• gbbgrandma gbbgrandma
    May 29, 2010
    Does Melatonin Cause Diarrhea
    gbbgrandma gbbgrandma
    May 29, 2010

    I have fibromyalgia and started taking Melatonin 5 mg at bedtime along with several other drugs for sleep.  I started sleeping better and felt so much better that I knew I wouldn't continue taking it.   A few days after starting it along with Triple-Flex I started have watery diarrhea.  About 10 days later when it would not stop and I'd lost 6# I finally went to the Dr.  I had a whole bunch of stool tests done and all were negative.  I stopped the Triple-Flex and it eased up some.  But when I stopped the Melatonin it went completely away.  I started the Triple-Flex again with no problems.  A few days later, I took a melatonin and the very next morning, I had watery diarrhea.  Now I know that the melatonin is causing me watery diarrhea.  I can't find any information that this is a side-effect.  I'm wondering if others have reported this.  I've tried a lower dose, 3 mg, and I'll have some watery diarrhea for a few days.  So my options seem to be.....take the melatonin, sleep and not feel the fibro symptons, but have watery diarrhea every day of my life OR not take the melatonin, not sleep well, feel lousy, but have no diarrhea.  What's woman to do?

    READ MORE

FROM OUR EXPERTS

This question has not been answered by one of our experts yet.


FROM OUR COMMUNITY

  • healthyinterest January 27, 2014
    healthyinterest
    May 29, 2010
    I had almost identical responses as you--twenty years ago. I loved the melatonin as a much needed and only efficacious sleep aid but had awful and chronic diarrhea as a result. Did not id the reason for weeks. Sister had the same thing at the same time..I have tried occasionally to see if I'm over it, but cannot take even one dose without experiencing extreme diarrhea that then takes days/weeks to go away. 20 years ago the company producing the supplement did not realize this was a rare side effect-I called to inquire.  Now in researching online I see it is listed among side effects. I think it's very rare. I don't have any other sensitivities or any of the conditions that are listed as typical of those who do experience diarrhea in studies. So, no clue why but I can't tolerate it.  READ MORE
    • christiane.station
      September 24, 2014
      christiane.station
      September 24, 2014

      Melatonin Side Effects:

       

      I am 76, female, take medicine for blood pressure and other medical issues.  

       

      One week ago, I decided to double my dose of 10 mg. Melatonin Timed Release an hour or so before bedtime.  Sleeping through the night was my problem and the 1 pill dose wasn't working.  Since then, and thinking it was an intestinal bug that has been going around, I have had diarrhea.  Probiotic acidophilus, bland diet, rice & Pepto Bismol haven't made a difference.  In fact, by day 5, I went to my physician who asked me the usual questions.  I told him that the attacks happen mostly around bedtime and in the morning, with a period of time in the middle of the day, that nothing unusual seems to happen.  I am also fuzzy mentally, extremely tired, having some erratic heart beats and itchy skin.  He suggested Immodium, which I have taken 4 times a day for two days.  It has had no effect whatsoever.  

      This morning, after 7 trips to the bathroom, the condition was even worse.  I started thinking about what I had been doing differently and my conclusion was Melatonin.  This column gave me insights.  Further research indicates that the timed release, for intolerant people, will make the condition worse and it can take several days to normalize.  All of my symptoms are found on the Web under "side effects", if you look hard enough.  I will report after a few days and hopefully find that the whole system will have cleared up when I discontinue use of the Melatonin.  Thanks for all of your input.  Reactions such as ours are not common, however, disabling.       

      READ MORE
  • 9eleven247 July 29, 2011
    9eleven247
    May 29, 2010

    Yes diarrhea has been the side effect.

     

    My Son is 19 Non-verbal autistic.  I suspect that heat index and failed AC caused insomnia.  With working AC and 5 MG Meleatonin he falls asleep within 20 minutes and rises by 5 AM.  Some mornings earlier.

