This article could do with a bit of a reorganization: it moves freely from talking about naturally occurring melatonin to talking about melatonin taken as a sleep aid/dietary supplement. It's generally clear from context that, for example, the safety section is about the supplement... but other parts aren't as clear. -- Starwed 05:23, 1 October 2007 (UTC) reply

Good point, I've shifted the safety to be under medicinal use, rather than at same level as for physiological role. Also renamed section headers for a little greater clarity (under supplementation there is both proposed medical use and the "softer" dietary supplement use), and ensure does not seem as if yet approved (ie licensed) use medically outside of research studies. See this edit David Ruben ^Talk 22:04, 1 October 2007 (UTC) reply

Improved. But I think this is the first time I've heard of a medicinal supplement. What's that? Perhaps the cognac I use to help me get my evening pills down? But seriously. Wikipedia is supposed to be international. In most countries melatonin is either a totally unavailable hormone or a hormone available on prescription. All the talk of 'supplement' can only confuse.

Your last sentence (above) is a bit garbled, but it seems to be saying that melatonin is not (yet) used for treating patients. I'm a patient, not a research project, and I'm treated with melatonin. An importer/distributor told my pharmacist on the 'phone last week that there are a couple thousand sources for melatonin in the US. Even if he's exagerrating, all that exported hormone can't be going solely to research projects... Hordaland ( talk) 23:57, 26 November 2007 (UTC) reply

In the section on “biological clock” I intend to add this sentence immediately following “but over-illumination can create significant reduction in melatonin production.”; “Since it is blue light that suppresses melatonin (ref. 1) , wearing glasses that block blue light (ref. 2)in the evening can help maintain melatonin production.” The first reference is to Brainard’s 2001 paper PMID: 11487664 that identifies blue light as the cause of melatonin suppression and the second reference is to Kayumov’s paper PMID: 15713707 in which he showed glasses that block blue light allow melatonin to flow, despite exposure to bright light. Are there any objections to my doing so? Rhansler 13:54, 2 November 2007 (UTC) Rhansler reply

OK by me, not that I've been active here. One caveat. Blue light is not the only light which suppresses melatonin, and there is some evidence that it's not even the most important in the elderly. Old eyes yellow, and block blue light to some extent. Hordaland 14:03, 2 November 2007 (UTC) reply

In view of the above I think I will add a qualifying word along with blue light to read "principally blue light". Rhansler Rhansler 02:41, 5 November 2007 (UTC) Rhansler —Preceding unsigned comment added by Rhansler ( talk • contribs) 21:39, 4 November 2007 (UTC) reply

If I put in in this format will it work? Since it is principally blue light that suppresses melatonin PMID: 11487664, wearing glasses that block blue light PMID: 15713707 in the hours before bedtime can help maintain melatonin production. Rhansler 18:26, 6 November 2007 (UTC) Rhansler reply

I feel that this section is oddly misplaced at the end instead of near the beginning of the article. Melatonin plays a tremendous role wrt seasonality, reproduction etc in many animals. The section looks like an afterthought. It would IMO be better moved to right after Production and Distribution.

Its name is perhaps a bit odd, too. Role in the study of zoology, or role in the animal kingdom? Hordaland 09:43, 5 November 2007 (UTC) reply

No objection, so I moved and renamed it as suggested. Hordaland 18:40, 8 November 2007 (UTC) reply

The John Hammell reference may be seriously meant, but it reads like a parody. The following article from The Independent may be a better (as well as newer) source: http://news.independent.co.uk/health/article118214.ece Hordaland 18:35, 8 November 2007 (UTC) reply

The primary basic funtion of melatonin is not that of an anti-oxidant. Many related molecules can exert similar anti-oxidant activity (Proc Natl Acad Sci U S A. 1990 Apr;87(7):2506-10. Antioxidant activities of some tryptophan metabolites: possible implication for inflammatory diseases.Christen S, Peterhans E, Stocker R.

