Melatonin improves sleep, & sleep is valuable
biology, psychology, nootropics
2008-12-192015-02-14 finished certainty: likely importance: 9

I dis­cuss mela­ton­in’s effects on sleep & its safety with re­search up to 2015; I segue into the gen­eral ben­e­fits of sleep and the se­verely dis­rupted sleep of the mod­ern West­ern world, the cost of mela­tonin use and the ben­e­fit (eg. en­forc­ing reg­u­lar bed­times), fol­lowed by a ba­sic cost-ben­e­fit analy­sis of mela­tonin con­clud­ing that the net profit is large enough to be worth giv­ing it a try bar­ring un­usual con­di­tions or very pes­simistic safety es­ti­mates.

One of the prob­lems with ‘pro­duc­tiv­ity’ gim­micks is as­sess­ing their worth. Many of them claim im­mea­sur­able gains1, du­bi­ous gains2, or clear gains which mayn’t be worth the over­head3. The ben­e­fits of oth­ers are per­fectly mea­sur­able, like adding for repet­i­tive tasks; just time the man­ual way ver­sus the short­cut, and mul­ti­ply it by the us­age. But then the cost is hard to mea­sure. How to as­sess the price of cre­at­ing, learn­ing, and ren­der­ing ha­bit­ual a cus­tom short­cut? There are scads of use­ful bind­ings in that I have tried to learn, only to for­get them or re­mem­ber them after I needed them. My fa­vorite ‘pro­duc­tiv­ity tool’ is one that suffers from none of these prob­lems, and has re­fresh­ingly clear-cut costs and ben­e­fits. Even though it eats up a third to a half of your life, sleep is ne­glected be­cause peo­ple as­sume it is too hard to quan­tify or is too mys­te­ri­ous; but since it takes such a large chunk of time, even doubt­ful or un­re­li­able im­prove­ments are well worth your while.


(Ex­am­ine.­com; FDA ad­verse events) is a se­creted by the . Its pri­mary pur­pose is reg­u­lat­ing the sleep cy­cle; its abate­ment per­mits wak­ing. Odds are your lo­cal green­gro­cer car­ries it. It’s often used by peo­ple suffer­ing from in­som­nia or to com­bat con­di­tions such as .4 It has other mis­cel­la­neous uses like com­bat­ing other chrono­bi­o­log­i­cal is­sues and linked prob­lems like de­pres­sion (it’s been claimed mela­tonin use may cause or ex­ac­er­bate de­pres­sion, but the re­search does­n’t seem to bear this out).

But it’s also use­ful for adults5 with per­fectly nor­mal sleep­-cy­cles6. I am un­sure whether its effect is to put one to sleep faster, or to do that and also deepen sleep, but mela­tonin does it well. The 2005 meta-analy­sis Brzezin­ski et al con­cluded that, over all (mostly healthy) adult par­tic­i­pants, mela­tonin im­proved on placebo to the ex­tent that it

[s­ta­tis­ti­cal­ly-]sig­nifi­cantly re­duced sleep on­set la­tency by 4.0 min (95% CI 2.5-5.4) [The nor­mal lim­its for la­tency to sleep are con­sid­ered to be 15-20 min.]; in­creased sleep effi­ciency by 2.2% (95% CI 0.2-4.2) [The nor­mal sleep effi­ciency is about 90-95%.], and in­creased to­tal sleep du­ra­tion by 12.8 min (95% CI 2.9-22.8). Since 15 of the 17 stud­ies en­rolled healthy sub­jects or peo­ple with no rel­e­vant med­ical con­di­tion other than in­som­nia, the analy­sis was also done in­clud­ing only these 15 stud­ies. The sleep on­set re­sults were changed to 3.9 min (95% CI 2.5-5.4); sleep effi­ciency in­creased to 3.1% (95% CI 0.7-5.5); sleep du­ra­tion in­creased to 13.7 min (95% CI 3.1-24.3).

The meta-analy­ses or re­views & Braam et al 2009 & Kee­gan et al 2013 & turn up weaker or sim­i­lar re­sults in other pop­u­la­tions, the last men­tion­ing (im­por­tantly for de­pen­dency con­cerns) that the sleep qual­ity ben­e­fits did not seem to be mod­er­ated by “trial du­ra­tion and mela­tonin dose.” The effects may be stronger in the old or el­derly7; per­haps due to their , and Braam et al 2009 in­ter­est­ingly spec­u­lates that effects of mela­tonin are un­der­stated due to most data com­ing from sub­jects sleep­ing in an alien sleep lab­o­ra­tory en­vi­ron­ment:

Vi­sual in­spec­tion of the stan­dard for­est plots, as pre­sented in the three meta-analy­ses in in­di­vid­u­als with­out in­tel­lec­tual dis­abil­i­ty, sug­gests that the change in sleep la­tency in stud­ies in which mea­sure­ments were per­formed in a sleep lab­o­ra­tory us­ing polysomnog­ra­phy is smaller com­pared with stud­ies that were per­formed un­der home con­di­tions. Re-an­a­lyz­ing the data pre­sented in these stud­ies shows that the mean change in sleep la­tency in the stud­ies us­ing polysomnog­ra­phy is 10.1 min­utes, whereas change in sleep la­tency in stud­ies per­formed un­der home con­di­tions is 16.8 min­utes. The in­clu­sion of a sub­stan­tial num­ber of stud­ies us­ing polysomnog­ra­phy in the meta-analy­ses in in­di­vid­u­als with­out in­tel­lec­tual dis­abil­ity may have con­tributed to the smaller de­crease in sleep la­tency com­pared with our meta-analy­sis, in which all stud­ies were per­formed un­der home con­di­tions.



Mela­tonin is ap­par­ently 8; from Wikipedia, a , and a re­view (re­spec­tive­ly) of mela­tonin stud­ies:

Mela­tonin ap­pears to cause very few side-effects in the short term, up to three months, when healthy peo­ple take it at low dos­es. A sys­tem­atic re­view[] in 2006 looked specifi­cally at effi­cacy and safety in two cat­e­gories of mela­tonin us­age: first, for sleep dis­tur­bances that are sec­ondary to other di­ag­noses and, sec­ond, for sleep dis­or­ders such as jet lag and shift work that ac­com­pany sleep re­stric­tion.[63] The study con­cluded that ‘There is no ev­i­dence that mela­tonin is effec­tive in treat­ing sec­ondary sleep dis­or­ders or sleep dis­or­ders ac­com­pa­ny­ing sleep re­stric­tion, such as jet lag and shift-work dis­or­der. There is ev­i­dence that mela­tonin is safe with short term use.’[63] A sim­i­lar analy­sis[] by the same team a year ear­lier on the effi­cacy and safety of ex­oge­nous mela­tonin in the man­age­ment of pri­mary sleep dis­or­ders found that: ‘There is ev­i­dence to sug­gest that mela­tonin is safe with short­-term use (3 months or less).’

The most com­monly re­ported ad­verse effects of mela­tonin were nau­sea (in­ci­dence: ~1.5%), headache (in­ci­dence: ~7.8%), dizzi­ness (in­ci­dence: 4.0%), and drowsi­ness (in­ci­dence: 20.33%); how­ev­er, these effects were not [s­ta­tis­ti­cal­ly-]sig­nifi­cant com­pared to place­bo. This re­sult did not change by dose, the pres­ence or ab­sence of a sleep dis­or­der, type of sleep dis­or­der, du­ra­tion of treat­ment, gen­der, age, for­mu­la­tion of mela­ton­in, use of con­cur­rent med­ica­tion, study de­sign, qual­ity score, and al­lo­ca­tion con­ceal­ment score.9

A 2010 trial tested a de­layed-re­lease mela­tonin over 6 months and found min­i­mal ad­verse effects and no tol­er­ance or “ad­dic­tion”, as well as ben­e­fits for both the young and old adults in the tri­al. A 2012 sur­vey of 101 Aus­tralian doc­tors pre­scrib­ing mela­tonin for chil­dren for as long as 4 years found lit­tle aware­ness of side-effects. Nat­ural Stan­dard 2011:

Based on avail­able stud­ies and clin­i­cal use, mela­tonin is gen­er­ally re­garded as safe in rec­om­mended doses (5 mil­ligrams dai­ly) for up to two years. Avail­able tri­als re­port that over­all ad­verse effects are not [s­ta­tis­ti­cal­ly-]sig­nifi­cantly more com­mon with mela­tonin than place­bo. How­ev­er, case re­ports raise con­cerns about risks of blood clot­ting ab­nor­mal­i­ties (par­tic­u­larly in pa­tients tak­ing war­far­in), in­creased risk of seizure, and dis­ori­en­ta­tion with over­dose.