     

    There is no school Saturday and today is Friday I will not give him the melatonin

    and I am in great fear how he will sleep.  If he does not on saturday night I will

    have to try my own prescribed med.  And keep him home on monday so he can see the Dr if she is back from vacation.

    READ MORE
    • 9eleven247
      July 29, 2011
      9eleven247
      July 29, 2011

      UPDATE:

       

      I am further informed that I can only trust my personal line of sight knowledge absent which my son eats bananas hidded in the frig peel and all, grapefruit

      bitten, and sweet green pepper since he is allowed by his Mom to roam and do

      as he pleases.

      READ MORE
  • Susie Orchard February 21, 2011
    Susie Orchard
    May 29, 2010

    I also have been taking melatonin for six weeks and have been sleeping really well but have been suffering with very bad diarrhoea so have discontinued. More information needs to be given of this side effect.

    READ MORE
    • tired of being tired
      March 08, 2011
      tired of being tired
      March 08, 2011
      I have been trying to get off of ambien w/ Dr. recommended melatonin.  I managed well for 1 week then started having intermitant diarrhea, the last 13 days I am having watery stools  to 8 x day.  was going to my dr today, till I found this site.  I too have fibromyalgia and ambien has been a God send.  I began to have memory lapses and feelings of floatiness, this is going on last 2 years and I have been on ambien 10 years so I am now on the ground and much better w/o it. Etoh consumption is down to 1 to 3 drinks a week. and caffiene for one or two am coffee, decaf the rest. Now this sleeping thing........ I may be sleeping alone for a while till I can get to sleep.  Warm milk and honey for me tonite.  READ MORE
    • gbbgrandma
      March 09, 2011
      gbbgrandma
      March 09, 2011
      I also stopped taking Ambien.  I had a car wreck that damaged my car and 2 others and I didn't even know it happened!  I wasn't hurt, but I ended up in ER because the dr where I had my wreck thought I might have had a stroke.  No stroke.....but I haven't had any other problems since then.  I now take Lunesta along with melatonin.  I dropped down to 3 mg and haven't had any diarrhea problems since.  I really don't know if it's helping my sleep, but I take it anyway.  Oh....I also take trazadone for sleep.  I wouldn't sleep at all if I didn't have these meds.    READ MORE
  • kimberlylarae December 20, 2010
    kimberlylarae
    May 29, 2010

    I also have fibromyalgia and cluster headaches and I read that melatonin can help. I started taking 10mg. before bed about a week ago or so and Saturday started getting watery diarrhea and cramping. I'm on the Internet right now trying to find out if the melatonin could be the cause. Like you, I really like it and hope it isn't what is causing it (and I have two bottles of it). I'm going to stop taking it and see what happens. With my luck it will be the melatonin. I took it a few years ago and don't remember having a problem. I was taking about 9 mg. I'd like to know what you've found out about it if anything and if you have been able to continue taking it.

    READ MORE
    • gbbgrandma
      December 21, 2010
      gbbgrandma
      December 21, 2010

      I didn't find a thing on the internet about melatonin causing diarrhea.  I dropped my dose to 3mg and didn't really have any problems.  I got really constipated again and took 5 mg.  It's not causing diarrhea now, but it makes me "go".  So I routinely take it again and I'm staying fairly regular.  If you find anything, I'd love to hear about it.

      READ MORE
    • kimberlylarae
      December 21, 2010
      kimberlylarae
      December 21, 2010

      I did find out that it can cause "abdominal discomfort" and one side effect is diarhea. I think I'll stay off it for a while and then go back on with a very low dose. I included what I found but if you were doing research on it you probably already know most of it. They think it may prevent some kinds of cancer. I did find that another side effect can be itching. I've had a bad problem with that and we think caused by fibromyalgia, so I thought I would let you know that in case you should start itching you might want to discontinue the melatonin and see if that helps.