The basic melatonin function is to tell the body the time of the day and of the year by acting on high affinity receptors. Accordin to the existing evidence, melatonin is just one of the many anti-oxidant molecules —Preceding unsigned comment added by 193.246.191.129 ( talk) 13:54, 22 November 2007 (UTC) reply

A paragraph, see below, was recently added to the Biological Clock (in humans) section about melatonin's effect on the hormone Leptin and on appetite. This was sadly misplaced. I added a short mention of and link to Leptin in the section on the animal kingdom and added (moved) the reference to the article on Leptin. If more of the removed paragraph should appear in the Melatonin article, it should be added in a relevant section. The removed paragraph was this:

Affects on Appetite: Leptin is a hormone that is synthesized in adipose tissue that is produced in direct proportion to fat stores within the body. Elevated levels of serum leptin result in a decrease in appetite. Melatonin receptors have been found in adipose tissue which, upon stimulation by melatonin acting in concert with insulin, increase production of leptin (Alonso-Vale, M.I., Andreotti, S., Peres, S.B., Anhe, G.F., Borges-Silva, C.N., Neto, J.C. & Lima, F.B. (2004). American Journal of Physiology-Endocrinology and Metabolism: November 30, 2004. Retrieved Dec. 15, 2007 from http://ajpendo.physiology.org/cgi/content/short/00478.2004v1.). Therfore, the net effect is that elevated levels of melatonin decrease appetite. —Preceding unsigned comment added by Hordaland ( talk • contribs) 22:55, 15 December 2007 (UTC) reply

It would be good if someone could find a source for this. The article said that melatonin was not available over-the-counter in the EU. An anon has recently changed this, commenting "Melatonin is sold OTC in many EU countries". I know that it's not OTC in Sweden nor UK. How to find out if there's an EU policy on this? Or a listing of other countries outside of EU? -- Hordaland ( talk) 19:20, 5 January 2008 (UTC) reply

Yes, As far as I know it is not OTC in the UK. SpangleJ - UK Spanglej ( talk) 20:19, 5 April 2009 (UTC) reply

The article mentions that tinted glasses can be worn in order to promote melatonin production. I believe, however, that the melatonin-light interaction occurs in all the skin, so mostly has nothing to do with the eyes. Would someone with more knowledge confirm or deny my suspicion? —Preceding unsigned comment added by 75.31.242.30 ( talk) 04:30, 6 January 2008 (UTC) reply

I suspect you may be confusing melatonin with melanin? In mammals, melatonin is produced in the pineal gland in the brain. Production of it is stopped by light striking the retina, specifically the 2% of ganglion cells in the retina which contain melanopsin. We have melanin in our skin, but not melatonin nor melanopsin. -- Hordaland ( talk) 09:35, 6 January 2008 (UTC) reply

This article is now the new Pharmacology Collaboration of the Month. Hopefully, it can be improved to featured or good article status. Dr. Cash ( talk) 17:32, 14 January 2008 (UTC) reply

Melatonin taken in combination with monoamine oxidase inhibitors (MAOIs) can lead to overdose because MAOIs inhibit the breakdown of melatonin by the body.[citation needed]

Removing this sentence. It's been discussed since 12/05 December 2005 (see above archive), and still no source. It's also not entirely clear on overdose of what? Overdosing on melatonin is unheard of. -- Hordaland ( talk) 00:01, 17 January 2008 (UTC) reply

The International Agency for Research on Cancer, announced through a press release in December 2007 that shiftwork that involves circadian disruption is “probably carcinogenic to humans”.

They reviewed epidemiological studies of long-term female night shiftworkers and noted a higher risk of breast cancer risk than those who did not work at night. These studies have involved mainly nurses and flight attendants. Animal studies had similar results where light at night significantly increased tumours. This relates to melatonin in that studies reducing levels of this hormone at night increased the tumours.

The IARC committee head noted that nearly 20% of the working population in Europe and North America are engaged in shiftwork, with many workers in health-care and transportation fiels as well as in industrial, communications, and hospitality sectors. Studies focussed on breast cancer in nurses and flight attendants.