The FDA does not reg­u­late mela­ton­in, as a sup­ple­ment, but it has de­clined to give it -s­ta­tus - the high­est level of safety which al­lows it to be added to reg­u­lar food; its warn­ing let­ters are good sources if we are look­ing for ev­i­dence against mela­ton­in’s safe­ty. One such let­ter, sent to the mak­ers of the soda which in­cludes mela­ton­in, cites 3 pieces of ev­i­dence:

  1. in­creased can­cer in fe­male lab mice (but an in­creased lifes­pan! And hu­man stud­ies have not found any in­creased can­cer10)
  2. reti­nal dam­age in 2 lab mice vari­ants (hu­man clin­i­cal study found a pro­tec­tive effect11)
  3. a sum­mary of a re­view mono­graph men­tion­ing hu­man re­search find­ing weak po­ten­tial for de­creased blood pres­sure12, hy­per­glycemia13, and in­creased ath­er­o­scle­rotic plaque, and its gen­eral con­cern about the use of a hor­mone


Health & performance

Luke: “Is the dark side stronger?”
Yoda: “No, no, no! Quick­er, eas­ier, more se­duc­tive…”14

One might ob­ject that they do not wish to tam­per with their nat­ural sleep, even if mela­tonin is a nor­mal­ly-se­creted hor­mone.

Sad to say, I would point out to such read­ers that they are al­ready pro­foundly tam­per­ing with their nat­ural sleep cy­cle, and in­deed, all of West­ern civ­i­liza­tion is tam­per­ing with it; most of my read­ers do not even sleep mul­ti­ple times dur­ing the day, as ‘Na­ture in­tends’ and as hu­mans have usu­ally slept through his­tory1516, but rather in a sin­gle 7-9 hour long block. causes neg­a­tive changes sim­i­lar to ag­ing, and , both acute and chronic, dam­age men­tal per­for­mance17, and chronic does so cu­mu­la­tively over the de­pri­va­tion pe­riod (con­verse­ly, sleep im­proves per­for­mance); worse, one may not be able to sim­ply sleep in on the week­end, both be­cause it’s too short a time pe­riod to re­pay sleep debt (De­ment 2005 not­ing it may take a full month to re­pay the large sleep debt in­curred by reg­u­lar short­falls; in well-rested mice can take to men­tally re­cover from) and be­cause in prac­tice one does­n’t sleep in very much - the Zeo data­base of sleep records only an ex­tra 23 min­utes a day on the week­end. Sub­jects in chronic sleep de­pri­va­tion stud­ies sub­ject to were sub­jec­tively un­able to no­tice their per­for­mance de­clines (NYT); and since “short sleep­ers” seem lit­tle differ­ent from every­one else, this sug­gests that many peo­ple who be­lieve they are short sleep­ers are just hurt­ing them­selves. Fi­nal­ly, there are mul­ti­ple lines of re­search sug­gest­ing chronic sleep de­pri­va­tion is preva­lent among young adults (in­clud­ing his­tor­i­cal com­par­isons[See Webb WB, Ag­new HW (1975), “Are we chron­i­cally sleep de­prived?” Bull. the Psy­cho­nomic Soc. 6:47-48.][“Never Enough Sleep: A Brief His­tory of Sleep Rec­om­men­da­tions for Chil­dren” re­views lit­er­a­ture from 2009 back to 1897, find­ing that sleep fell by around an hour on av­er­age (with very wide vari­a­tion at both dates); they also find that sleep rec­om­men­da­tions are reg­u­larly an­chored to­wards rec­om­mend­ing more sleep than chil­dren were ac­tu­ally get­ting - which the au­thors ap­par­ently take as ev­i­dence for the rec­om­men­da­tions be­ing false but I take as per­fectly con­sis­tent with the pic­ture I il­lus­trate here of an ever more short­-sleep­ing mod­ern so­ci­ety and ex­plic­a­ble by the fact that the av­er­age of the 1890s sleep rec­om­men­da­tions—10.8 hours—­would be hys­ter­i­cally laughed at by mod­ern par­ents (hence the av­er­age rec­om­men­da­tion in the 2000s of closer to 9.8 hours).]). It is strik­ing that un­em­ployed adults sleep a full hour longer than the em­ployed18, and that when nor­mal adults are placed in set­tings with­out ar­ti­fi­cial light like camp­ing or with­out any time in­di­ca­tors, they sleep longer than be­fore - ex­actly as if they were sleep de­prived.19 Ad­di­tional sleep is linked with ath­letic20 and artis­tic suc­cess21, that even a hour’s tam­per­ing with mela­tonin se­cre­tion leads to mea­sur­able per­for­mance changes, mela­tonin se­cre­tion de­clines markedly with age, and so on and so on. One could well ask with , “Why am I to feel this pain?”

One some­times sees peo­ple in­voke a sort of against mela­ton­in; from the WSJ:

As soon as our own son started ask­ing for the “magic” pill, my hus­band and I stopped giv­ing it to him. Two years lat­er, he still suffers from oc­ca­sional in­som­nia. But when­ever I get frus­trat­ed, I think back to what Dr. Ditchek told me. “For thou­sands of years our chil­dren have been falling asleep with­out the need for pills,” he said. “Giv­ing your healthy child a pill to fall sleep is send­ing him the wrong mes­sage - that he needs a pill to do what should come nat­u­ral­ly.”

How­ev­er, we are not in a nat­ural sit­u­a­tion, but a pro­foundly un­nat­ural one. For chil­dren in par­tic­u­lar, Ma­tric­ciani et al 2012 demon­strated a dras­tic fall in their sleep time over the past cen­tu­ry, in­di­cat­ing that they are not in any state of na­ture. (Or con­sider the dra­matic spike in my­opia in many coun­tries over the 20th cen­tu­ry, which is linked to lack of ex­po­sure to nor­mal bright light caus­ing in­suffi­cient oc­u­lar growth.) And aside from all the pre­vi­ous cited ev­i­dence that one’s sleep is al­ready be­ing heav­ily affected by mod­ern lifestyles (de­pri­va­tion, monopha­sic block sleep, etc), there’s a spe­cific ar­gu­ment to be made that the health of heavy elec­tron­ic­s-users (such as my­self and my read­ers) will im­prove through mela­tonin sup­ple­men­ta­tion: mod­ern ar­ti­fi­cial elec­tri­cal light­ing dur­ing the evening is sys­tem­at­i­cally tam­per­ing with sleep and mela­tonin se­cre­tion in par­tic­u­lar.

Com­puter use cor­re­lates with less sleep and neg­a­tive events in teenagers, who are forced into be­ing night-owls by pu­ber­ty; mela­tonin helps them sleep more nor­mal­ly. In­door light­ing affects the and or­di­nary room light­ing at night, be­fore bed­time, has been shown to im­prove alert­ness - but do­ing so by cut­ting mela­tonin se­cre­tion, by as much as half22 with com­puter tablets such as the iPad cut­ting it by a fifth in one ex­per­i­ment & sim­i­larly with mon­i­tors, and after­noon/evening ar­ti­fi­cial light dam­ages sub­jec­tive alert­ness & per­for­mance com­pared to nat­ural light23. Light affects mela­tonin se­cre­tion even when your eyes are shut. Blue light is the 24 (white is still bad, though). An ad­di­tional list of rel­e­vant stud­ies on light & mela­tonin & sleep is un­der f.lux’s sum­mary page NIH-Funded re­search”.

There are coun­ter-mea­sures to re­duce one’s ex­po­sure to blue light like light-fil­ter­ing glasses25 or pro­grams such as Red­shift/f.lux which lower the (re­duc­ing the blue­ness & in­creas­ing red­ness) of one’s mon­i­tor. They are a good idea26. (Peo­ple who, for var­i­ous rea­sons, aban­don elec­tri­cal light­ing re­mark on the si­mul­ta­ne­ous shifts in their sleep - I no­ticed this when watch­ing & _, and oc­ca­sion­ally run into anec­do­tal re­ports like J.D. Moyer.) But they aren’t per­fect so­lu­tions and only re­duce the dam­age; and if is right that fu­ture bright will be cheaper and more pop­u­lar, we can ex­pect that much more prob­lems with mela­tonin de­fi­cien­cy/­sup­pres­sion (Czeisler 2013). And what are those prob­lems?

have been linked to a great many health prob­lems (such as var­i­ous can­cers or men­tal de­lays; see ), and the pro­posed causal mech­a­nism is usu­ally a mela­tonin de­fi­ciency (and mela­tonin sup­ple­men­ta­tion one of the ). (They have also been linked to many ac­ci­dents and near-ac­ci­dents.)

An ad­di­tional ad­van­tage is the wide­ly-re­ported in­crease in dreams or vivid­ness of dreams; but some re­port this leads to in­creased night­mares as well, so this is not a ma­jor ar­gu­ment for us­ing mela­tonin sup­ple­ments.


