter, J. F. Duffy, W. Wang, C. A. Czeisler, S. A. Shea, Adverse Metabolic Consequences in Humans of Prolonged Sleep Restriction Combined with Circadian Disruption. Sci. Transl. Med. 4, 129ra43 (2012).

See also:

Close, Closer, Closest to the Screen

Per svariati impegni in questo periodo non riesco piu’ a gestire la doppia lingua. Poiche’ la maggior parte dei visitatori di questo blog arriva dall’estero, dovendo scegliere, ho optato temporaneamente per una lingua internationale. Credo che la maggior parte dei visitatori italiani di questo sito conosca l’inglese.

Clicca sulla bandierina britannica in alto a destra per l’articolo in inglese.

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