      Happy holidays,

       

      Food Sources: Oats, sweet corn, rice, ginger, tomatoes, bananas, barley, Japanese radish. Tryptophan, which can be converted by the body into melatonin, is found principally in spirulina, soy products, cottage cheese, chicken liver, pumpkin seeds, turkey, and chicken.

      Effects: Regulates the body's clock, so it can be effectively used to treat insomnia, jet lag, and depression. Unlike sleeping pills, it doesn't interfere with REM sleep (the dream state), and leave the individual feeling groggy upon wakening, and it resets the body's clock rather than just knocking the person out. It is known to produce vivid dreams. It also works as a powerful antioxidant (as much as 500 times more powerful than DMSO), and is now being tested as a possible anticancer drug (it may inhibit some types of cancers, particularly those that are hormone-related - e.g., breast cancer, prostate cancer - when taken in doses of 40 mg a day or more). It has also been shown to boost the immune system, lower cholesterol, shrink the prostate, and lower heart rate and blood pressure. Researchers are looking into it as a possible treatment or cure for such things as Alzheimer's, Parkinson's disease, AIDS, PMS, menopause, osteoporosis, Down's syndrome, and even as a birth control pill. Some suggest it may even delay the aging process, though it may not be able to reverse it (it has been shown to increase the longevity of lab rats an average of 20 percent), and it may ease some symptoms of autism, epilepsy and diabetes.

      Taking adequate amounts of vitamin B-3 can free up more tryptophan to be converted to melatonin. Vitamin B-6 can stimulate the body to produce more melatonin, as the body uses it to convert tryptophan into serotonin, which can then be converted to melatonin. Taking calcium and magnesium at night may also benefit melatonin production.

      Precautions: It should not be taken by women who are pregnant, nursing, or trying to get pregnant, as it interferes with sex hormones; healthy children, as they produce enough on their own; those with severe mental illness, as it could worsen the symptoms; those taking steroid drugs such as cortisone and dexamethasone, as it could reduce their effectiveness; and those with overactive immune system abnormalities, including lymphoma, leukemia, allergies, and autoimmune diseases such as arthritis, multiple sclerosis, and lupus, as it could worsen these conditions.

      It appears to be nontoxic, though much research still needs to be done, and harmful side effects may yet be uncovered. Most studies have been done on rats, which do not produce their own melatonin. Side effects may include depression, diarrhea, headaches, insomnia, nightmares, grogginess or fuzzy thinking upon arising from sleep, and a reduced sex drive. Taking it at the wrong time could cause problems, such as falling asleep at the wheel of a car; taking too much (more than 0.3 mg) in efforts to fall asleep could result in a melatonin hangover the next day. Paradoxically, women who take it for birth control do not get sleepy; why this happens is not known. When taken counter to the body's normal circadian rhythm (e.g., by those working night shifts), it can have negative effects on memory and cognitive processing. Optimum dosage has not yet been determined, and long-term effects are still not known. There may be a risk of contamination from viruses in the natural form, made from animals, as opposed to the synthetic form; on the other hand, most synthetic forms are manufactured outside the U.S., leaving open the question of quality control. Apart from this, natural and synthetic forms are identical. Melatonin is only effective as a sedative if the pineal gland's production is low; otherwise, doses as high as 75 to 150 mg will have no effect. It should not be used to treat insomnia, as there are numerous causes that result in a loss of sleep, and melatonin may not be effective in countering them. One study has shown that it can worsen clinical depression in some cases, and in nondepression cases can cause fatigue, confusion, and sleepiness.

      Some medications, especially hypertension medicines, can interfere or react with melatonin. The production of melatonin can also be inhibited by exposure to electromagnetic fields, lack of sunlight during waking hours, lack of darkness during sleep (caused even by such seemingly innocuous offenders as night lights), aspirin (which can cut production by 75 percent), alcohol, beta-blockers, calcium-channel blockers, sedatives (such as Prozac, Valium, and Xanax), steroids, fluvoxamine (Luvox), desipramine (Norpramin, Pertofrane), most MAO inhibitors, caffeine (including coffee, green tea, colas, and chocolate), tobacco, doses of B-12 above 3000 meg, ibuprofen, sleeping pills, tranquilizers, and indomethacin (which can completely block the nighttime increase of melatonin). Smoking one joint of marijuana, on the other hand, can increase melatonin levels in the body 4000 percent.