My ba­sic ar­gu­ment is:

  • it works

If that’s not enough, an ex­tended ar­gu­ment goes:

  1. elec­tri­cal light­ing and elec­tri­cal de­vices in par­tic­u­lar emit blue light
  2. blue light in­hibits in­crease of mela­tonin lev­els
  3. mela­tonin sup­ple­men­ta­tion in­creases mela­tonin lev­els
  4. in­crease in mela­tonin lev­els is nec­es­sary to sleep well
  5. ei­ther elim­i­nat­ing elec­tric­ity or mela­tonin sup­ple­men­ta­tion will cause mela­tonin lev­els to rise
  6. one will not elim­i­nate elec­tric­ity
  7. one can use mela­tonin sup­ple­men­ta­tion
  8. it works

The ex­ist­ing phe­nom­e­non of alarm clocks etc is par­tially caused by this effect. Peo­ple live nor­mal mod­ern lives with count­less de­vices, and stay up too late or sleep poor­ly. To avoid one of the con­se­quences, over­sleep­ing, they use alarm clocks. Of course, ei­ther lack of mela­tonin or lack of suffi­cient sched­uled time can tor­pedo one’s over­all qual­i­ty. Mela­tonin is nec­es­sary, but not suffi­cient, as is suffi­cient hours in bed.

Tempus Fugit

My rule of thumb is mela­tonin sub­tracts an hour. (I orig­i­nally guessed at this val­ue, but my Zeo sleep record­ings seem to sug­gest the value is more like 50 min­utes.) That is: if one slept for 7 hours, one awakes as re­freshed as if one had slept for 8 hours etc. From com­par­ing with oth­ers, I think I ben­e­fit more than around two-thirds of peo­ple.

There are few to no side-effects to mela­tonin use in adults (there is un­cer­tainty about the risks & ben­e­fits in chil­dren & ado­les­cents27), and it is not ad­dic­tive or habit-form­ing like caffeine is. The usual dose for a night is 0.5-3 mg and I take 1.5mg28; my dose is highly likely to be too high. High doses may well be re­spon­si­ble for why some peo­ple try mela­tonin and re­port that it does noth­ing or hurts them, since in one study, the best dose for old peo­ple was 10x smaller (0.1mg or 0.3mg) and for one blind per­son, 0.5mg[“Low, but not high, doses of mela­tonin en­trained a free-run­ning blind per­son with a long cir­ca­dian pe­riod”, Lewy et al 2002][“En­train­ment of Free-Run­ning Cir­ca­dian Rhythms by Mela­tonin in Blind Peo­ple”]29. Zh­danova et al 1996 found 0.3mg & 1.0mg to affect sleep on­set sim­i­lar­ly. A study of de­layed-re­lease mela­tonin found with their high dose of 4mg (but not 0.4mg) el­e­vated mela­tonin lev­els 10 hours after bed­time (Goon­er­atne et al 2011) - po­ten­tially in­ter­fer­ing with wak­ing time. Forsling et al 1999 used doses of 0.05, 0.5 & 5.0mg, and mea­sured blood­-levels of var­i­ous hor­mones and chem­i­cals; 0.5 & 5.0mg were sim­i­lar ex­cept in in­hibit­ing & stim­u­lat­ing (re­spec­tive­ly) and . Tested sup­ple­ments have the claimed amounts of mela­ton­in, but their rec­om­mended doses can be ter­ri­ble ideas and defi­nitely should be ig­nored if they ad­vise more than 5mg!30 On­line anec­dotes fre­quently men­tion that doses of 0.5mg or less worked bet­ter than >1mg. (Ex­per­i­men­ta­tion may be nec­es­sary; peo­ple can be very differ­en­t.)

So that’s what it does: it lets one cut 1 hour of sleep. (There are other ben­e­fits, such as en­forc­ing a bed­time - in­valu­able for young peo­ple - but their val­ues are in­de­ter­mi­nate.)

Let’s work out the cost of reg­u­larly us­ing mela­tonin. Con­ser­v­a­tive­ly, a bot­tle of mela­tonin pills will cost about 6 USD for 150 pills. Per mil­ligram, the 3 mg pills are the least cost­ly, and are eas­ily con­vert­ible into lower dosages. Re­gard­less, one will get a min­i­mum of 150 doses per $6. 600⁄150 = 4¢ per pill. 1 night re­quires 1 dose, so each night costs 4¢. We need to con­sider how much we value the effort of re­mem­ber­ing and tak­ing the pill, though. Let us be con­ser­v­a­tive and price it as high as 10¢. So we spend 14¢ per night31. The re­ward is that we gain an hour.

Now how do we value an hour of our time? One could make an in­tu­itive guess, or con­sider one’s cur­rent salary and things like that, but in eco­nom­ics 101, it’s com­mon to just set the value of an hour at . This will hope­fully not be too er­ro­neous, since over our life­time, the days where that ex­tra hour was re­ally valu­able will bal­ance out the days where the hour was worth­less.

More con­crete­ly, the min­i­mum wage is the floor for one’s ; even if the hour’s op­por­tu­nity you forgo by sleep­ing more was­n’t worth a mil­lion dol­lars, you could still have worked a un­skilled min­i­mum wage job and got­ten the min­i­mum wage.32

The fed­eral min­i­mum wage as of 2008 is $6.55 an hour33. So let’s say that is the re­ward.


See also value of in­for­ma­tion cal­cu­la­tions for mela­tonin self­-ex­per­i­men­ta­tion.

In other words, by in­vest­ing 14¢, we re­al­ize a net of 655¢, for a profit of 641¢. This rep­re­sents a re­turn on our in­vest­ment of ap­prox­i­mately 4678% (). Sup­pose we use only half a pill a night? Then our num­ber of doses dou­bles, our pill price per night halves (though our 10¢ of effort re­mains con­stan­t), and our re­turn be­comes 5458% (). My lo­cal store some­times runs a 2-for-1 sale on mela­tonin. One could buy only at these sales - the low con­sump­tion rate (1 a night, or less) means you must buy less than an­nu­al­ly. Thus, the pill price halves again to 1¢ per night, and now the re­turn is 5959% ().

This as­sumes mela­tonin de­liv­ers its ben­e­fit with cer­tain­ty, or prob­a­bil­ity 1. Since, for ob­vi­ous rea­sons, there have been few stud­ies di­rectly study­ing how mela­tonin im­proves sleep in healthy adults, we are forced to es­ti­mate based on anec­dotes; as an ex­am­ple, we can look at >100 anec­dotes about mela­tonin us­age gen­er­ated in re­sponse to this es­say ad­vo­cat­ing mela­ton­in: 64 pos­i­tive/25 neg­a­tive/12 un­known, or 60% pos­i­tive. That the anec­dotes aren’t 100% pos­i­tive but only 60% sug­gests that the col­lec­tion is­n’t too badly skewed by var­i­ous se­lec­tion bi­as­es, since typ­i­cally the worry is that only the de­luded fans are post­ing about how sub­stance X trans­formed their life. By , our ex­pected nightly profit is still pos­i­tive: ¢.

Or one can rea­son in a “value of in­for­ma­tion” fash­ion: after us­ing the first jar of mela­ton­in, you will have a very good idea whether it makes you feel bet­ter and then you can ei­ther con­tinue or stop. If you have a 40% chance of los­ing the $10 that jar cost you and a 60% chance of profit­ing, say, a dol­lar a night for a year (let’s be con­ser­v­a­tive), we can eas­ily es­ti­mate the value of ex­per­i­ment­ing with that first jar: loss plus gain, or , or… $215. To put it an­other way, mela­tonin peo­ple ben­e­fit a lot from us­ing it and non-me­la­tonin peo­ple are out only the small cost of the ex­per­i­ment, so we would have to be very pes­simistic be­fore one quick ex­per­i­ment is not worth do­ing. And we have no rea­son to be >97% pes­simistic34.

Absolute gains

Let’s look at an­other per­spec­tive. Those are im­pres­sive per­cent­ages, but they’re on a low base so per­haps it’s not worth­while even with 6000% re­turns. What are the ab­solute gains one would re­al­ize over the course of a year? Well, to cal­cu­late: (), or to sim­pli­fy: () = $2350.60. We would have to as­sume our cal­cu­la­tions are 3 or 4 or­ders of mag­ni­tude off be­fore mela­tonin stops be­ing a good deal; the cheap­ness of use dom­i­nates the cal­cu­la­tion.

One year of mela­tonin am­ply re­pays the orig­i­nal costs of learn­ing about and ex­per­i­ment­ing with it. (And the long-run ben­e­fits are sub­stan­tial.35)


Speak­ing from per­sonal ex­pe­ri­ence, I know that one of the ob­sta­cles to sleep­ing well is go­ing to sleep at all. Even though one knows that one ought to go to bed on time, and that not do­ing so will cause prob­lems, it’s hard to ac­tu­ally do it. One wants to fin­ish the book, chat with friends, play a game, etc. It is even more diffi­cult when one does­n’t feel tired. For me, I had a chronic prob­lem with go­ing to sleep; in col­lege, it was bad enough that I would on oc­ca­sion stay up to 4 AM for no rea­son at all!

