Dimethyl Fumarate

Dimethyl Fumarate
Dimethyl Fumarate


Dimethyl fumarate is used to treat adults with various forms of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control) including:

  • clinically isolated syndrome (CIS; nerve symptom episodes that last at least 24 hours),
  • relapsing-remitting forms (course of disease where symptoms flare up from time to time), or
  • secondary progressive forms (course of disease where relapses occur more often).

Dimethyl fumarate is in a class of medications called Nrf2 activators. It works by decreasing inflammation and preventing nerve damage that may cause symptoms of multiple sclerosis.

Side Effects Of Dimethyl Fumarate

Dimethyl fumarate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • warmth, redness, itching, or burning of the skin
  • diarrhea
  • nausea
  • vomiting
  • heartburn

Some side effects can be serious. If you experience any of these symptoms, stop taking dimethyl fumarate and call your doctor immediately or get emergency medical treatment:

  • difficulty swallowing or breathing
  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • hives
  • rash
  • itching
  • hoarseness
  • vision problems
  • weakness on one side of the body or clumsiness of the arms or legs that worsens over time
  • changes in vision
  • changes in your thinking, memory, or awareness that leads to confusion and personality changes
  • extreme tiredness, loss of appetite, pain in the upper right side of your stomach, dark urine, or yellowing of the skin or eyes
  • weakness on one side of the body that worsens over time; clumsiness of the arms or legs; changes in your thinking, memory, walking, balance, speech, eyesight, or strength that last several days; headaches; seizures; confusion; or personality changes
  • burning, tingling, itching, or skin sensitivity on one side of the body or face with painful rash or blisters appearing several days later
  • Dimethyl fumarate may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.

Warnings & Precautions

Before taking dimethyl fumarate:

  • tell your doctor and pharmacist if you are allergic to dimethyl fumarate, any other medications, or any of the ingredients in dimethyl fumarate capsules. Ask your pharmacist or check the manufacturer’s patient information for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have any type of infection, including infections that come and go and chronic infections that do not go away, or if you have or have ever had chickenpox or herpes zoster (shingles; a rash that can occur in people who have had chickenpox in the past); or a low white blood cell count.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking dimethyl fumarate, call your doctor.

Dimethyl Fumarate Dosage

Dimethyl fumarate comes as a delayed-release (releases the medication in the intestine to prevent break-down of the medication by stomach acids) capsule to take by mouth. It is usually taken twice a day. Take dimethyl fumarate at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dimethyl fumarate exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Dimethyl fumarate may be taken with or without food. However, if you take dimethyl fumarate with food or with a non-enteric coated aspirin (325 mg or less) 30 minutes before taking dimethyl fumarate, there is less of a chance that you will experience flushing during your treatment.

Swallow the capsules whole; do not chew, or crush them. Do not open the capsules or sprinkle the contents on food.

Your doctor will probably start you on a low dose of dimethyl fumarate and increase your dose after 7 days.

Dimethyl fumarate may help to control multiple sclerosis, but will not cure it. Continue to take dimethyl fumarate even if you feel well. Do not stop taking dimethyl fumarate without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor and the laboratory. Your doctor may order a blood test before you begin your treatment and may order certain lab tests during your treatment to check your body’s response to dimethyl fumarate.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.