Carnitine for Fibromyalgia & Chronic Fatigue Syndrome

Carnitine, also called L-carnitine, helps your cells produce energy by breaking down fat. It also may help your brain utilize neurotransmitters, serotonin, and glutamate, which can be out of balance in people with fibromyalgia (FMS) and chronic fatigue syndrome (CFS or ME/CFS). Carnitine is also an antioxidant.

Pills on a white table
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Studies show that carnitine supplementation may help lower pain levels and boost the mental health of people with FMS, and may lessen fatigue in those with ME/CFS. Researchers also found that people with either condition tolerated carnitine well.


Studies have used a therapeutic dose of 500 mg of carnitine twice a day.

Carnitine in Your Diet

Several foods contain carnitine, including:

  • Meat (especially red meat)
  • Dairy products
  • Fish
  • Poultry
  • Tempeh (fermented soybeans)
  • Wheat
  • Asparagus
  • Avocados
  • Peanut butter

Side Effects 

High carnitine levels can lead to side effects. Serious ones include:

  • Rapid heart rate
  • Increase in blood pressure
  • Fever

Less serious ones include:

  • Vomiting
  • Nausea
  • Headache
  • Diarrhea
  • Stuffy nose
  • Restlessness
  • Difficulty sleeping (especially when taken late in the day)

Carnitine can impair thyroid hormone action, so you shouldn't take it if your thyroid hormone levels are low or borderline low. It's also not recommended for anyone on dialysis. Carnitine has a higher risk of negative interactions with other supplements, so be sure to talk to your healthcare provider and/or pharmacist before taking it. It may be helpful to have a list of all of the medications and supplements you are taking readily for that conversation.

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.