This dilemma is far from unique. It is called ; hu­mans can make the ra­tio­nal de­ci­sion when at a great dis­tance from a choice, but the closer they come, the more warped their de­ci­sions are. Pro­cras­ti­na­tion is often thanks to hy­per­bolic dis­count­ing - ‘hard work pays off to­mor­row but pro­cras­ti­na­tion pays off now’, and never mind that to­mor­row al­ways comes. Sim­i­lar­ly, ad­dicts want to be free of their ad­dic­tion, but their want for a drink right now over­whelms their life­time de­sire to not have drinks. (For more on the top­ic, see “Akrasia, hy­per­bolic dis­count­ing, and pi­coeco­nom­ics” and “Ap­plied Pi­coeco­nom­ics”.)

How do we deal with this? The clas­sic mech­a­nism is avoid­ing the choice en­tire­ly. An ad­dict can avoid bars or liquor stores, but no one can avoid sleep. Fail­ing to avoid the choice en­tire­ly, one raises the cost of ‘pro­cras­ti­na­tion’ - make the ad­dict pay $100 for every drink they take. Even ap­par­ently triv­ial cost in­creases like some­one watch­ing our com­puter desk­top through , or work­ing at a coffee shop36 can make a real differ­ence with pro­cras­ti­na­tion. We need to raise the cost, then, and some­how change the in­cen­tives to make us want to sleep.

We can do this sim­ply by wait­ing un­til the need to sleep is so strong we can no longer re­sist; and in prac­tice, many (e­spe­cially col­lege stu­dents) do just this. But few of us have the lux­ury of the bizarre sched­ule this en­tails. We could try some sort of mon­e­tary fine for not go­ing to bed by mid­night, but en­force­ment is diffi­cult and if you’re a col­lege stu­dent, you may not be able to afford a vow painful enough to de­ter you.

Mela­tonin al­lows us a differ­ent way of rais­ing the cost, a phys­i­o­log­i­cal & self­-en­forc­ing way. Half an hour be­fore we plan to go to sleep, we take a pill. The pro­cras­ti­nat­ing effect will not work - half an hour is so far away that our de­ci­sion-mak­ing process & willpower are undis­torted and can make the right de­ci­sion (viz. fol­low­ing the sched­ule). When the half-hour is up, the mela­tonin has be­gun to make us sleepy. Stay­ing awake ceases to be free, to be the de­fault op­tion; now it is costly to fight the mela­tonin and re­main awake. The choice of sleep may now pre­vail over the hy­per­bol­i­cal­ly-dis­torted choice of video games. The long time-lag and the ex­treme ease of tak­ing the mela­tonin makes it harder to suc­cumb to a kind of ‘meta-akra­sia37 where you come up with a good trick or so­lu­tion to make your­self do what­ever it is you need to do - and then you start pro­cras­ti­nat­ing/­suffer­ing from akra­sia about the trick!

And go­ing to sleep when you need to go to sleep is, in the long-run, a very valu­able thing in its own right.

Excuses, excuses…

Mela­tonin is a clear-cut Good Thing. The gains I have laid out are large enough I con­sider it ir­ra­tional for some­one not to use it, un­less:

  1. You’ve never heard of it, or seen an analy­sis of the pos­si­ble ben­e­fits.
    • You, dear read­er, are no longer al­lowed this ex­cuse.
  2. You are so poor that 6 dol­lars every 150 or 300 days is a crip­pling ex­pense.
    • But then how come you have the free time to read this?
  3. Mela­tonin sup­ple­ments just does­n’t work on you, pe­ri­od.
    • Pos­si­ble (I have read mul­ti­ple anec­dotes that mela­tonin did noth­ing to help), but it’s not that com­mon. Mela­tonin is­n’t some men­tal trick - it’s a fun­da­men­tal fact of mam­malian bi­ol­o­gy. I’ve run into more peo­ple who have tried mela­tonin and had it help than found it com­pletely in­effec­tive, and I won­der if some of the non-re­spon­ders var­ied their doses to test the lower ranges like 0.1mg.
  4. They work, but not well enough.
    • This im­plies that mela­tonin saves you only a few min­utes or sec­onds, else the gain would be smaller but still be pos­i­tive. (This too strikes me as un­like­ly.)
  5. You value a sim­pler, less com­pli­cated life that much.
    • Tak­ing a pill at night, and buy­ing some pills once every year or two stresses you out?
  6. You value an hour at less than 11¢, so mela­tonin is not profitable.
    • Please con­tact me. I would like to hire you at the princely rate of a quar­ter an hour to do drudge-work on Wikipedia.38
  7. You are a child or ado­les­cent (see the foot­note pre­vi­ous­ly)
    • Le­git­i­mate; at the very least, the cost-ben­e­fit analy­sis be­comes un­cer­tain enough that there’s no ob­vi­ous right an­swer.
  8. Mela­tonin is pre­scrip­tion-only or banned.
    • You have my sym­pa­thies.


A part­ing thought: mil­lions of Amer­i­cans (es­ti­mated at around a third or more of adults) reg­u­larly take sup­ple­ments. These sup­ple­ments are un­likely to help a bal­anced di­et, there is lit­tle ev­i­dence they do, and there are stud­ies which have in­di­cated ac­tual harm from the con­sump­tion of mul­ti­vi­t­a­mins39. Mul­ti­vi­t­a­mins are no­tice­ably more ex­pen­sive than mela­tonin pills, and are cer­tainly harder to swal­low. And this is to say noth­ing of sup­ple­ments which are ac­tu­ally dan­ger­ous, like . Do you take a mul­ti­vi­t­a­m­in, but not mela­ton­in? If so, how can you jus­tify this?

See Also

  • - if you want to go even fur­ther down the sleep­-mod­i­fi­ca­tion rab­bit hole of trad­ing money for time



Low mela­tonin lev­els and chrono­bi­o­log­i­cal dis­tur­bances have been fre­quently cor­re­lated with var­i­ous forms of de­pres­sion; eg.

  • Mendlewicz et al 1979 (re­view of ex­ist­ing re­search link­ing de­pres­sion with ab­nor­mal mela­tonin se­cre­tion & low lev­els)

  • Claus­trat et al 1984

  • Nair et al 1984

  • Brown et al 1985 & Frazer et al 1986 (2 stud­ies: de­pressed sub­jects had re­duced mela­tonin se­cre­tion. Fraz­er’s ab­stract notes that “These re­sults are sim­i­lar to those found re­cently by sev­eral other groups of in­ves­ti­ga­tors.” In­deed.)

  • Kennedy et al 1989 (con­trols vs eat­ing dis­or­der vic­tims; only eat­ing dis­or­der plus de­pres­sion cor­re­lated with lower mela­ton­in)

  • (“Post hoc analy­sis showed a [s­ta­tis­ti­cal­ly-]sig­nifi­cantly higher mela­tonin pro­file in de­pressed sub­jects with­out psy­chosis (n = 15) than in de­pressed sub­jects with psy­chosis (n = 7) or in the con­trols.”)

  • Voder­holzer et al 1997 (a neg­a­tive re­sult - study­ing 9 young de­pressed for­mer al­co­holics, Voder­holzer did not find any mela­tonin differ­ences)

  • Cras­son et al 2004 (found de­layed mela­tonin se­cre­tion eg. less in evening & more in morn­ing, but still sim­i­lar to­tal se­cre­tions)

  • Dal­laspezia & Benedetti 2011:

    Al­ter­ation of the sleep­-wake cy­cle and of the sleep struc­ture are core symp­toms of a ma­jor de­pres­sive episode, and oc­cur both in course of bipo­lar dis­or­der and of ma­jor de­pres­sive dis­or­der. Many other cir­ca­dian rhythms, such as the daily pro­files of body tem­per­a­ture, cor­ti­sol, thy­rotropin, pro­lact­in, growth hor­mone, mela­tonin and ex­cre­tion of var­i­ous metabo­lites in the urine, are dis­rupted in de­pressed pa­tients, both unipo­lar and bipo­lar in­di­vid­u­als. These dis­rupted rhythms seem to re­turn to nor­mal­ity with pa­tient re­cov­ery. Re­search on cir­ca­dian rhythms and sleep have led to the de­fi­n­i­tion of non­phar­ma­co­log­i­cal ther­a­pies of mood dis­or­der that can be used in every­day prac­tice…

  • Bedrosian et al 2012 (Si­ber­ian ham­sters acted de­pressed when sleep was dis­turbed by dim light)

Im­prove­ment or lack of harm:

  • Fainstein et al 1997

  • Jean-Louis et al 1998

  • Lewy et al 1998 -(­place­bo-con­trolled trial of 5 pa­tients)

  • (sleep im­prove­ments in the de­pressed; sta­tis­ti­cal­ly-sig­nifi­cant de­pres­sion im­prove­ment also oc­curred (pg4), but au­thors don’t re­gard the effect size as large enough to be im­por­tant. No men­tion of wors­en­ing.)