70.51.93.236 ( talk) 00:16, 24 February 2008 (UTC)Lorraine Davison 70.51.93.236 ( talk) 00:16, 24 February 2008 (UTC) reply

Another interesting review on detrimental effects of light at night, including but not limited to general light pollution, on wild animals as well as humans:

Navara, Kristen J. (2007). "The dark side of light at night: physiological, epidemiological, and ecological consequences" (Review, PDF: full text). J. Pineal Res. (43): 215–224. doi: 10.1111/j.1600-079X.2007.00473.x. Retrieved 2008-05-07. {{ cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) ( help)

-- Hordaland ( talk) 04:16, 7 May 2008 (UTC) reply

"Until recent history, humans in temperate climates were exposed to up to 18 hours of darkness in the winter" Didn't people gather around camp fires for lighting and warmth in the winter? -- Phenylalanine ( talk) 21:08, 1 March 2008 (UTC) reply

Was this a sneaky edit, or what:

"Until recent history, humans in temperate climates were exposed to only about six hours of daylight in the winter."

Later in the same paragraph, it is pointed out that "it is principally blue light that suppresses melatonin", so the red-orange-yellow of campfires, candles and oil lamps had little effect on levels of melatonin in the blood. I'm hoping it's not necessary to specify this in this section. -- Hordaland ( talk) 22:12, 1 March 2008 (UTC) reply

Greetings,

I posted an external link and it was deleted. I would respectfully like to request feedback on this.

The link was on melatonin and insomnia.

I felt it was valuable because the article to which I linked:

• addresses perhaps the most common issue laypeople wonder and hear about when it comes to melatonin--and an issue that the Wikipedia article does not delve too deeply into--particularly in a way that laypeople can understand.

• provides an unbiased, evidence-based look at the supplement, written by a respected integrative physician.

The user who deleted it said it "Violates WP:COI, WP:ADVERT, etc." I understand this point of view but respectfully disagree with it. I am connected with the magazine that published the article, but I am not going around posting arbitrary links to our magazine. I have, in fact, only posted one other (which the same user deleted for the same reason--and with whose decision I disagree for the same reason). In my short time so far with Wikipedia, I have also made other edits to articles and have posted links to other external sites with which I have no connection.

Wikipedia does not disallow posting links to anything at all with which you are connected. It disallows abuse in this area. I believe a reasonable litmus test is: If the poster weren't connected to the organization, would the link be valuable?

I contend, very strongly, yes. And the Wikipedia community and readers shouldn't be denied valuable information that fills in gaps just because I was the user who posted it.

I am very careful not to post links that are not intrinsically valuable. If I do violate that policy, I of course invite anyone to take me to task. But could I please get some feedback on this issue? I would like to repost the link.

Thank you.

MyFamilyDoctorMag ( talk) 22:22, 21 March 2008 (UTC) reply

I deleted the link. One of the strong rules in Wikipedia is that people can't link to their own web sites, under WP:COI, WP:ADVERT, and other rules, and for good reason. If we let people link to their own web sites, every entry would get spammed by people who are trying to promote their sites. Everybody thinks their own work is useful, but you can't be a good judge of your own case.

The only exception is that you can identify yourself, and suggest a link in Talk. If other people think it's useful, somebody will add it. (I don't expect that to happen, but that's just my prediction.)

In practice, if you link to your own site, the link will get quickly reverted (particularly on medical pages). If you continually repost the links, you'll get blocked.

I'm reluctant to get into the merits of the article on MyFamilyDoctorMag, because it's so clearly unacceptable for other reasons. But on the merits, there was nothing in the article that isn't already in the WP entry. The next thing I looked at were the links. The link to the NINDS didn't even link to the melatonin or sleep pages on NINDS where you could get specific information on the subject, but just to the home page. The next link was to the Rozerem consumer page, with the obnoxious ad. The next link was to the MIT study, which was already discussed in the WP entry, with links to admittedly difficult journal articles. It is useful to add a plain-language summary to the WP entry, but only as a link where the WP entry already discusses it. Rather than linking to the MyFamilyDoctorMag article, where the only useful thing is the link to the MIT press release, when you can link to the MIT press release directly? Then at least you wouldn't have a WP:COI. If I wanted to link to a layman's description of sleep problems, I'd link to the Merck Manual, or the UK NHS patient material, or the NIH, or one of the academic web sites.

