"A perfect sleeping pill  one that gets people to fall asleep faster and for a longer period of time with no side effects  is still a dream. Such a magic pill could potentially solve many problems. Millions of Americans dont get enough sleep. In a recent http survey the Centers for Disease Control and Prevention found that  percent of Americans are sleeping fewer than seven hours per night the recommended healthy amount. Good sleep doesnt just boost our feelings of wellbeing. Theres a growing scientific consensus that it protects us against heart disease diabetes and obesity. In sleep labs participants who have their sleep cycles severely thrown off for just three weeks can start to appear http prediabetic on blood tests. If you doubt the importance of sleep consider this Scientists now believe that cycles of restfulness and alertness are core organizing principles of all life on Earth. Even the tiniest singlecell organisms contain the genetic coding httplearn.genetics.utah.educontentinheritanceclockgenes for a circadian rhythm. Of course there are many prescription sleep aids on the market unfortunately they arent very effective and can be addictive and dangerous. So many httpsnccih.nih.govresearchstatisticsNHISnaturalproductsmelatonin prefer to walk into a corner drug store and buy an alternative for just  thats marketed as safe and all natural. Its melatonin and unlike other chemicals http sold as nutrition supplements in America theres some scientific evidence to back up its claims. But like all sleep drugs melatonins story is complicated. Despite the fact its a chemical that our bodies naturally produce during sleep how melatonin actually works and what its best for is worth a good hard look. What is melatonin Melatonin was originally discovered in the s when a dermatology lab thought it played a role in skin pigmentation. The researchers all took a massive dose of their newfound chemical expecting their skin to lighten. But they just got sleepy. What scientists eventually realized about melatonin is this Its the hormone that tells the body when it is nighttime. Its made in the pineal gland a pineconeshaped structure located deep in the brain. In lower vertebrates like the frog the pineal is in fact a third eye  its a lightdark receptor Dick Wurtman a MIT cognitive scientist who help discover melatonins function in humans says. Scientists once assumed that it had served a function in mammals but had become a vestigial https organ bound to disappear in a few million years Wurtman says.  In this animation the pineal gland is highlighted in red. Life Science Databases  Wikimedia Commons  In the s Wurtman and his team at MIT found that light does still reach the pineal in mammals  through the eyes  and controls the release of melatonin. During the day melatonin is inhibited by light. At night it flows into the bloodstream  unless were around bright http light or blue light http which suppress the release of melatonin and keep us up. When it does reach the bloodstream melatonin acts as a messenger. How the body responds to the message depends on the animal. Rats for instance are nocturnal so melatonin may play a role in keeping them awake. In humans and other daydwelling creatures it prepares the body for rest and helps maintain that rest throughout the night. In humans melatonin is thought to promote sleep in two ways. . The exact pathway isnt well understood but its believed melatonin broadly suppresses the areas of the brain involved in wakefulness. Melatonin may also play http a role in lowering body temperature which is needed for sleep. . Melatonin helps set the overall pace of the master circadian clock in the body. Scientists have shown that when people are given httppress.endocrine.orgdoifull.jc. melatonin in the afternoon their body clocks can be tricked into thinking its later and they get sleepier sooner. This can be handy if youre suffering from jet lag and your body thinks its still in an earlier time zone. More on this later. So how well does melatonin work When assessing melatonin there are a couple of big questions researchers are asking  Does it help people with insomnia fall asleep faster   Does it help people stay asleep  Does it help people sleep in new time zones  Is it helpful for people adjusting to new shifts at work  And does it reliably shift a persons body clock to a new phase  The studies that have been done on these questions have tested a wide range of doses on many different populations which makes direct comparisons among studies very difficult and limits what we can really learn from them. But the meta analyses of melatonin that do exist does find some evidence that it can be helpful in regard to most of the above questions. Patty Deuster a research scientist at Uniformed Services University of the Health Sciences was the senior author on a  systematic review httpsnutritionj.biomedcentral.comarticles. on melatonin. She and her team amassed a total of  randomized placebocontrolled studies on healthy people with or without a diagnosis of insomnia. The effect of melatonin for insomnia was positive but weak says Deutster. More studies with greater number of participants are needed. Her review found weak positive findings for sleep onset staying asleep and jet lag. The evidence for shift workers and shifting the body clock were inconclusive. However the experts with whom I spoke said melatonin should be taken in the late afternoon to have the best chance at shifting the biological clock. Deusters report only looked at phaseshifting studies when melatonin is given at night. International health organizations have analyzed melatonin research as well. In Europe melatonin is only available by prescription in some countries. In  the European Food Safety Authority which regulates melatonin conducted an overview http_outputfilesmain_documents.pdf of the evidence on melatonin and concluded this Melatonin helps reduce the time to fall asleep. That might be true but not all researchers agree that melatonin can make a meaningful difference. Philip Gehrman a sleep researcher and clinician at the University of Pennsylvania says The research is pretty clear that melatonin is a lousy sleeping pill. A  meta review http looked at this question more closely analyzing  placebocontrolled studies of otherwise healthy people with insomnia. It found on average melatonin decreased the time it took to fall asleep compared to placebo by . minutes it increased the time spent asleep by . minutes and