  • Bel­li­panni et al 2001 (they note in pass­ing, in a study of mela­ton­in’s effects on hor­mones in wom­en, that morn­ing mood im­proved in the treat­ed)

  • Pac­chierotti et al 2001 (re­view of pre­vi­ous tri­als; con­cluded the re­la­tion­ship be­tween mela­tonin & mood is un­clear and the ev­i­dence was not solid enough to out­right rec­om­mend it)

  • Danilenko & Putilov 2005 (effect of to­tal sleep de­pri­va­tion treat­ment fol­lowed by mela­tonin sup­ple­men­ta­tion on de­pres­sives; no change in mood due to the mela­ton­in)

  • Lewy et al 2006; 81 sub­jects; small im­prove­ments in de­pres­sion, al­though not de­signed to test that. The re­sults are very in­ter­est­ing inas­much as it sug­gests SAD is made of two pop­u­la­tions whose cir­ca­dian rhythm are differ­ently out of sync and who the the­ory pre­dicts would ben­e­fit from mela­tonin sup­ple­men­ta­tion at differ­ent times of day; the au­thors note that the sub­ject whose de­pres­sion got worse was also re­ceiv­ing mela­tonin at the ‘wrong’ time of day.

  • Garzón et al 2009 (sleep im­prove­ments in the el­derly us­ing mela­ton­in; ab­stract men­tions im­prove­ments in de­pres­sion ques­tion­naire scores but not whether any had ac­tu­ally been di­ag­nosed de­pressed)

  • Bright , which affects mela­ton­in, has been em­ployed with var­i­ous de­pres­sions:

  • Ser­faty et al 2010; sleep im­prove­ment with 6mg dos­es, with non-s­ta­tis­ti­cal­ly-sig­nifi­cant im­prove­ment in the de­pressed sub­jects’ mood.

  • Fava et al 2012: mela­ton­in+bus­pirone im­proved de­pres­sion scores more than bus­pirone or placebo

  • Del Fab­bro et al 2013

  • Hansen et al 2014 meta-an­a­lyzes mela­tonin for de­pres­sion, find­ing only weak ev­i­dence for ben­e­fits but also no ev­i­dence of harm.

Be­cause of mela­ton­in’s safety but weak an­ti-de­pres­sant effects, at­tempts have been made to im­prove on it. The best cov­ered seems to be which binds to mela­tonin re­cep­tors and in the clin­i­cal tri­als, has the de­sired an­ti-de­pres­sant effects. Hickie & Rogers 2011 re­views “the as­so­ci­a­tions be­tween dis­rupted chrono­bi­ol­ogy and ma­jor de­pres­sion” and re­gards agome­la­tine fa­vor­ably, as does Quera Salva et al 2011; al­though How­land 2011 re­viewed 13 place­bo-con­trolled tri­als of agome­latine, con­clud­ing that the ben­e­fit may not be large (but nei­ther men­tions agome­la­tine be­ing pro-de­pres­sant)

The one study I was able to find show­ing any neg­a­tive effects was Car­man et al 1976, a dou­ble-blind study of 6 de­pressed pa­tients; mela­tonin was ad­min­is­tered at var­i­ous times dur­ing the day at daily doses be­tween 250-1600mg (>83x the typ­i­cal doses for sleep­ing!) It does not seem to have been repli­cat­ed. Lewy et al 2006 would seem to sug­gest that if there is any­thing to it, the re­sults may be caused by the spe­cific tim­ing of mela­tonin sup­ple­men­ta­tion; Ser­faty et al 2010 sim­ply calls it “a method­olog­i­cally un­sound trial”. If noth­ing else, mela­tonin may help with the de­pressed’s sleep qual­ity (Dol­berg et al 1998, Dal­ton 2000, Garzón et al 2009).

  1. ↩︎

  2. ‘im­age-stream­ing’↩︎

  3. sched­ulers, , ↩︎

  4. For which it has a good sci­en­tific track record; eg Rikkert & Rigaud 2001, Zh­danova 2001, , Herx­heimer & Petrie 2002 or Buscemi et al 2004; this is the only use of mela­tonin Nat­ural Stan­dard gave an A rat­ing, ‘Strong sci­en­tific ev­i­dence for this use’.↩︎

  5. Ab­nor­mal chil­dren ben­e­fit, al­though this may be as much due to the fact that chil­dren usu­ally sleep very well to be­gin with and who would bother to study them? The Nat­ural Stan­dard:

    There are mul­ti­ple tri­als in­ves­ti­gat­ing mela­tonin use in chil­dren with var­i­ous neu­ro-psy­chi­atric dis­or­ders, in­clud­ing men­tal re­tar­da­tion, autism, psy­chi­atric dis­or­ders, vi­sual im­pair­ment, or epilep­sy. Stud­ies have demon­strated re­duced time to fall asleep (sleep la­ten­cy) and in­creased sleep du­ra­tion. Well-de­signed con­trolled tri­als in se­lect pa­tient pop­u­la­tions are needed be­fore a stronger or more spe­cific rec­om­men­da­tion can be made…Based on hu­man study, mela­tonin may be ben­e­fi­cial in chil­dren with in­som­nia. More well-de­signed stud­ies are needed be­fore a con­clu­sion can be made.

  6. Nat­ural Stan­dard 2011:

    Mul­ti­ple hu­man stud­ies have mea­sured the effects of mela­tonin sup­ple­ments on sleep in healthy in­di­vid­u­als. A wide range of doses has been used often taken by mouth 30 to 60 min­utes prior to sleep time. Most tri­als have been small, brief in du­ra­tion, and have not been rig­or­ously de­signed or re­port­ed. How­ev­er, the weight of sci­en­tific ev­i­dence does sug­gest that mela­tonin de­creases the time it takes to fall asleep (“sleep la­tency”), in­creases the feel­ing of “sleepi­ness”, and may in­crease the du­ra­tion of sleep. Bet­ter re­search is needed in this area.

  7. “Treat­ment effi­cacy of ex­oge­nous mela­tonin for in­som­nia in older adults: a meta-analy­sis”, Brault et al 2012; but it seems to have only been pub­lished as a poster/ab­stract, with a few more de­tails in me­dia cov­er­age.↩︎

  8. As one would ex­pect if the null hy­poth­e­sis re­ally is true, there are oc­ca­sional cases where mela­tonin has fewer side-effects than place­bo. found that slow-re­lease mela­tonin im­proved sleep qual­ity & la­ten­cy, but also that “The rate of ad­verse events nor­mal­ized per 100 pa­tien­t-weeks was lower for PRM [me­la­ton­in] (3.66) than for placebo (8.53).”↩︎

  9. “Mela­tonin for Treat­ment of Sleep Dis­or­ders: Sum­mary”; this meta-analy­sis also sug­gests that mela­tonin works on some met­rics, but has lit­tle or no effect on other mea­sure­ments, which is a con­trast to my own gen­er­ally san­guine be­lief.↩︎

  10. Nat­ural Stan­dard 2011:

    There are sev­eral ear­ly-phase and con­trolled hu­man tri­als of mela­tonin in pa­tients with var­i­ous ad­vanced stage ma­lig­nan­cies, in­clud­ing brain, breast, col­orec­tal, gas­tric, liv­er, lung, pan­cre­at­ic, and tes­tic­u­lar can­cer, as well as lym­phoma, melanoma, re­nal cell car­ci­no­ma, and soft­-tis­sue sar­co­ma. Cur­rent­ly, no clear con­clu­sion can be drawn in this area. There is not enough de­fin­i­tive sci­en­tific ev­i­dence to dis­cern if mela­tonin is ben­e­fi­cial against any type of can­cer, whether it in­creases (or de­creas­es) the effec­tive­ness of other can­cer ther­a­pies, or if it safely re­duces chemother­apy side effects.

  11. From the 2011 Nat­ural Stan­dard ‘Bot­tom Line Mono­graph’, ‘Ev­i­dence’ sec­tion:

    Mela­tonin may ex­ert an­tiox­i­dant effects which may con­tribute to its ben­e­fi­cial effects on the eyes. Ac­cord­ing to clin­i­cal study, mela­tonin may play a role in pro­tect­ing the retina to de­lay mac­u­lar de­gen­er­a­tion. Well-de­signed clin­i­cal tri­als are needed be­fore a con­clu­sion can be made….It has been the­o­rized that high doses of mela­tonin may in­crease in­traoc­u­lar pres­sure and the risk of glau­co­ma, age-re­lated mac­u­lopa­thy and my­opia, or reti­nal dam­age. How­ev­er, there is pre­lim­i­nary ev­i­dence that mela­tonin may ac­tu­ally de­crease in­traoc­u­lar pres­sure in the eye and de­lay mac­u­lar de­gen­er­a­tion, and it has been sug­gested as a pos­si­ble ther­apy for glau­co­ma. Ad­di­tional study is nec­es­sary in this area. Pa­tients with glau­coma tak­ing mela­tonin should be mon­i­tored by a health­care pro­fes­sion­al.

