Melatonin: Difference between revisions

Melatonin is active and can be taken [[sublingually]] and [[buccaly]] by placing it into one's mouth and allowing it to absorb over a period of 15-25 minutes. It is less active when taken [[orally]].  

melatonin is a full agonist of melatonin receptor 1 (picomolar binding affinity) and melatonin receptor 2 (nanomolar binding affinity), both of which belong to the class of G-protein coupled receptors (GPCRs).<ref name=":0">J{{cite journal | vauthors=((Jockers, R.)), ((Delagrange, P.)), ((Dubocovich, M. L.)), ((Markus, R. P.)), ((Renault, N.)), ((Tosini, G.)), ((Cecon, E.)), ((Zlotos, D. P.)) | journal=British Journal of Pharmacology | title=Update on melatonin receptors: IUPHAR Review 20 | volume=173 | issue=18 | pages=2702–2725 | date= September 2016 | issn=1476-5381 | doi=10.1111/bph.13536}}</ref> Melatonin receptors 1 and 2 are both G_i/o-coupled GPCRs, although melatonin receptor 1 is also G_q-coupled.<ref name=":0" /> Melatonin also acts as a high-capacity free radical scavenger within mitochondria which also promotes the expression of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase via signal transduction through melatonin receptors.<ref name=":0" /><br />Melatonin is metabolized in the liver by cytochrome P450 enzyme CYP1A2 to 6-hydroxymelatonin. Metabolites are conjugated with sulfuric acid or glucuronic acid for excretion in the urine. 5% of melatonin is excreted in the urine as the unchanged drug.<ref>{{cite journal | vauthors=((Tordjman, S.)), ((Chokron, S.)), ((Delorme, R.)), ((Charrier, A.)), ((Bellissant, E.)), ((Jaafari, N.)), ((Fougerou, C.)) | journal=Current Neuropharmacology | title=Melatonin: Pharmacology, Functions and Therapeutic Benefits | volume=15 | issue=3 | pages=434–443 | date= April 2017 | issn=1875-6190 | doi=10.2174/1570159X14666161228122115}}</ref> Some of the metabolites formed via the reaction of melatonin with a free radical include cyclic 3-hydroxymelatonin, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), and N1-acetyl-5-methoxykynuramine (AMK).<ref name=":0" />

*'''[[Effect::Anxiety Suppression or Anxiety]]''' - Although this substance decreases anxiety with most people, it can also cause anxiety by some.

*'''[[Effect::Dream potentiation]]''' - Melatonin is extremely effective at increasing the duration, occurrence, and vividness of dreams. It is very common for people to note that their dreams had noticeably increased the morning after ingesting melatonin as a sleep aid. Melatonin is sometimes used to increase the chances of lucid dreaming.  

*'''Canada''': Melatonin is freely available to purchase as a dietary supplement and can be found at most pharmacies and grocery stores across the country.{{citation needed}}

*'''Switzerland''': Melatonin is listed as a "Abgabekategorie B" pharmaceutical, which generally requires a prescription.{{citation needed}}

*'''United Kingdom''': Melatonin is a licensed prescription-only medicine (POM) in the United Kingdom.{{citation needed}} It is not a criminal offense to possess this medicine without a valid prescription. This medicine can legally be obtained with a valid prescription or through legal import of the medicine for personal use as outlined in Section 13 of the Medicines Act 1968.<ref>{{cite web |url = http://www.legislation.gov.uk/ukpga/1968/67/section/13|title = Medicines Act 1968 Section 13}}</ref>

*'''United States''': Melatonin is listed as an uncontrolled substance and is legal to possess and distribute, and is freely available to purchase as a dietary supplement.{{citation needed}}