Melatonin

[[File:Melatonin.png|thumb|left|165px|Melatonin]]{{Biology}}
'''Melatonin''' (N-acetyl-5-methoxytryptamine) is a hormone found in a variety of species, and in [[mammals]], it is a part of the sleep-wake cycle.

==Actions==
Melatonin is secreted by the [[pineal gland]] in response to darkness, and production is inhibited by light (specifically light in the blue spectrum).<ref>[https://effectiviology.com/sleep-better-reduce-blue-light-before-bedtime/ Fall Asleep Faster and Sleep Better by Reducing Blue Light Exposure Before Bedtime]</ref> It promotes drowsiness and decreases {{wpl|libido}} in females by inhibiting the secretion of follicle stimulating hormone (FSH) and luteinising hormone (LH). Because of its proposed ability to promote [[sleep]], it has been used in sleeping tablets.

==As a sleep aid==
[[File:Walgreens Melatonin-2010-20-07.jpg|thumb|right|165px|Melatonin supplement]]
There are many melatonin supplements available sold as sleep aids, but, due to the lax regulation of supplements in general in the United States, most contain 10× or more the required dose and can actually prove to be counter-productive.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/12069043 Low, but not high, doses of melatonin entrained a free-running blind person with a long circadian period]</ref> A summary on the meta-analyses and systematic reviews of melatonin from 2014 concludes that the many studies that purport intended effects of melatonin are poorly-designed and show modest results at best.<ref>''Alberta College of Family Physicians'' (September 2, 2014). [https://www.acfp.ca/wp-content/uploads/tools-for-practice/1409669944_120tfpmelatoninfv2.pdf Tools for Practice].</ref> When regulated as a supplement, the melatonin bottles are wildly varied and often do not contain the correct amount of melatonin on the label,<ref>Gavura, S. (March 9, 2017). [https://sciencebasedmedicine.org/melatonin-whats-on-the-label-isnt-in-the-bottle/ Melatonin: What’s on the label isn’t in the bottle]. ''Science-Based Medicine''. Retrieved March 12, 2017.</ref> surprising no one who is familiar with how supplements are regulated in the United States (they aren't regulated that well). For example, some bottles advertised to contain 1.5 mg had samples measuring at nearly 9 mg of melatonin, a difference of over 450%. These variations range from 83% below claimed to 478% above claimed. Worse, some of the products may contain serotonin, not displayed on the label, and it can lead to problems including Serotonin syndrome. Other countries such as those in Europe, however, regulate melatonin as a drug, so it may have better results.

==Other medical correlation ==
The medical establishment has just begun its research into the effects of melatonin on the body's function, and correlative ([[Correlation does not imply causation|vs. causative]]) links have been established with a host of modern medical problems, including long-term clinical depression, migraines,<ref>http://www.ncbi.nlm.nih.gov/pubmed/21861099</ref> diabetes cycles,<ref> http://www.ncbi.nlm.nih.gov/pubmed/21860691</ref> attention deficit disorder in children,<ref>http://www.ncbi.nlm.nih.gov/pubmed/21859418</ref>, tinnitus,<ref>http://www.ncbi.nlm.nih.gov/pubmed/21859051</ref> weight-gain and loss, anxiety disorders, and even some [[cancer|cancers]].<ref>[http://www.medscape.com/viewarticle/707460 Shift Work and Cancer]</ref> It's unclear if these are correlations with the associated lack of sleep common to a lack of melatonin production, or with the chemical itself, but research on melatonin shows that modern interrupted sleep cycles have contributed greatly to our own medical bills.

==Night Milk==
A company in [[Germany]] has taken to milking cows in the early hours of the morning, producing milk that is purportedly 25x times higher in melatonin than regular milk.<ref>[http://www.guardian.co.uk/world/2010/oct/18/nocturnal-milk-night-insomnia-sleep German night milk may aid insomniacs]</ref> The milk is then marketed as "Night Milk" or "Nocturnal Milk" as a sleep aid.

==References==
{{reflist|2|80%}}

[[Category:Biochemistry]]
[[Category:Chemicals]]
[[Category:Medicine]]

Categories: Biochemistry, Chemicals, Medicine