  12. NS 2011:

    Sev­eral con­trolled stud­ies in pa­tients with high blood pres­sure re­port small re­duc­tions blood pres­sure when tak­ing mela­tonin by mouth (o­ral­ly) or in­haled through the nose (in­tranasal­ly). Specifi­cal­ly, noc­tur­nal high blood pres­sure may im­prove with mela­tonin use. Bet­ter-de­signed re­search is nec­es­sary be­fore a firm con­clu­sion can be reached.

  13. NS 2011:

    El­e­vated blood sugar lev­els (hy­per­glycemia) have been re­ported in pa­tients with type 1 di­a­betes (in­sulin-de­pen­dent di­a­betes), and low doses of mela­tonin have re­duced glu­cose tol­er­ance and in­sulin sen­si­tiv­i­ty. Cau­tion is ad­vised in pa­tients with di­a­betes or hy­po­glycemia, and in those tak­ing drugs, herbs, or sup­ple­ments that affect blood sug­ar. Serum glu­cose lev­els may need to be mon­i­tored by a health­care provider, and med­ica­tion ad­just­ments may be nec­es­sary.

  14. The Em­pire Strikes Back↩︎

  15. Bi­modal or was uni­ver­sal un­til re­cent­ly, es­pe­cially in Eng­land; see A. Roger Ekirch’s “Sleep We Have Lost: Pre-in­dus­trial Slum­ber in the British Isles” and his 2005 At Day’s Close: Night in Times Past. An­thro­pol­ogy agrees; bipha­sic sleep is pos­i­tively pedes­trian↩︎

  16. from book on (Why We Nap pg 8–9):

    It is worth men­tion­ing that an­thro­po­log­i­cal stud­ies con­ducted in tribes ac­tive at night show that hu­man sleep can be highly polypha­sic in cer­tain cul­tures. Al­though they have differ­ent cul­tures and ways of life, both the Temi­ars of In­done­sia and the Ibans of Sarawak have sim­i­lar polypha­sic sleep­-wake be­hav­iors (Pe­tre-Quadens, 1983). Their av­er­age noc­tur­nal sleep episode du­ra­tion ranges be­tween 4 and 6 hr, and night­time ac­tiv­i­ties (fish­ing, cook­ing, watch­ing over the fire, rit­u­als) at any one time in­volve ap­prox­i­mately 25% of the adult mem­bers. Day­time nap­ping is very com­mon in both tribes: at al­most any time of day, about 10% of the adult mem­bers are asleep. What­ever the cause of these polypha­sic sleep pat­tern­s,whether the ex­pres­sion of an in­born ul­tra­dian rest-ac­tiv­ity ten­dency or other fac­tors, such pop­u­la­tions ex­hibit ex­tremely flex­i­ble and frag­men­tary sleep­-wake cy­cles. The min­i­mal con­tact with mod­ern civ­i­liza­tion could be one of the rea­sons for the preser­va­tion of this pos­si­bly an­ces­tral sleep pat­tern.

  17. With po­ten­tially fa­tal effect. From Coren 1998:

    In fact, our so­ci­etal sleep debt is so great that sim­ply los­ing one ad­di­tional hour of sleep due to the spring shift to day­light sav­ings time can in­crease traffic ac­ci­dent rates by 7% (Coren, 1996b) and death rates due to all ac­ci­dents by 6.5% (Coren, 1996c).

  18. “A com­ing study by Mr. Krueger, us­ing his­tor­i­cal data on time use be­tween 1991 and 2006, finds that un­em­ployed Amer­i­cans tend to sleep an hour longer than the em­ployed.” “Leisure Trumps Learn­ing in Time-Use Sur­vey: Amer­i­cans Opt for TV in Spare Hours, Not Work­outs or Class­es, Poll Finds”, 2011-06-23 Wall Street Jour­nal↩︎

  19. “Sleep De­pri­va­tion, Psy­chosis and Men­tal Effi­ciency”, Coren 1998, Psy­chi­atric Times

    Con­fir­ma­tion of these nat­ural sleep du­ra­tions comes from Palinkas et al 1995. These re­searchers spent a sum­mer above the arc­tic cir­cle where there is con­tin­u­ous light 24 hours a day. All watch­es, clocks and other time­keep­ing de­vices were re­moved, and only the sta­tion’s com­put­ers tracked the times that the team went to sleep and awak­ened. In­di­vid­ual re­searchers did their work, and chose when to sleep or wake ac­cord­ing to their “body time.” At the end of the ex­per­i­ment, they found that their over­all av­er­age sleep daily time was 10.3 hours. Every mem­ber of the team showed an in­crease in sleep time, with the short­est log­ging in at 8.8 hours a day, and the longest al­most 12 hours a day. This study, like many oth­ers, seems to sug­gest that our bi­o­log­i­cal need for sleep might be closer to the 10 hours per day that is typ­i­cal of mon­keys and apes liv­ing in the wild, than the 7 to 7.5 hours typ­i­cal of hu­mans in to­day’s high­-tech, clock­-driven lifestyle.

    On the other hand, Antarc­tica “has a rep­u­ta­tion for pro­vid­ing the worst qual­ity of sleep on Planet Earth” dur­ing the win­ter (in this case, par­tially due to al­ti­tude).↩︎

  20. “Peak Per­for­mance: Why Records Fall”, Gole­man 1994, The New York Times:

    “When we train Olympic weight lifters, we find we often have to throt­tle back the to­tal time they work out,” said Dr. Ma­honey. “Oth­er­wise you find a tremen­dous drop in mood, and a jump in ir­ri­tabil­i­ty, fa­tigue and ap­a­thy.”

    Be­cause their in­tense prac­tice reg­i­men puts them at risk for burnout or strain in­juries, most elite com­peti­tors also make rest part of their train­ing rou­tine, sleep­ing a full eight hours and often nap­ping a half-hour a day, Dr. Er­ic­s­son found.

  21. 1993:

    The high rel­e­vance of sleep for im­prov­ing vi­o­lin per­for­mance must be in­di­rect and re­lated to the need to re­cover from effort­ful ac­tiv­i­ties such as prac­tice. Con­sis­tent with the rat­ings, sleep is the least effort­ful of the ac­tiv­i­ties and thus con­sti­tutes the purest form of rest. The weekly amount of sleep dur­ing the di­ary week did not differ for the two best groups and av­er­aged 60.0 hr. This av­er­age was re­li­ably longer than that for the mu­sic teach­ers, which was 54.6 hr, jF(l, 27) = 5.02, p < .05. Hence the two best groups, who prac­tice more, also sleep re­li­ably longer.

  22. See “Light Ex­po­sure May Cut Pro­duc­tion of Mela­ton­in: Study Shows Ar­ti­fi­cial Light Be­fore Bed­time May Affect Qual­ity of Sleep”, WebMD; “Mela­tonin pro­duc­tion falls if the lights are on”, BBC News; and an older study, “The dark side of light at night: phys­i­o­log­i­cal, epi­demi­o­log­i­cal, and eco­log­i­cal con­se­quences”. More re­cent­ly, the re­leased its 2011 sur­vey find­ing ever more elec­tron­ics use be­fore bed; rel­e­vant quote:

    “Ar­ti­fi­cial light ex­po­sure be­tween dusk and the time we go to bed at night sup­presses re­lease of the sleep­-pro­mot­ing hor­mone mela­ton­in, en­hances alert­ness and shifts cir­ca­dian rhythms to a later hour–­mak­ing it more diffi­cult to fall asleep,” says Charles Czeisler, Ph.D., MD, Har­vard Med­ical School and Brigham and Wom­en’s Hos­pi­tal. “This study re­veals that light-emit­ting screens are in heavy use within the piv­otal hour be­fore sleep. In­va­sion of such alert­ing tech­nolo­gies into the bed­room may con­tribute to the high pro­por­tion of re­spon­dents who re­ported that they rou­tinely get less sleep than they need.” Com­puter or lap­top use is also com­mon. Roughly six in ten (61%) say they use their lap­tops or com­put­ers at least a few nights a week within the hour be­fore bed. More than half of gen­er­a­tion Z’ers (55%) and slightly less of gen­er­a­tion Y’ers (47%) say they surf the In­ter­net every night or al­most every night within the hour be­fore sleep.

