Melatonin for Fibromyalgia and Chronic Fatigue Syndrome

Melatonin supplements are best known as sleep aids. The supplements contain a synthetic form of a hormone that your body produces to help regulate the sleep cycle and perform a variety of other functions.

Young woman sleeping on bed in bedroom
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While not all of the benefits attributed to melatonin supplements are supported by solid research, some studies suggest it may help:

  • Reduce symptoms of jet lag
  • Improve the sleep disorder called delayed sleep phase syndrome
  • Calm anxiety before surgery

Melatonin is also used for insomnia and to help improve sleep problems associated with menopause. It may also have analgesic effects to help reduce pain and anti-inflammatory and antioxidant properties.

How It Works

In a healthy person, natural melatonin levels rise as it gets dark outside, and that helps make you tired. Your body uses the neurotransmitter serotonin to make melatonin. People with fibromyalgia and chronic fatigue syndrome are believed to have dysfunctional serotonin metabolism.

Does that mean these conditions are linked to melatonin problems as well? It actually may not, but research on that isn't totally clear.

Melatonin for Fibromyalgia

Early research on melatonin for fibromyalgia suggested that people with this condition have lower night-time levels of melatonin, which may make it hard to fall asleep and leave you tired the next day. That lead to a belief that melatonin supplements may be an effective treatment.

However, in later research, melatonin levels were normal or even increased compared to healthy controls. Still, several studies suggest a potential benefit of melatonin supplementation for symptoms.

A systematic review published in 2020 in Complementary Therapies in Clinical Practice analyzed four studies on melatonin for fibromyalgia and found that all studies showed improvements in symptoms. However, the authors cautioned that high-quality clinical trials on melatonin for fibromyalgia are needed since the designs of the studies varied.

Fibromyalgia research is plagued with inconsistency, which complicates the treatment process. And it's not just research—many people with fibromyalgia experiment with melatonin. Some report that it works well for helping them sleep, while others say it has no effect whatsoever.

Melatonin for Chronic Fatigue Syndrome

According to research, chronic fatigue syndrome doesn't appear to be linked to low melatonin levels. In fact, one study suggested that adolescents with this condition may actually have elevated levels. Several studies state that there's no indication for melatonin in chronic fatigue syndrome.

An exception is a 2006 study published in the European Journal of Neurology on people with chronic fatigue syndrome who also had delayed nocturnal melatonin secretion, which might cause difficulty falling asleep. In this subgroup, three months of treatment with melatonin was linked to improvement in fatigue, concentration, motivation, and activity.

As with fibromyalgia, you can find people with chronic fatigue syndrome who report improvement with melatonin as well as those who say it didn't help.


You can buy melatonin supplements over-the-counter in dosages generally ranging from 3 micrograms to 10 milligrams. Other dosages may be available as well.

Side Effects

In general, short-term use of melatonin supplements appears to be safe for most people, but the long-term risks are unclear.

Melatonin is classified as a sleep-aid supplement in the U.S., which means it isn't regulated by the Food and Drug Administration (FDA) and some products may not contain what’s listed on the product label.

There may also be a risk of allergic reactions, according to the National Center for Complementary and Integrative Health.

Some side effects noted in studies include:

  • Headache
  • Dizziness
  • Nausea
  • Sleepiness
  • Poor urine control in the evening
  • Agitation

There are also some accounts of short-term depression.

At higher doses, people may feel foggy the day after taking it. In addition, if melatonin is taken during the day, it may cause excessive sleepiness and impaired motor control.

There isn't any information about melatonin's safety during pregnancy and breastfeeding.

It's also possible that some people may develop a dependence to melatonin after using it for a long time. There are some concerns that it may have the potential to affect natural production of melatonin or be habit forming. Although, more research is needed.


Melatonin can interact with medications and other substances. For example, caffeine and prescription antidepressant fluvoxamine may inhibit the metabolism of melatonin. Melatonin may dampen the effects of the calcium-channel blocker nifedipine, and it may increase the risk of bleeding for people taking warfarin.

Always be sure to include your healthcare provider in decisions about supplementation. Your pharmacist can help you identify potentially dangerous interactions with drugs or other supplements you may be taking.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Center for Complimentary and Integrative Health. Melatonin: what you need to know.

  2. Wilhelmsen M, Amirian I, Reiter RJ, Rosenberg J, Gögenur I. Analgesic effects of melatonin: a review of current evidence from experimental and clinical studies: Analgesic effects of melatoninJournal of Pineal Research. 2011;51(3):270-277. doi:10.1111/j.1600-079X.2011.00895.x

  3. Mount Sinai. Melatonin.

  4. Hemati K, Amini Kadijani A, Sayehmiri F, et al. Melatonin in the treatment of fibromyalgia symptoms: A systematic reviewComplementary Therapies in Clinical Practice. 2020;38:101072. doi:10.1016/j.ctcp.2019.101072

  5. Josev EK, Jackson ML, Bei B, et al. Sleep quality in adolescents with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)Journal of Clinical Sleep Medicine. 2017;13(09):1057-1066. doi:10.5664/jcsm.6722

  6. Heukelom RO, Prins JB, Smits MG, Bleijenberg G. Influence of melatonin on fatigue severity in patients with chronic fatigue syndrome and late melatonin secretionEur J Neurol. 2006;13(1):55-60. doi:10.1111/j.1468-1331.2006.01132.x

  7. Sleep Foundation. Melatonin side effects.

  8. Poison Control. Potential uses and benefits of melatonin.

  9. St. Luke's Hospital. Complementary and alternative medicine: possible interactions with melatonin.

By Adrienne Dellwo
Adrienne Dellwo is an experienced journalist who was diagnosed with fibromyalgia and has written extensively on the topic.