      The sale of melatonin is banned in Canada, France, and Britain.

      Dosage: Levels produced by the body are measured in picograms (trillionths of a gram), averaging around 10 pg per milliliter of blood per day and 50 to 150 pg per milliliter at night. Melatonin output in the body can be improved by eating the foods mentioned above; getting enough niacin, B-6, calcium, and magnesium; meditation, prayer, and other relaxation techniques; and smoking marijuana. Sublingual supplements allow the melatonin to reach the brain quicker, but a time-release supplement at bedtime is probably best, as it most mimics natural conditions. Researchers recommend taking only 0.5 to 5 mg a day one-half to one hour before bedtime, though some studies have shown that as little as 0.1 mg (equal in amount to a few grains of salt) can enhance sleep. Most pills are 2.5 to 3 mg, which, according to Dr. Russel J. Reiter, professor of neuroendocrinology at the University of Texas Health Science Center in San Antonio, may be "overkill," though probably not harmful. Women taking up to 75 mg a day for birth control research have shown no apparent side effects. Reiter himself takes less than 1 mg/day, and Ray Sahelian, M.D., does not recommend its use more than once or twice a week. On the other hand, Crook and Adderly advise its use only for combating jet lag, and Alan Gaby, M.D., who publishes the newsletter Nutrition and Healing, states, "We do not at this time believe that melatonin should be a routine part of the average nutritional-supplement program." Reiter recommends an alternative program of 100 mg of B-3, 1000 mg of calcium, and 500 mg of magnesium at night, plus 25 to 50 mg of B-6 early in the morning, to assist the body's own production of melatonin.

      READ MORE
    • tired of being tired
      March 08, 2011
      tired of being tired
      March 08, 2011

      Mayo Clinic does not recommend more than 6 mg, but I had to stop d/t severe diarrhea

      READ MORE
    • Nancy Altman
      July 12, 2011
      Nancy Altman
      July 12, 2011

      I have been using Melatonin 10mg. for almost a month, and have been experiencing watery diarrhea and itching severly for that amount of time.  My doctor has been cutting down, or cutting out a few of my other medications to rid me of both of these horrible side effects.  Nothing changed.  I never suspected it was the Melatonin.  Today, for some reason, I thought to look Melatonin up on my computer.  I was shocked to say the least.  I have been reduced to wearing diapers because there have been too many times that I have not been able to get to the bathroom, and had to throw away my underwear and some clothes.  My action has been, as of this day (July 12, 2011), to stop taking Melatonin forever.  I will let you know the results.

      READ MORE
    • gbbgrandma
      July 13, 2011
      gbbgrandma
      July 13, 2011

      I'm glad you figured it out about the melatonin.  I started taking it again, but I only use 3 mg.  I ran out and didn't take any for awhile and I really didn't notice it.  Why I bought more is beyond me.  I'm hoping to hear that the diarrhea is gone.

      READ MORE
    • cdilorenzo
      August 18, 2011
      cdilorenzo
      August 18, 2011

      I'm so glad every one posted their experiences. My husband and I are caring for his elderly mom who has alzheimers and has alot of difficulty sleeping. We started her on Melatonin at the suggestion of the neurologist, and it the beginning it seemed to be working. After about a month we were up to 12mg a she was having daily episodes of stool incontinence. She also was reduced to wearing diapers. I brought her to the Doctor had stool samples and blood work drawn, we were even considering placing her in a nursing home,... it was that bad. I can't thank all of you for sharing. We stopped the Melatonin and life in our house is so much better.