So whether you're connected with the site or not, I don't think it's valuable. You may disagree, and I'll probably never convince you, and that's why we use the rule against conflicts of interest.

I appreciate the needs of doctors to market themselves on the web. But you can't do it on Wikipedia. Sorry. Nbauman ( talk) 04:11, 22 March 2008 (UTC) reply

Nbauman,

If the policy is truly as you state, then the Wikipedia page on that policy needs to be edited. As it is written, it does not have these hard-and-fast rules you cite. It warns against abuse but does not say you cannot link to an appropriate site with which you happen to be associated.

You are also sorely misrepresenting the article to which I linked. "There was nothing in the article that isn't already in the WP entry." That is not true. In addition, the Wikipedia entry is completely academic and incomprehensible to the regular person. You seem to be very ready to trash any article other than the ones over which you lord (since you also trashed the other article to which I linked on another page), but anyone looking for readable melatonin information will not find it here. Therefore, the options are: 1) completely rewrite the Wikipedia article or 2) link to external options that give nonscientists reliable, readable information.

Further, you misrepresent the links in the JHMFD article. The links are appropriate in the context in which they appear. You also omit the fact that the article links directly to safety information from the NIH and NLM.

"If you continually repost the links, you'll get blocked." I did not repost the links but appropriately went straight to the talk page to ask for feedback. But I recognize a bullying threat when I hear it. Fortunately, you are not the be all and end all of Wikipedia, and I am happy to take this discussion to the next step.

I will await further input from others, however.

MyFamilyDoctorMag ( talk) 05:02, 22 March 2008 (UTC) reply

IMO, ask-the-doctor type sites are only very rarely acceptable as External links. They can more often, though carefully, be used as an inline ref for a specific claim. The one in question does not belong in External links (again: IMO). As an aside, I do appreciate MFDM's openness about her/his connections.

MFDM's criticisms of the article are valid. I quote:

... anyone looking for readable melatonin information will not find it here. Therefore, the options are: 1) completely rewrite the Wikipedia article or 2) link to external options ...

In principle and in practice, option 1 is best, and it's been needed for some time. It may be the usual thing in articles about hormones to open with very technical stuff. In this case, because of media interest the last decade or so and the OTC availability of the drug in many countries, I believe that this particular article should open with simple English explanations.

The article appears to have grown by bits here and there, without much plan. It has recently been a collaboration of the month project, and the result is embarrassing for Wikipedia. -- Hordaland ( talk) 11:26, 22 March 2008 (UTC) reply

I have long been an advocate of writing Wikipedia medicine and biomedicine articles to make them easier for the intelligent lay reader to understand.

Many WP articles are literally written by scientists for other scientists. On the one hand, they have a lot of good information. On the other hand, we get messages in Talk from people who say that they can't understand them.

I usually point to the model of The Merck Manual, Science magazine, etc. as examples of how you can be precise and accurate enough to satisfy scientists, yet be understandable to the intelligent lay reader. There is actually quite a bit of academic literature on what works and what doesn't work.

The best way, I think, is to add (not replace) layman's terms when you have technical terms. If you took a class on composition you learned about introductory sentences, and I think every paragraph, no matter how complicated, should have a simple introductory sentence that tells you what the paragraph is going to say. Sometimes you wind up with stuff that is important but unavoidably difficult, and I put that at the end. Medical editing is hard because you have to check back with the original sources to make sure your rewrite is still representing them accurately. Once you've done that, you can go to work on organizing the work as a whole, filling in the gaps, and deleting the less important material (not what you think is less important; what everybody thinks is less important).

This is a long, hard process, and it takes a lot of judgment. (There's a reason why medical editors get paid a lot.) I'd estimate it would take me a full day to edit a WP article like this to make it as understandable as a Science magazine article.

