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Can Gilenya cause headaches?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on May 30, 2022.

Official answer


Yes, headaches are a common side effect with Gilenya (fingolimod) and have been reported to occur in 10% or more of people in clinical studies.

  • In studies in over 1500 patients, headache was reported in 25% of patients taking Gilenya 0.5 mg vs. 24% of patients on placebo.
  • Migraine headache was also reported in 6% of those taking Gilenya 0.5 mg vs. 4% on placebo.
  • Headache was not a common reason patients stopped Gilenya treatment in studies. However, if you have a sudden severe headache, or a headache with fever, neck stiffness, sensitivity to light, nausea, or confusion, call your doctor or get emergency medical help right away.

Besides headache, other common side effects with Gilenya:

  • abnormal liver tests
  • diarrhea
  • cough
  • flu
  • inflammation of the sinuses (sinusitis)
  • back pain
  • stomach-area (abdominal) pain
  • pain in arms or legs

Gilenya is approved by the FDA to treat relapsing forms of multiple sclerosis (MS) in patients 10 years of age and older. It is considered an immunosuppressant. You may get serious infections more easily which may be deadly.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Does Gilenya cause any serious headaches?

Yes, a severe and sudden headache may be a symptom of Posterior Reversible Encephalopathy Syndrome (PRES) with Gilenya. A headache with a fever may also signal a serious infection of your brain and spinal cord called meningitis. If you experience a sudden severe headache or a headache with a fever, contact your doctor right away.


A serious condition called PRES (Posterior Reversible Encephalopathy Syndrome) has happened rarely in adults taking Gilenya. PRES leads to swelling and narrowing of the blood vessels in your brain. Symptoms of PRES usually get better when you stop treatment, but if PRES is left untreated, it may lead to a stroke. Delayed treatment could lead to permanent nervous system side effects.

Call your doctor right away if you have any of the following symptoms:

  • sudden severe headache
  • sudden confusion
  • sudden loss of vision or other changes in your vision
  • seizure


Gilenya can also lower the number of white blood cells (lymphocytes) in your blood, which may increase your risk for infection. A headache with fever and other symptoms can be one symptom of a serious brain and spinal cord infection (meningitis) with Gilenya.

Call your doctor right away if you have any of these symptoms of an infection during treatment with Gilenya, and for 2 months after your last dose:

  • fever
  • tiredness
  • body aches
  • chills
  • nausea
  • vomiting
  • headache with fever, neck stiffness, sensitivity to light, nausea, confusion (these may be symptoms of meningitis, an infection of the lining around your brain and spine)

Your numbers of white blood cells will normally go back to normal within 2 months of stopping treatment. Your doctor may do a blood test to check your white blood cells before you start taking this medicine.

Do not stop Gilenya treatment unless your doctor instructs you to stop this medicine.

This is not all the information or side effects you need to know about Gilenya (fingolimod) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.


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