       

       

      READ MORE
    • jhp1940
      September 06, 2012
      jhp1940
      September 06, 2012

      I started taking  3 mg Melatonin about 5 weeks ago. I began having diarrhea approximately the same time. I have about 4 to 5 bouts a day and then am good the rest ofthe day. I have had problems in the past with diarrhea but not this bad. At that time the Dr changed my cholesterol medication from simvastatin to another and the diarrhea stopped. The new medication was not generic so I decided to change back. The diarrhea didn't return until  taking Melatonin. There are other nasty side affects if you have high blood pressure or other medical problems. I have noticed my heart skipping beats more than usual as well. I found these side effects by googling "Melatonin cause diarrhea?". Thanks so much for the posts about experiences with this product.

      READ MORE
  • gbbgrandma January 28, 2014
    gbbgrandma
    May 29, 2010

    I had an appt in Dec with a new GI doc.  When I mentioned the melatonin problem, he said he didn't believe it.  Geez, I take it & and I get diarrhea.  I quit it and the diarrhea goes away......several times I tried this.  What do you do when your own doc doesn't believe you?  Get a new doctor?

    READ MORE
  • sleeperless January 30, 2013
    sleeperless
    May 29, 2010

    My doctor told me to try melatonin.  I take several other meds for OCD & bi-polar and I question if he suggested that because it wasn't another narcotic. 

    Oh Lord!   I told him about it but he said it doesn't cause diarrhea... BUT have had it since last August!   I've gone off it a few times but I can stay awake for a couple days & get by w/ 4 or 5 hours of sleep.  The bottle doesn't say anything and the doctor didn't think it caused it.

    I'm so glad to find all these comments - the ones where some are saying going off of it and it went away.. oh boy.  This is the first time I'm hearing what I was figuring was the cause of that watery diarrhea - ugh!  I have been taking some OTC anti-diarrheal and it works - 1st dose & 2nd.   Then skip - the diarrhea comes back.  I didn't go to have the condition tested and so now I hear all this - I won't. 

    Some have said Benedryl would help with sleep... even the Dr.  - I'm just glad to find out this is a side affect of the melatonin.   Thanks so much for all the input!  What a relief!

    READ MORE
  • Sgt. Summers January 13, 2013
    Sgt. Summers
    May 29, 2010

    Is anyone having acid/burning diarrhea?

     

    I have been taking Melatonin 3mg for several days and the day before yesterday had a horrible day. Yesterday I took Metamucil to counter the watery (in my case also burning) diarrhea. This worked for me. I have had elevated cholesterol and urine bilirubin for two years as well as gerd. Prior to that, I was abusing alcohol but I'm sober now. The melatonin is amazing for sleep, I am tempted to stay on it despite the side effect. The dark urine which I have been told is a result of the bilirubin stopped yesterday as well as my abdominal pain. Yesterday was the first time in months that I did not have pain in my abdomen. The pain was in my upper right side, close to my back, several inches below the bottom of my shoulder blade. I went to a hospital for this several times in 2011 for this and the only diagnosis I received was GERD and prescribed omeprazole but the abdominal pain didn't stop. I think the melatonin treated this problem.

     

    I wouldn't mind losing some weight anyway so I'm drinking a lot of water and continuing the melatonin and metamucil. Sleeping is awesome, not having abdominal pain is awesome, not having dark urine is awesome. Metamucil counters the watery/burning stool well. I'll go see a doc sometime next week but I didn't take my omeprazole so I'll see if my acid reflux returns tomorrow.

    READ MORE
    • christiane.station
      September 24, 2014
      christiane.station
      September 24, 2014

      Melatonin Side Effects:

       

      I am 76, female, take medicine for blood pressure and other medical issues.  