  23. “Effects of prior light ex­po­sure on early evening per­for­mance, sub­jec­tive sleepi­ness, and hor­monal se­cre­tion”, Münch et al 2011 (me­dia cov­er­age):

    We tested the im­pact of two re­al­is­tic office light­ing con­di­tions dur­ing the after­noon on sub­jec­tive sleepi­ness, hor­monal se­cre­tion, and cog­ni­tive per­for­mance in the early evening hours. Twen­ty-nine young sub­jects came twice and spent 8 h (12:00-20:00) in our lab­o­ra­to­ry, where they were ex­posed for 6 h to ei­ther ar­ti­fi­cial light (AL) or to mainly day­light (DL). In the early evening, we as­sessed their sali­vary cor­ti­sol and mela­tonin se­cre­tion, sub­jec­tive sleepi­ness, and cog­ni­tive per­for­mance (n-back test) un­der dim light con­di­tions. Sub­jects felt [s­ta­tis­ti­cal­ly-]sig­nifi­cantly more alert at the be­gin­ning of the evening after the DL con­di­tion, and they be­came sleepier at the end of the evening after the AL con­di­tion. For cog­ni­tive per­for­mance we found a [s­ta­tis­ti­cal­ly-]sig­nifi­cant in­ter­ac­tion be­tween light con­di­tions, men­tal load (2- or 3-back task) and the or­der of light ad­min­is­tra­tion. On their first evening, sub­jects per­formed with sim­i­lar ac­cu­racy after both light con­di­tions, but on their sec­ond evening, sub­jects per­formed [s­ta­tis­ti­cal­ly-]sig­nifi­cantly more ac­cu­rately after the DL in both n-back ver­sions and com­mit­ted fewer false alarms in the 2-back task com­pared to the AL group. Lower sleepi­ness in the evening was [s­ta­tis­ti­cal­ly-]sig­nifi­cantly cor­re­lated with bet­ter cog­ni­tive per­for­mance (p<.05).

  24. To quote ex­ten­sively from “In Eyes, a Clock Cal­i­brated by Wave­lengths of Light”, New York Times:

    So sci­en­tists at the Uni­ver­sity of Basel in Switzer­land tried a sim­ple ex­per­i­ment: They asked 13 men to sit be­fore a com­puter each evening for two weeks be­fore go­ing to bed. Dur­ing one week, for five hours every night, the vol­un­teers sat be­fore an old-style flu­o­res­cent mon­i­tor emit­ting light com­posed of sev­eral col­ors from the vis­i­ble spec­trum, though very lit­tle blue. An­other week, the men sat at screens back­lighted by light-emit­ting diodes, or LEDs. This screen was twice as blue.

    “To our sur­prise, we saw huge differ­ences,” said Chris­t­ian Ca­jochen, who heads the Cen­ter for Chrono­bi­ol­ogy at the Uni­ver­sity of Basel. Mela­tonin lev­els in vol­un­teers watch­ing the LED screens took longer to rise at night, com­pared with when the par­tic­i­pants were watch­ing the flu­o­res­cent screens, and the deficit per­sisted through­out the evening. The sub­jects also scored higher on tests of mem­ory and cog­ni­tion after ex­po­sure to blue light, Dr. Ca­jochen and his team re­ported in the May is­sue of The Jour­nal of Ap­plied Phys­i­ol­o­gy. While men were able to re­call pairs of words flashed across the flu­o­res­cent screen about half the time, some scores rose to al­most 70% when they stared at the LED mon­i­tors.

    The find­ing adds to a se­ries of oth­ers sug­gest­ing, though cer­tainly not prov­ing, that ex­po­sure to blue light may keep us more awake and alert, partly by sup­press­ing pro­duc­tion of mela­tonin. An LED screen bright enough and big enough “could be giv­ing you an alert stim­u­lus at a time that will frus­trate your body’s abil­ity to go to sleep lat­er,” said Dr. Brainard. “When you turn it off, it does­n’t mean that in­stantly the alert­ing effects go away. There’s an un­der­ly­ing bi­ol­ogy that’s stim­u­lat­ed.”

    …Ar­ti­fi­cial light has been around for more than 120 years. But the light emit­ted by older sources, like in­can­des­cent bulbs, con­tains more red wave­lengths. The prob­lem now, Dr. Brainard and other re­searchers fear, is that our world is in­creas­ingly il­lu­mi­nated in blue. By one es­ti­mate, 1.6 bil­lion new com­put­ers, tele­vi­sions and cell­phones were sold last year alone, and in­can­des­cent lights are be­ing re­placed by more en­er­gy-effi­cient, and often bluer, bulbs.

    In Jan­u­ary in the jour­nal PLoS One, the Uni­ver­sity of Basel team also com­pared the effects of in­can­des­cent bulbs to flu­o­res­cents mod­i­fied to emit more blue light. Men ex­posed to the flu­o­res­cent lights pro­duced 40% less mela­tonin than when they were ex­posed to in­can­des­cent bulbs, and they re­ported feel­ing more awake an hour after the lights went off. In ad­di­tion, the quan­tity of light nec­es­sary to affect mela­tonin may be much smaller than once thought. In re­search pub­lished in March in The Jour­nal of Clin­i­cal En­docrinol­ogy and Me­tab­o­lism, a team at the Har­vard Med­ical School re­ported that or­di­nary in­door light­ing be­fore bed­time sup­pressed mela­tonin in the brain, even de­lay­ing pro­duc­tion of the hor­mone for 90 min­utes after the lights were off, com­pared with peo­ple ex­posed to only dim light.

    What do these find­ings mean to every­day life? Some ex­perts be­lieve that any kind of light too late into the evening could have broad health effects, in­de­pen­dent of any effect on sleep. For ex­am­ple, a re­port pub­lished last year in the jour­nal PNAS found that mice ex­posed to light at night gained more weight than those housed in nor­mal light, even though both groups con­sumed the same num­ber of calo­ries. Light at night has been ex­am­ined as a con­trib­u­tor to breast can­cer for two decades. While there is still no con­sen­sus, enough lab­o­ra­tory and epi­demi­o­log­i­cal stud­ies have sup­ported the idea that in 2007, the World Health Or­ga­ni­za­tion de­clared shift work a prob­a­ble car­cino­gen. Body clock dis­rup­tions “can al­ter sleep­-ac­tiv­ity pat­terns, sup­press mela­tonin pro­duc­tion and dis­reg­u­late genes in­volved in tu­mor de­vel­op­ment,” the agency con­clud­ed.

    See also a Navy-funded RPI sleep study, which found “Only the higher level of blue light re­sulted in a re­duc­tion in mela­tonin lev­els rel­a­tive to the other light­ing con­di­tions.”, or a an­i­mal study find­ing that blue light at night in­duced more de­pres­sive symp­toms than did red light (Bedrosian et al 2013).↩︎

  25. A fel­low user, San­jiv Shah has re­port­edly found large ben­e­fits for him­self from the or­ange glass­es, al­though he seems to not have a web­page on it but given talks; from Tech­nol­ogy Re­view, “The Mea­sured Life”:

    San­jiv Shah, a long­time in­som­niac who par­tic­i­pates in the Boston group, be­lieves that wear­ing or­ange-t­inted glasses for sev­eral hours be­fore bed makes it eas­ier for him to fall asleep. (The the­ory is that the or­ange tint blocks blue light, which has been shown in both hu­man and an­i­mal stud­ies to in­flu­ence cir­ca­dian rhythm­s.) To quan­tify the effects, he used not only the Zeo but also a thum­b-size de­vice called the Fit­bit, which in­cor­po­rates an ac­celerom­e­ter that mea­sures move­ment, and a cam­era trained on his bed to record his sleep for a month. His re­sults: with­out the glass­es, he took an av­er­age of 28 min­utes to fall asleep, but with them he took only four.

  26. Fel­low pro­gram­mers: you would par­tic­u­larly ben­e­fit from us­ing Red­shift/F.lux. If you don’t be­lieve my anec­dote, read some tes­ti­mo­ni­als.↩︎

  27. My own ex­pe­ri­ence was pos­i­tive, and teenagers are fre­quently sleep­-de­prived due to fac­tors like their cir­ca­dian rhythms wildly con­flict­ing with school sched­ules (see my rough notes on the top­ic). How­ev­er, chil­dren & ado­les­cents have mela­tonin se­cre­tion rates 5-9 times greater than mid­dle-aged or very old adults, and those very high rates com­bined with large sup­ple­ments like 3mg may (and I use this word ad­vis­ed­ly) be able to push mela­tonin con­cen­tra­tion to high enough lev­els that some neg­a­tive chem­istry may hap­pen (ex­tremely high doses have often been used in clin­i­cal tri­als with no noted side-effect eg. 40mg/­day but these are al­most all adult­s). In ad­di­tion, there’s gen­eral un­cer­tainty about how mela­tonin in­ter­acts with pu­berty and why the con­cen­tra­tion falls so much with age.↩︎

  28. Mela­tonin has been played with in ex­tremely high doses for pur­poses other than sleep mod­i­fi­ca­tion; for ex­am­ple, at <20mg it may help with ther­mal in­jury, and at 75mg and higher (doses up to 200mg are men­tioned), it’s a fe­male con­tra­cep­tive. My per­sonal ex­pe­ri­ence with tak­ing 9 mg, is that I will sleep for 10-12 hours and will then awake with a nasty headache that lasts for the rest of that day. (My ex­pe­ri­ence re­minds me of the de­scrip­tions given by a lot of peo­ple who dis­cover that the dose they tried of 3mg or 1mg was too high: with the too-high dos­es, they woke feel­ing bad and with a headache. So as one would ex­pect, the right dose differs from per­son to per­son.) Mela­tonin seems to quickly lose effec­tive­ness and soon be­comes coun­ter­pro­duc­tive; :

    Large doses of mela­tonin can even be coun­ter­pro­duc­tive: Lewy et al[68] pro­vide sup­port to the ‘idea that too much mela­tonin may spill over onto the wrong zone of the mela­tonin phase-re­sponse curve’ (PRC). In one of their sub­jects, 0.5 mg of mela­tonin was effec­tive while 20 mg was not.