That's why so many of these WP articles look the way they do. But you're not going to make an article easier to understand by linking to your own web site. Nbauman ( talk) 14:24, 22 March 2008 (UTC) reply

Hordaland,

Thank you very much for weighing in. I appreciate your fair-minded input--and for noticing that I have been transparent.

When I posted the external link, I did not think the option of rewriting the Wikipedia entry was viable. For one thing, it would take so long, as Nbauman notes. But for another thing, I assumed the article must have been written that way for a reason--to reach scientists or something. I would not have been so presumptuous as to swoop in and start rewriting just because I'm used to dealing with a different audience. Instead, I added three links (not just the deleted one) that I thought provided easy-to-understand but reliable, evidence-based information, to help laypeople who might stumble across the article. But I understand now that I was mistaken in my assumption; the article can be rewritten.

Nbauman, after thinking it through, I understand your points better now, and I realize I should have come to the talk page before, rather than after, posting the link. Lesson learned. I do harbor some bitterness about this process, though--especially because of the insults that were made (and based on what I see as unfair assessments--particularly in the immune-system article, which was said to have been scraped from another site; that wasn't true at all!). And I still contend that in this article--the way it is written now--the link did improve it. It served the readers by giving them reliable, evidence-based, but readable information on perhaps the most popular melatonin topic among the general public these days. If the article already had that information in a form that was understandable, I would agree with you; my link would not have been necessary.

Anyway, Hordaland, I appreciate your coming in and diffusing the situation a bit.

I don't think I'll be doing much more with Wikipedia in the near future. I don't need this type of drama. I will thus leave this page to you guys. I would propose that even if the insomnia/melatonin link I provided is not acceptable, something would be better than nothing in the interim during which the Wikipedia piece is being revamped.

MyFamilyDoctorMag ( talk) 21:41, 22 March 2008 (UTC) reply

It is confusing to read these one after the other in just 2 paragraphs:
"A 2006 review found that although it is safe for short term use (of three months or less), there is "no evidence that melatonin is effective in treating secondary sleep disorders or sleep disorders accompanying sleep restriction, such as jet lag and shiftwork disorder."
X
"It appears to have some use against other circadian rhythm sleep disorders as well, such as jet lag and the problems of people who work rotating or night shifts."
IIIIIIIII ( talk) 00:01, 19 December 2012 (UTC) reply

In addition, http://www.ncbi.nlm.nih.gov/pubmed/12076414 concludes "Melatonin is remarkably effective in preventing or reducing jet-lag [details omitted]" Who to believe? Yoyo Wing ( talk) 05:25, 17 March 2015 (UTC) reply

I am confused by the statement "Melatonin regulates leptin, lowering it" when the article on Leptin says it is high at night, possibly lowering appetite during sleep. In fact I find contradictions is nearly every article I read involving regulation of one hormone or neuro-transmitter by another. It seems to be a confused mess. RDXelectric ( talk) 23:54, 14 July 2017 (UTC) reply

This article seems to be overwhelmed with Exogenous and Medical uses. Couldn't these go in a separate article? I don't know if that's practical, but maybe something to discuss? Zyxwv99 ( talk) 22:52, 15 November 2015 (UTC) reply

That is one possibility. However, I think that moving some sections around may avoid confusion. Processes in nature first, like any article about a hormone, followed by medical use. At present these things are not kept separate. -- Hordaland ( talk) 03:10, 27 January 2016 (UTC) reply

http://www.nlm.nih.gov/medlineplus/druginfo/natural/940.html#DrugInteractions - link returns 404. <<== unsigned edit by IP 63.87.61.109

I've replaced the deadlink with a ref from Univ. of Maryland. -- Hordaland ( talk) 02:29, 27 January 2016 (UTC) reply

Although I cannot quote any reliable sources, Melatonin tablets are freely sold across most of Eastern Europe. There is also an sublingual composition marketed as Somni-X. It is a fast onset spray, applied under the tongue. -- lasombra bg ( talk) 21:45, 16 September 2016 (UTC) reply

