Melatonin is popularly used as a sleeping pill—although it likely helps only a small proportion of patients. But, surprise! Several double blind studies suggest that Melatonin might also help in combating Fibromyalgia pain. One study found that Melatonin improved pain due to temporomandibular joint disorders (TMD).(1) Another showed benefit for pain caused by endometriosis.(2) Now, a double-blind study from Brazil suggests that high dose Melatonin taken regularly for six weeks probably reduces fibromyalgia pain.(3)
This optimistic conclusion is tentative, since there was no true placebo group in this study. Rather, Melatonin was as or possibly more effective than Elavil (amitryptiline), a medicine which has long been used to treat fibromyalgia. Take-Home Lesson: despite, the lack of placebo, Melatonin’s relative safety suggests that physicians might consider a trial of Melatonin for their fibromyalgia patients.
The KEY STUDY: Sixty three women with fibromyalgia were randomized to receive either 25 mgs of amitriptyline or 10 mgs of Melatonin or amitryptiline and melatonin together. All doses were given at bedtime.
Patients’ kept diaries starting at baseline and through the six weeks of the study. They recorded the time and intensity of the worst pain they experienced during each 24-hour period. Intensity was scored using a Visual Analogue Scale where zero means no pain and 100 means the worst possible pain. Although patients in all three groups had less pain after six weeks than they did at baseline, patients receiving Melatonin alone or Melatonin plus amitryptiline had significantly lower pain scores than patients who received amitryptiline alone. (P<.01). Patients receiving amitryptiline alone scored about 12 points lower at six weeks compared to baseline. Those taking Melatonin alone were about 17 points lower. Those taking Melatonin plus amitryptiline were about 18 points lower.
Quality of Life was measured using the Fibromyalgia Impact Questionnaire. This questionnaire asks about symptoms and the ability to function in ten different areas, e.g., the number of days that the person was not able to work. Again, all three groups improved. Improvement was greatest for those taking both amitryptiline and Melatonin. Improvement was second best for those taking Melatonin alone and least for those taking only amitryptiline.
Researchers also measured each patient’s average pain pressure threshold (PPT) at baseline and again after six weeks. To measure PPT, increasing pressure was applied until the patient stated that the pressure began to hurt. Pain pressure threshold improved for all groups. Improvement was greater for those taking Melatonin alone or with amitryptiline. Those taking Amitryptiline alone also improved, but less so than the other groups.
Sleep quality improved by about the same degree in all three groups.
The bottom line is that improvement in pain due to Melatonin alone and/or Melatonin and Elavil together was significantly better than that obtained by treatment with Amitryptiline by itself.
The strength of this study is that the effect of Melatonin was compared to amitryptiline , a medicine that is generally believed to have a positive effect on reducing fibromyalgia pain. The study’s main weakness reflects the lack of a true placebo control group. Despite the fact that almost all fibromyalgia specialists believe amitryptiline is useful, there have been surprisingly few double blind studies done to test this belief.(4) Could all or most of the improvement in all three groups have been a placebo effect? Not likely in my opinion, but not impossible.
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For now I think it’s wise to assume that Melatonin is fairly likely to be useful. And because side effects from Melatonin are only rarely a problem, a trial of treatment with Melatonin with or without amitryptiline might be considered.
BUT, this study’s use of Melatonin was not typical of the way most people use Melatonin. When taken to treat jet lag or to induce sleep, Melatonin is usually taken for only a few days or only intermittently. In contrast, the Brazilian study gave Melatonin every night for six weeks. Pain levels were reported only during the baseline period and at the end of six weeks. So anyone using Melatonin to help Fibromyalgia pain should be prepared to take it every night for six weeks before judging whether or not it helps.
As important, the dose used was quite high, 10 mgs each night. For jet lag people usually use a dose of 0.5 mg. To induce sleep doses of 1 mg, 3 mg or 5 mg are common. And while Melatonin at lower doses is almost always safe, we have almost no published experience about long term experience with high doses as high as 10 mgs.
Hopefully, other groups will find funding enough to do further controlled studies on Melatonin for Fibromyalgia. Such studies, I expect, would include a true placebo arm. But, until then, let’s be grateful for the Brazilian group’s efforts.
1. Vidor LP, et al, Analgesic and sedative effects of melatonin in temporomandibular disorders: a double-blind, randomized, parallel-group, placebo-controlled study. J Pain Symptom Manage. 2013 Sep;46(3):422-32. doi: 10.1016/j.jpainsymman.2012.08.019. Epub 2012 Nov 27.
2. Schwertner A, Efficacy of melatonin in the treatment of endometriosis: a phase II, randomized, double-blind, placebo-controlled trial. Pain. 2013 Jun;154(6):874-81. doi: 10.1016/j.pain.2013.02.025. Epub 2013 Mar 5.
3. Azevedo de Zanette et al, Melatonin analgesia is associated with improvement of the descending endogenous pain-modulating system in fibromyalgia: a phase II, randomized, double-dummy, controlled trial, BMC Pharmacology and Toxicology 2014, 15:1-14.
4. Cochrane Database Syst Rev. 2015 Jul 31;7:CD011824. [Epub ahead of print] Moore RA1, Derry S, Aldington D, Cole P, Wiffen PJ. Amitriptyline for fibromyalgia in adults. Cochrane Database Syst Rev. 2015 Jul 31;7:CD011824. [Epub ahead of print]
Richard Podell, M.D., MPH is a graduate of Harvard Medical School and the Harvard School of Public Health. He has been treating patients with ME-CFS and Fibromyalgia for more than 20 years. A clinical professor at Rutgers-Robert Wood Johnson Medical School, Dr. Podell see patients at his Summit, NJ and Somerset, NJ offices. His website is www.DrPodell.org