Melatonin for Fibromyalgia and Chronic Fatigue Syndrome

Melatonin supplements are best known as sleep aids. The supplements contain a synthetic form of a hormone/neurotransmitter 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, melatonin is believed to:

  • Alleviate jet lag
  • Improve the sleep disorder called delayed sleep phase syndrome
  • Treat insomnia in the elderly
  • Improve sleep quality
  • Have anti-inflammatory and antioxidant properties
  • Calm anxiety
  • Lower pain levels
  • Enhance cognitive function
  • Improve glycemic control in some diabetes patients
  • Help treat menopause, irritable bowel syndrome, and seasonal affective disorder

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 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. It is not surprising then that research on the effectiveness of melatonin supplementation is split as to whether it helps relieve fibromyalgia symptoms. A 2002 study showed that it improved sleep, pain, and tender-point count while other studies show no significant improvement.

Fibromyalgia research is plagued with this kind of 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 study 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

We don't have any evidence of major toxicities associated with melatonin, even at high doses.

Minor side effects noted in studies include:

  • Headache
  • Short-term depression
  • Dizziness
  • Nausea
  • Poor urine control
  • In psychiatric patients, worsening depression

If melatonin is taken during the day, it may cause excessive sleepiness and impaired motor control.

We don't currently have information about melatonin's safety during pregnancy and breastfeeding.

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.

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.

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