That Melatonin acts as a neurotransmitter is implicit on this page in that it's part of the "neurotransmitters" series, and also that the *effects* of Melatonin receptors being engaged is described in the "Functions" section, however it is never clearly stated. See: Serotonin page functions section. -- Whilom Chime ( talk) 17:09, 4 December 2016 (UTC) reply

It is actually a hormone, not a neurotransmitter that has effects on more distant cells, not just adjacent cells connected by synapses. I have edited the lead so that it now stated that it is a hormone in the lead sentence. Boghog ( talk) 18:54, 4 December 2016 (UTC) reply

Apologies, I certainly didn't mean to imply that it isn't a hormone, but that like norepinephrine it is both. I'm definitely not an expert, but I'm assuming its activity with Melatonin receptors in the suprachiasmatic nuclei of the hypothalamus means that it is also a neurotransmitter. I'm quite willing to be educated that it is not, but if that's the case it should be removed from the neurotransmitter page and the neurotransmitter list.-- Whilom Chime ( talk) 20:14, 4 December 2016 (UTC) reply

No problem. I am not an expert either. The sources that I have read invariably describe melatonin as a (neuro)hormone that is synthesized in the pineal gland. For melatonin to be classified as a neurotransmitter, it would also need to be released from presynaptic neurons and I can find no support for that in the literature. Hence as you suggest, I think melatonin should be removed from the {{ Neurotransmitters}} navbox and neurotransmitter article. Boghog ( talk) 06:12, 5 December 2016 (UTC) reply

Here's the article: https://www.ncbi.nlm.nih.gov/pubmed/28648359 I don't want to edit the part of the article which says that there's not enough evidence for this myself owing to my very limited knowledge of such subjects, but perhaps that should be done if that review article is right. Dakane2 ( talk) 19:37, 23 January 2018 (UTC) reply

There are quite a few side effects listed under medical uses. Perhaps these categories should simoly be combined into "Medical uses and side effects". Dig _deeper ^talk 04:11, 1 March 2018 (UTC) reply

@ Emh975: Can you proofread what you added? There's grammar mistakes and omissions (e.g., the bioavailability statement says "is between to and 50%" and doesn't specify a route of administration). Also, can you move the content you added in Melatonin#Pharmacodynamics to Melatonin#Biosynthesis and Melatonin#Regulation? Also, keep in mind that some of what you added is already covered there. Seppi333 ( Insert 2¢) 20:13, 29 January 2019 (UTC) reply

IMO this is better "Melatonin is a hormone, produced primarily by the pineal gland, which regulates wakefulness"

Than "Melatonin is a hormone and free radical scavenger that regulates sleep-wake cycles and functions as a mitochondrial antioxidant"

The ref is not very definitive says "targeted to the mitochondria where it seems to function as an apex antioxidant" [1]

And this ref "Evidence has emerged to show that both mitochondria and chloroplasts may have the capacity to synthesize and metabolize melatonin." [2]

Hardly definitive and as such IMO belongs lower in the body. Doc James ( talk · contribs · email) 02:38, 1 February 2019 (UTC) reply

Seems fair. The only reason I edited the lead is because of the phrase "primarily by the pineal gland" - will cut that. Also, melatonin doesn't regulate wakefulness; it regulates sleep-wake cycles. They're not the same thing. Seppi333 ( Insert 2¢) 05:17, 1 February 2019 (UTC) reply

What is wrong with "primarily by the pineal gland"? Yes it may be produced by other locations but it is primarily by the pineal no? Doc James ( talk · contribs · email) 05:52, 1 February 2019 (UTC) reply

Based upon the references I've read, I think the only thing that can be said for certain is that melatonin which circulates in plasma (i.e, secreted/hormonal melatonin) is primarily synthesized in the pineal gland. Pinealectomy appears to increase its concentration in some fluid compartments. Seppi333 ( Insert 2¢) 06:02, 1 February 2019 (UTC) reply

This ref says it is primarily made by the pineal gland. [3] Yes it might be made by other locations aswell.