    My own dose of 1.5mg is not due to any real kind of ex­per­i­men­ta­tion; rather, I cre­ated a batch of about a thou­sand cap­sules us­ing split 3mg pills, have not yet used them up, and have no real in­ter­est in throw­ing them out or oth­er­wise chang­ing them. When I run out, I will ex­per­i­ment with differ­ent doses like 1mg.↩︎

  29. Sack et al 2000 found that 10mg suc­ceeded in forc­ing cir­ca­dian rhythms in the blind; they ta­pered the dose down to 0.5mg for a few sub­jects over 4 months, and the rhythms seemed to per­sist.↩︎

  30. From press re­lease sum­mary of mela­tonin test­ing:

    Can mela­tonin help you sleep? “Mela­tonin sup­ple­ments may help some peo­ple get to sleep soon­er, par­tic­u­larly those with chronic sleep­ing prob­lems, but don’t just buy any sup­ple­ment - they vary [sub­stan­tial­ly] in strength, dosage, and cost,” says Con­sumer­Lab.­com Pres­i­dent, Tod Coop­er­man, M.D. Con­sumer­Lab.­com re­cently se­lected and tested nine differ­ent mela­tonin sup­ple­ments. The test­ing showed that all con­tained their la­beled amounts of mela­ton­in, but the sug­gested daily dosage ranged from 1 mg to 50 mg [!]; and cost ranged from just 4 cents to $1.36 for an equiv­a­lent dose of mela­tonin. This means you may not be us­ing the right dose for your needs and you could be pay­ing as much as 33 times more than nec­es­sary. Con­sumer­Lab.­com also found that one sup­ple­ment failed to prop­erly dis­close all of its in­gre­di­ents.

  31. I say very pes­simistic be­cause my ac­tual price is ~1.4¢ per night. In De­cem­ber 2009, Tommy Health sold 120x3mg for $2.49; I bought 6, with ship­ping, at $20.89. Re­mem­ber­ing that I take half a pill, the price per night is , or, 1.38¢. May 2013, I tried Now Food­s’s 250x1mg mela­ton­in+­niac­in+B6+­mag­ne­sium for­mu­la­tion for $12.16 or 4.9¢ per night; the ad­di­tional parts did­n’t seem to make much differ­ence. In March 2014, I bought Na­ture’s Bounty 4x180x1mg for $19.93, or 2.77¢ per night.↩︎

  32. Like all mod­els, this is wrong. There are many ways in which it could be wrong or mis­lead­ing to value an hour of your time at min­i­mum wage or high­er. While all mod­els are wrong, some are more use­ful than oth­ers and this is a use­ful mod­el.↩︎

  33. Here’s an­other place I am be­ing overly con­ser­v­a­tive to guard against op­ti­mism on my part; the min­i­mum wage was boosted to $7.25 in 2009, which ob­vi­ously makes the gained hour that much more valu­able and con­se­quently all the fig­ures will fa­vor mela­tonin that much more.↩︎

  34. If , then x=~0.973.↩︎

  35. Ap­ply­ing the usual ‘net of a fu­ture sum’ for­mu­la, which goes , we find that 60 years from now, the $2000 is worth $92: . We can be pes­simistic and value the an­nual re­turn at $200, and sum the 60 years in Haskell with sum (map (\x -> 200 * (1-0.05)^x) [0..60]), or $38245.↩︎

  36. Many peo­ple swear by work­ing in pub­lic places like li­braries or cafes. Neeti Gupta re­marks in “Grande Wi-Fi: Un­der­stand­ing What Wi-Fi Users Are Do­ing in Coffee-Shops” (2004) that:

    …when we are alone in a pub­lic place, we have a fear of “hav­ing no pur­pose”. If we are in a pub­lic place and it looks like that we have no busi­ness there, it may not seem so­cially ap­pro­pri­ate. In coffee-shops it is okay to be there to drink coffee but loi­ter­ing is defi­nitely not al­lowed by coffee-shop own­ers, so coffee-shops pa­trons de­ploy differ­ent meth­ods to look “busy”. Be­ing dis­en­gaged is our big so­cial fear, es­pe­cially in pub­lic spaces, and peo­ple try to cover their “be­ing there” with an ac­cept­able vis­i­ble ac­tiv­i­ty.

  37. Pro­fes­sional coach P.J. Eby re­marks thatMost Akra­sia Tech­niques Are Sub­ject To ‘Meta’-Akra­sia. If you pro­cras­ti­nate tak­ing your pills or do­ing your ex­er­cis­es, your hy­genic method is un­sta­ble: the more you de­lay, the more likely you are to de­lay some more. The same is true for main­tain­ing your ‘trusted sys­tem’ in Get­ting Things Done, break­ing your tasks into Po­modor­os, or what­ever other fo­cus­ing method you use. And of course, if you put off do­ing your mo­ti­va­tion tech­nique, it’s not go­ing to mo­ti­vate you.”↩︎

  38. To clar­i­fy: In the hy­po­thet­i­cal case, why would you be will­ing to pay one hour of your time (which could be spent do­ing any­thing, even high­-qual­ity work or ex­pe­ri­ences and per­haps es­pe­cially high qual­ity work, given all the re­search on good sleep and men­tal per­for­mance) to gain a few cents by not buy­ing mela­ton­in, but not will­ing to pay one hour of easy Wikipedia edit­ing to gain many more cents?↩︎

  39. See the mul­ti­ple large stud­ies cited in “Vi­t­a­min Pills: A False Hope?”; note that at least 3 stud­ies showed in­creased dis­ease & mor­tal­ity rates as­so­ci­ated with mul­ti­vi­t­a­min us­age, and men­tions a few down­beat re­ports & com­mis­sions:

    In­ter­est­ing­ly, show no an­ti-can­cer effects (eg. lung, pro, breast, or colon can­cer) and no mortal­ity re­duc­tion in very large datasets and Cochrane re­views (some­times in­creased mor­tal­ity), and only weak ev­i­dence in ran­dom­ized tri­als mea­sur­ing el­derly in­fec­tion rates; the long-run­ning physi­cians trial found a over­all can­cer re­duc­tion for its mul­ti­vi­t­a­min pa­tients but no ben­e­fits to the vi­t­a­min E or vi­t­a­min C or beta carotene pa­tients (nor in women), with vi­t­a­min E & be­ta-carotene fin­gered as in­creas­ing mor­tal­ity .

    That’s when they don’t ac­tu­ally cause prob­lems with can­cer (eg. and ben­e­fits from ex­er­cise like , see also the post “An­tiox­i­dants and Ex­er­cise: More Harm Than Good?” or the re­view ).

    Mul­ti­vi­t­a­mins don’t have much re­search back­ing, and a risk with mul­ti­vi­t­a­mins is that they are a and an ex­am­ple of - be­cause peo­ple mis­tak­enly ex­pect ben­e­fits (large or smal­l), they feel free to act in un­healthy ways:

    The study, pub­lished on­line to­day in the jour­nal Ad­dic­tion, de­scribes two ex­per­i­ments run by the au­thors. In the first ex­per­i­ment, run as a dummy health-food test, 74 daily smok­ers were given a place­bo, but half were told they had taken a Vi­t­a­min C sup­ple­ment. The smok­ers then took a one-hour un­re­lated sur­vey dur­ing which they were al­lowed to smoke. Those who thought they had taken a vi­t­a­min pill smoked al­most twice as much as those who knew they had taken a placebo (the con­trol group) and re­ported greater feel­ings of in­vul­ner­a­bil­i­ty. The sec­ond ex­per­i­ment was an ex­panded ver­sion of the first, with 80 par­tic­i­pants taken from a larger com­mu­nity and half told they were tak­ing a mul­ti­vi­t­a­min pill. The one-hour sur­vey also con­tained ques­tions about at­ti­tudes to mul­ti­vi­t­a­mins. The smok­ers who thought they had taken a mul­ti­vi­t­a­min once again smoked more than the con­trol group. But this time, re­searchers found that among the mul­ti­vi­t­a­min group, smok­ers with more pos­i­tive at­ti­tudes to­ward mul­ti­vi­t­a­mins ex­pe­ri­enced a higher boost in per­ceived in­vul­ner­a­bil­ity and smoked even more than their less en­thu­si­as­tic coun­ter­parts. In other words, the amount of ex­tra smok­ing rose if the smoker ex­pressed a con­scious be­lief that mul­ti­vi­t­a­mins in­creased health.

    Of course, such con­trar­i­an­ism re­ceives its own crit­ics; Phil Goetz says that 3 of the ma­jor an­ti-vi­t­a­min stud­ies have fa­tal sta­tis­ti­cal flaws.↩︎