       

      One week ago, I decided to double my dose of 10 mg. Melatonin Timed Release an hour or so before bedtime.  Sleeping through the night was my problem and the 1 pill dose wasn't working.  Since then, and thinking it was an intestinal bug that has been going around, I have had diarrhea.  Probiotic acidophilus, bland diet, rice & Pepto Bismol haven't made a difference.  In fact, by day 5, I went to my physician who asked me the usual questions.  I told him that the attacks happen mostly around bedtime and in the morning, with a period of time in the middle of the day, that nothing unusual seems to happen.  I am also fuzzy mentally, extremely tired, having some erratic heart beats and itchy skin.  He suggested Immodium, which I have taken 4 times a day for two days.  It has had no effect whatsoever.  

      This morning, after 7 trips to the bathroom, the condition was even worse.  I started thinking about what I had been doing differently and my conclusion was Melatonin.  This column gave me insights.  Further research indicates that the timed release, for intolerant people, will make the condition worse and it can take several days to normalize.  All of my symptoms are found on the Web under "side effects", if you look hard enough.  I will report after a few days and hopefully find that the whole system will have cleared up when I discontinue use of the Melatonin.  Thanks for all of your input.  Reactions such as ours are not common, however, disabling.       

      READ MORE
  • Arty December 26, 2012
    Arty
    May 29, 2010

    I started taking Melatonin 6 month ago, 5 mg before sleep. After a month I started to have the same side effects as other people here, watery diarrhea and cramps. I stopped taking Melatonin completely and the symptoms went away after a week. The solution for me was to reduce the Melatonin dosage to 2mg maximum before sleep, and to never take it on an empty stomach. As a result, I have been taking 1.5mg Melatonin at bedtime for the last 4 month with no problems at all, and sleep better.

    READ MORE
    • gbbgrandma
      December 27, 2012
      gbbgrandma
      December 27, 2012

      I'm already on 2 sleep medications for fibromyalgia, but I still don't sleep well.  I have thought about taking a small dose of melatonin to see if it helps.  Now that you have mentioned this, I think I'll try it, too.

      READ MORE
  • win3435 December 16, 2012
    win3435
    May 29, 2010

    FINALLY after 8 months of suffering I am cured. I am 70 years old. I used Melatonin every night along with 5 mg of ambieum. However. my diarrrhea was so bad, I wore heavy pads daily, changing them several times a day.  I can't tell you how many times I threw away underwear, or times I had to leave a store because it started runnung down my slacks.  My life was hell, my doctor ran all sorts of tests, including a colonoscopy and all reports were negative.  I quit taking Melatonin after hearing a report on TV on Dr, Oz show  about it's effects and within 2 days, no more diarrhea.  I have 2 bottles of the stuff and will never touch again.  My life is normal again.

     

    READ MORE
    • gbbgrandma
      December 16, 2012
      gbbgrandma
      December 16, 2012

      This side effect was mentioned on TV?  It's about time!  I'm so sorry the melatonin caused so many problems for you.  At least, you now know the cause of the diarrhea. 

      READ MORE
  • Thomas December 13, 2012
    Thomas
    May 29, 2010

    Nightly for over a month I have been taking 10 mg of a melatonin time-release product to help me fall asleep.  It works like a charm to get me to almost instant sleep. But for the last three weeks I have suffered watery diarrhea and in the process I lave lost 6 pounds.  Nothing has help stop the diarrhea.   My doctor put me on a perscription to help the symptoms with no result.  If anything, I am usually a constipator, so this bout of diarrhea is unprecidented in me.   I'm 62 years old.  

     

    So I started to inventory my supliments to see what I had changed or added in the last 30 days and Melatonin was one of the new items that I was using daily.    I am at my wits end trying to figure out what is causing the diarrhea so I Googled the issue, found this forum and I am now quitting the melatonin to see if it helps.    I'll report in a week or so.   I hope that this is the problem.  By what I read here, I think it is.