But we have lots of refs that say that [4] Doc James ( talk · contribs · email) 06:04, 1 February 2019 (UTC) reply

Then just clarify that melatonin which circulates in the blood stream is produced in the pineal gland. That's the only gland that produces and secretes it as a hormone. Seppi333 ( Insert 2¢) 06:06, 1 February 2019 (UTC) reply

Okay so at least the hormone version is primarily from the pineal than. Have clarified. Doc James ( talk · contribs · email) 06:14, 1 February 2019 (UTC) reply

That seems fine. Seppi333 ( Insert 2¢) 06:22, 1 February 2019 (UTC) reply

User:Circleofpink This article is not about have sleep disorder are or are not a "grave public health crisis"...

There are also concerns that Frontiers is a predatory publisher.

And we already discuss sleep disorders with better references. Why a 2004 review when 2015 AHRQ reviews are avaliable? Doc James ( talk · contribs · email) 11:47, 24 January 2020 (UTC) reply

Secondary sleep disorders

Somnipathy, or sleep disorders, are a familiar yet grave public health crisis that can be addressed with timely and effective pharmacological and/or non-pharmacological – and sometimes a combination of the two – treatments. ^[1] With the disadvantage of poor compliance to traditional pharmacological therapy coupled with the increasing complexity of multifaceted non-drug sleep therapies to suit individual needs, the exogenous administration of melatonin – an endogenous, naturally-produced hormone in the human body involved in sleep regulation – is looked at as a potential solution to secondary somnipathy, sleep disorders caused by another existing medical or psychological condition. ^[1] Melatonin has long been used to treat various insomnias (problems with falling and/or staying asleep) and delayed sleep phase disorder. ^[2] In 2004, a review of 30 randomized-controlled trial studies revealed that specifically to secondary sleep disorders, melatonin did not significantly have any effect neither on sleep onset latency (SOL), on wake after sleep onset (WASO), nor on the percentage of time spent in REM sleep. ^[3] However, melatonin did significantly increase sleep efficiency and total sleep time (TST) in people with secondary sleep disorders. ^[3]

And we provide a better summary of the evidence. Doc James ( talk · contribs · email) 11:47, 24 January 2020 (UTC) reply

Alzheimer's disease

Hypothalamic nuclei, such as the suprachiasmatic nuclei and the lateral hypothalamic area, that are affected by β-amyloid plaques and neurofilament tangles in brains with Alzheimer's diseases are also involved in the severe disruption of the circadian rhythm and consequently, the occurrence of sleep disorders. ^[1] Sleep disturbances as well as poor sleep quality may contribute to the development of Alzheimer's disease, to some degree through the facilitation of β-amyloid buildup (a risk factor for Alzheimer's disease) in the human brain. ^{[2] [3]} Research shows that in the pre-onset stages of Alzheimer's disease, melatonin levels in the CSF are significantly lower. ^[1] Furthermore, there is evidence in transgenic animal models of Alzheimer's disease that the exogenous administration of melatonin not only decreases the production and/or deposition of β-amyloid peptide but also increases its clearance through the glymphatic system. ^[4] Recent research concluded that exogenous melatonin administered in the preclinical phase of dementia demonstrates a significant increase in sleep quality and efficiency. ^[1]

The ordering of this article follows WP:MEDMOS and has for some time. So restored. Doc James ( talk · contribs · email) 16:44, 29 March 2020 (UTC) reply

"Melatonin is rapidly absorbed and distributed, reaching peak plasma concentrations after 60 minutes of administration, and is then eliminated. Melatonin has a half life of 35–50 minutes."

How does that work? — Preceding unsigned comment added by Drsruli ( talk • contribs) 14:47, 22 July 2019 (UTC) reply

I think that the section should be removed. — Preceding unsigned comment added by 97.113.124.116 ( talk) 05:47, 3 August 2020 (UTC) I agree that the research is too preliminary for an encyclopedia article and I deleted the entire section. Tachyon ( talk) 12:38, 3 August 2020 (UTC) reply