increased sleep efficiency a ratio of time spent lying bed versus time sleeping by . percent. Meanwhile a  metaanalysis http found that a type of prescription sleeping pill called benzodiazepines httpsen.wikipedia.orgwikiBenzodiazepine got people to sleep  minutes faster on average. Nonbenzodiazepines like Ambien get people to sleep about . minutes faster. And once youre asleep these drugs only increase the time spent asleep by  or so minutes. https Dont forget that these drugs can be addicting and can kill a person in high enough doses. Melatonin may work best for jet lag and in people who have low melatonin When a person is jet lagged their bodys clock is off from the clock of their destination. This can make it hard to sleep. Melatonin may be particularly helpful for jet laggers because it can both help change a persons internal clock to match local time and it can help them sleep after a long restless flight. In  the Cochrane Library conducted a systematic review of melatonins ability to help a person readjust to a new sleep schedule after jet lag at doses as small as . milligrams. Melatonin is remarkably effective in preventing or reducing jet lag and occasional shortterm use appears to be safe the review concluded httponlinelibrary.wiley.comdoi..CDabstract especially when used after eastward flights. Eight of the ten trials found that melatonin taken close to the target bedtime at the destination pm to midnight decreased jetlag from flights crossing five or more time zones. Melatonin also seems to work much better for certain individuals. If your sleep problem results from a deficiency of the hormone melatonin then melatonin will be very effective for your sleep problem Wurtman says. If sleep problems stem from anxiety for instance it will be less effective. Frank Scheer who studies chronobiology at Harvard agrees An oral dose of melatonin has the best chance to make someone sleepy when internal melatonin levels are low. In healthy subjects if you give subjects melatonin in the middle of the day it will help them sleep during the middle of the day he says. If I give melatonin to you during the night when melatonin levels are higher and youre healthy melatonin wont have any effect on sleep. Scheer also notes that melatonin doesnt follow a typical doseresponse curve. That means taking a higher dose of melatonin doesnt necessarily result in more sleepiness. People tend to produce less melatonin as they age so the hormone may be more suited httpweb.mit.edudick to treating the insomnia thats the result of aging. Melatonin also been shown to be much more effective for people with delayed sleep phase http a condition where a persons biological clock is permanently out of sync with the rest of the world. Are there side effects Deusters review looked at the reporting of adverse effects across all  studies and found nothing serious. The most commonly reported side effect was drowsiness which is kind of the point of taking melatonin and headache. But Scheer says there are some cases where melatonin can have adverse effects. For some people with a particular genetic variant melatonin impairs http the bodys ability to process blood glucose. Its not harmless he says. The risks of longterm use have also not been assessed. There are no clear studies beyond six months of duration on melatonins use Scheer says. When to take melatonin Researchers have never done a systematic review of whether the timing of melatonin matters for people who want to get to sleep faster. The ones I talked to also disagreed on when to take it  depending on whether they thought melatonin was better for sleep promotion or circadian clock resetting. According to Gehrman melatonins ability to shift the circadian clock is stronger than its ability to promote immediate sleep. Therefore instead of taking it at bed time you take it several hours before bedtime he says. This can advance the biological clock around a half hour every day. Scheer agrees that taking melatonin in the late afternoon or early evening will result in the largest phase advance meaning the next day your body clock will be slightly earlier. Exposure to sunlight in the morning helps too he says and may be even more effective than melatonin or should be used in addition to melatonin when pushing the clock forward. Wurtman however doesnt recommend taking melatonin several hours before bed. He says melatonins albeit weak ability to promote sleep on the spot means that people should take it shortly before bed. Overall Scheer says the ideal time for any individual to take it is hard to predict. Melatonin is not simple to use as a consumer he says adding that many primary care physicians may not know about its subtleties. Another reason for caution Melatonin isnt well regulated Voxs Julia Belluz has done extensive reporting http on the murky regulations of dietary supplements in America. Basically she finds the dietary supplement aisle is a minefield. Supplements dont always contain what they say they do and they can have harmful additives. Thats why its important make sure the brand of melatonin you buy has its contents verified by a third party like USP http According to Wurtman the fact that we treat melatonin as a dietary supplement is unmitigated bullshit. None of our bodies natural melatonin comes from diet. In the case of melatonin the lax regulations means it can be sold in massive completely unnecessary doses. At the drug store its easy to pick up a  milligram httpsgo.redirectingat.comidXxsurlhttpAFF per pill bottle of melatonin. But this is likely overkill. Many of the studies on melatonin find that it works just as well at small doses  around one milligram or less  as it does in high doses. Plus theres a chance a huge dose will desensitize your brain to the hormone. If you present to your brain blood levels of melatonin that are way way higher than any that occur normally you desensitize the brains receptors to melatonin Wurtman says. You become less and less and less responsive. The bottom line according to the experts Start with a small dose and see if it works for you. And finally Know that a pill may never fully combat the reasons why Americans are sleeping poorly. There are myriad ways the modern world conspires against good sleep Stress at home and work noisy neighborhoods spending too little time in bright daylight drinking too much caffeine working odd shifts not getting enough exercise spending too much time with smartphones late at night and the list goes on."