    READ MORE
    • Thomas
      December 16, 2012
      Thomas
      December 16, 2012

      Hi.. this is Thomas replying to my own post of 12/13/2012.   It's now Sunday, 12/16/2012, three days since my last dose of 10 mg of melatonin and I'm here to say that the diahrrea went away finally.    I am so relieved that I didn't have a serious condition.   Lots of things crossed my mind for the three weeks that I suffered from serious watery stools, weight loss and dehydration.   Melatonin is NOT a harmless supliment.   That stuff, while and effective sleep aid, can be dangerous.    I flushed the rest of my melatonin down the toilet.   I now use 1 MG of Valium with 25 MG of Diphenhydramin hydrochloride (antihistimine) and that mix works like a charm and it keeps me sleeping better than Melatonin did.   I must admit that Melatonin did a great job of putting me to sleep, but it didn't do a great job of keeping me to sleep.

       

      READ MORE
  • heloisa marques December 12, 2012
    heloisa marques
    May 29, 2010

    I started having severe watery  diarrhea when I begun taking 3 mg of melatonin and it took a while to discover the cause of it. By readibg this site I started considering that this might be the cause of the diarrheia and stopped taking melatonin. 

    I am astonished that nothing of this is described as a side effect for patients who take this "medicament". 
     

    READ MORE
  • kathyj December 05, 2012
    kathyj
    May 29, 2010

    I was using Melatonin 10mg for 2.5 months with excellent results for sleeping.  A week ago started having 2-3 morning episodes of diarrhoea.  I stopped taking it 3 days ago and symptoms haven't eased yet - it must build up in your system.  Good to know it's the most likely cause of digestive problems though.

    READ MORE
  • jpgma November 28, 2012
    jpgma
    May 29, 2010

    I think I just figured out why I was so sick last spring.  I just started taking the melatonin again and BAM symptoms are back.  I hope it gets out of my system quicker this time. 

    READ MORE
  • OHBuckeye October 26, 2012
    OHBuckeye
    May 29, 2010

    I had been taking over the counter melatonin without any side effects.  My doctor ran some tests and found that my cortisol levels were very low in the a.m. and my melatonin was also low.  She prescribed 1mg of melatonin to be used sub lingual.  I took my first dose last night and today I have had diarrhea and cramping.  I began researching side effects also and saw these responses.  I will not be taking this prescription again until I talk to my doctor for a solution.

     

    READ MORE
  • capnpanic October 19, 2012
    capnpanic
    May 29, 2010

    After quitting tobacco I had a very hard time sleeping.  I began taking 10 mg of melationin a night and developed watery diarrhea and cramping that lasted for about two weeks. The melatonin ran out and the gastorintestinal symptoms ceased. I never made the connection and bought some more melatonin about two months later because I really appreciate the sleep aid attributes.  After another three week bout of really unpleasant gastrointestinal side effects (I mean really unpleasant) I stopped the melatonin, ate a lot of yogurt and two days later I was pretty close to back to normal. OK, had to test it one more time and took 5 mg last night.....been crapping like a tropical bird all day.  I know everyone's system is different and this is not a peer reviewed study, just my experience.

    READ MORE
    • gbbgrandma
      October 21, 2012
      gbbgrandma
      October 21, 2012

      Experience means everything.  Years ago I was taking a medication that caused some side effects that were nasty.  A physician told me that the PDR said nothing about those side effects and therefore did not cause my problem.  Well, I stopped and they went away.  Tried it a few times....like you.  About 2 years later the PDR now lists that side effect for this medication.  So now I trust myself and my experience. 

      READ MORE
  • plh
    plh
    August 27, 2012
    plh
    plh
    May 29, 2010

    I am a pharmacist who began taking 10mg of Melatonin plus 25mg of diphenhydramine (Benadry Gen) about 1 1/2 months ago to aid in sleep. I didn't connect my diarrhea to that but I had diarrhea constantly for all that time. I read your posts on this website and decided to discontinue the melatonin and go with 50 mg diphenhydramine. It took about 5 days for the stool to begin to be firm again. However, my wife is taking 10mg of melatonin and it does not effect her at all. More research needs to be done about this side effect and why it occurs so drastically in some individuals and apparently not at all in others. I was discouraged when I didn't see it listed as a common side effect in the literature. Maybe this phenomenon occurs only in a very few people.

    READ MORE
  • plh
    plh
    August 27, 2012
    plh
    plh
    May 29, 2010

    I am a pharmacist who began taking 10mg of Melatonin plus 25mg of diphenhydramine (Benadry Gen) about 1 1/2 months ago to aid in sleep. I didn't connect my diarrhea to that but I had diarrhea constantly for all that time. I read your posts on this website and decided to discontinue the melatonin and go with 50 mg diphenhydramine. It took about 5 days for the stool to begin to be firm again. However, my wife is taking 10mg of melatonin and it does not effect her at all. More research needs to be done about this side effect and why it occurs so drastically in some individuals and apparently not at all in others. I was discouraged when I didn't see it listed as a common side effect in the literature. Maybe this phenomenon occurs only in a very few people.

    READ MORE
  • Thankful July 02, 2012
    Thankful
    May 29, 2010

    Thank you for all of your post on Melatonin. I thought that Melatonin would be a natural alternative to other sleep aids. Little did I know that it would have such an impact of my life. Like others who have posted, the main symtom was watery diarrhea. I was going to the bathroom eight to ten times a day. I kept an input (food)/ouput diary for three weeks but could see no connection to what I ate and my diarrhea. Once I sneezed and had to change my underwear because of the accompanying diarrhea. I even resorted to using my 81 year old mother's Depends a few times. I had blood test as well as stool test run; both came back negative. After reading your post, I threw the Melatonin in the trash. It took a couple of weeks, but I finally started having normal bowl movements. I never thought a solid stool could make me so happy. I hope that the distributors of this drug will at least put a warning on the bottle. If they had done that, it might not have taken me two months to figure out what was causing my problem.

    READ MORE
  • ss
    ss
    March 03, 2012
    ss
    ss
    May 29, 2010

    I tried melatonin probably 15 yrs ago, it made me so sleepy I could not get up in the morning for work. Also had the diarrhea. I tried it again after all these yrs and found if I only take 1mg, I sleep better, the diarrhea is gone but after taking it for 3+ days loose stools/cramps can be a problem. My solution is to take it for 3 to 4 days and then not take it for 3 to 4 days. Drink lots of water. The dehyration from diarrhea will make muscles cramp up. Seems to work. I have the same problem with SSRI. In my internet research I found tryptophan converts to melatonin and melatonin converts to serotonin. I have never tried tryptophan. Has anyone? The SSRI I have tried usually make me sleep better but they cause far worse next day sleepy and slow movement and diarrhea than melatonin.  I have found that using progestrone cream/lotion every night before bed helps without side effects. You have to use it every night for it to build up. Also I had a prescription for Prometrium, an oral progestone considered natural, for me if I took two it felt like I had taken a valium and the muscles relaxed vs valium made me not care and the muscles still painfully tight. No side effects with the progestrone. Getting a doctor to prescribe it is difficult. It is not a mainstream drug, but a harmless old one. I must note as I have gotten older I don't think the fibromyalgia pain is as bad as it was when I was young, but my ability to function and tolerate has decreased. I don't have the strength to keep moving though the pain.  I think there is a definate relationship to balanced hormones and fibromyalgia. I've searched for answers for 30 years, still nothing has really worked. These days I use more herbal and vitamins. 

    READ MORE
  • Val2u August 18, 2011
    Val2u
    May 29, 2010

    I have been taking melatonin to help with sleep and have been having watery diarrhea too.  I too could not find anything in the side effects except stomach upset.  Now that I know that this is causing my diarrhea, I will have to reconsider taking it.  I was looking for something besides a prescription so I have heard that Valerian works as well.  I guess I will try that!

    READ MORE
You should know Answers to your question are meant to provide general health information but should not replace medical advice you receive from a doctor. No answers should be viewed as a diagnosis or recommended treatment for a condition. Content posted by community members does not necessarily reflect the views of Remedy Health Media, which also reserves the right to remove material deemed inappropriate.