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Tecfidera: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on Dec 28, 2022.

1. How it works

  • Tecfidera is a brand (trade name) for dimethyl fumarate, an oral medication that may be used to treat relapsing forms of multiple sclerosis (MS) in adults.
  • Experts are not sure exactly how Tecfidera works, but there is evidence that it activates a pathway that is involved in the cellular response to oxidative stress, called the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. A metabolite of Tecfidera, monomethyl fumarate (MMF), acts as a nicotinic acid receptor agonist which can affect nerve firing. Research has shown Tecfidera reduces inflammation and protects nerve cells from damage caused by the immune system attacking the myelin sheath.
  • Tecfidera is a disease-modifying drug (DMD) and belongs to the class of medicines known as selective immunosuppressants.

2. Upsides

  • May be used to treat relapsing forms of multiple sclerosis (MS) in adults, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.
  • Tecfidera is taken orally (by mouth) twice a day.
  • Tecfidera may be stopped abruptly without precipitating any rebound disease activity (unlike some other drugs used for MS such as Tysabri or Gilenya).
  • A generic version of Tecfidera, dimethyl fumarate, is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • 40% of people report flushing as a side effect of Tecfidera. The incidence of flushing with Tecfidera can be greatly reduced by taking Tecfidera with food or taking a small dose of non-enteric coated aspirin (up to a dose of 325 mg) 30 minutes before taking Tecfidera. For most patients, symptoms of flushing are mild or moderate but less than 1% have serious flushing symptoms that led to hospitalization. 3% discontinue Tecfidera because of flushing.
  • Research has shown that up to 88% of people experience some stomach-related side effects, typically within the first three weeks of starting Tecfidera. Most stomach-related side effects are mild to moderate, with some people experiencing more than one type of event. Common events include upper abdominal pain, flatulence, nausea, diarrhea, bloating, and lower abdominal pain. Not all patients required treatment.
  • Anaphylaxis and angioedema have been reported rarely.
  • Back, stomach, arm, or leg pain, diarrhea, fatigue, flushing, headache, infections, runny nose, and sore throat are the most common long-term side effects reported with Tecfidera.
  • Tecfidera has been associated with several secondary immune-related complications, such as pronounced lymphocytopenia (decreased lymphocytes of below 500/µl have been reported in 4–6% of patients), eosinophilic gastroenteritis, severe herpes zoster, serious viral infections (eg, herpes simplex, West Nile virus), serious fungal infections (Candida and Aspergillus), and serious bacterial infections (eg, Nocardia, Listeria monocytogenes, or Mycobacterium tuberculosis).
  • Tecfidera has also been associated with progressive multifocal leukoencephalopathy (PML) an opportunistic viral infection of the brain caused by the JC virus (JCV) which is often fatal or leaves the person severely disabled. Symptoms include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes.
  • Before treatment, a baseline complete blood cell count (CBC) including lymphocyte count should be obtained, as well as liver function tests including serum aminotransferase, alkaline phosphatase, and total bilirubin levels. Cases of significant liver injury have been reported with Tecfidera; the onset has ranged from a few days to several months after initiation of treatment. Signs included serum aminotransferases more than 5-fold the upper limit of normal and elevation of total bilirubin to more than 2-fold the upper limit of normal.
  • There is no data regarding the effect of Tecfidera on the developing fetus during pregnancy. Encourage patients to enroll in the Tecfidera Pregnancy registry by calling 1-866-810-1462 or visiting

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Tecfidera is a disease-modifying drug that may be used to reduce disease progression and relapses in people with multiple sclerosis. Flushing and gastrointestinal effects are the most common initial side effects, and Tecfidera has also been associated with an increased risk of infection and rarely, some serious side effects such as progressive multifocal leukoencephalopathy (PML). It is taken orally, twice a day.

5. Tips

  • When you start Tecfidera, you will be provided with two strengths of Tecfidera. The 120 mg capsules for the 7-day starter dose and 240 mg capsules for the maintenance dose.
  • Tecfidera should be taken by mouth, twice a day, preferably with a high-fat or high-calorie meal to reduce the severity of flushing, although Tecfidera does not need to be taken with food. Flushing can affect up to 40% of people and symptoms may include a feeling of warmth, redness, itching, and/or a burning sensation. Talk to your doctor about taking a small dose of aspirin if your symptoms are intolerable.
  • Swallow Tecfidera whole and intact. Do not crush or chew nor open the capsule and sprinkle the contents on food.
  • Seek urgent medical attention if you develop any symptoms of an infection, including fever, chills, rash, body aches or pain, shortness of breath, burning when urinating, or a cough.
  • Seek urgent help if you or the person you are looking after develops weakness on one side of their body or acts clumsily, has vision disturbances, personality changes, or becomes confused.
  • Tecfidera can cause an allergic-type reaction on rare occasions. Seek urgent medical attention if you have difficulty breathing, hives, a skin rash, or swelling of the throat and tongue. Also seek urgent attention if you develop nausea or vomiting, yellowing of the eyes, brown urine, loss of appetite, severe tiredness, or abdominal pain while taking Tecfidera.
  • Do not drink excessive quantities of alcohol while you are taking Tecfidera, because it may increase the risk of side effects such as inflammation of the stomach (gastritis), especially in those with a history of stomach problems. Avoid drinking alcohol, especially strong spirits, for at least an hour after taking Tecfidera; however, one glass of alcohol, now and then at a different time of day to your Tecfidera dose is considered OK.
  • Note that alcohol can also exacerbate MS symptoms, such as imbalance, tremor, numbness, and lack of coordination, even after just one drink in some people. If alcohol affects you in this way, then it is probably better that you avoid alcohol completely.
  • Although weight gain or loss is not documented in the product information as a side effect of Tecfidera, blog sites report weight gains of 5-6lbs (2.2-2.7kg) to up to 25lbs (11.3kg) with Tecfidera, but some people report losing weight as well - up to 14 pounds. Weight gain may be due to taking Tecfidera with a high-fat or high-calorie meal or with MS itself limiting a person's ability to exercise. Weight loss may be due to gastrointestinal side effects such as nausea, abdominal pain, diarrhea, or vomiting which may occur with Tecfidera.
  • Both gastrointestinal events and flushing are more likely to occur during the first month of Tecfidera administration and tend to get better with time.
  • Tell your doctor if you are pregnant, intending to become pregnant, or breastfeeding because Tecfidera may not be suitable for you.

6. Response and effectiveness

  • The earlier treatment with Tecfidera is started in MS patients, the better the outcomes seem to be.
  • Tecfidera starts to work within 24 weeks; however, it may take up to two years for the full effects to be seen.
  • Studies report that after 2 years, compared to a placebo (an inactive pill), people taking Tecfidera were 44% to 53% less likely to relapse every year, 21% to 28% less likely to have a progression of their disability, and 74% to 90% less likely to develop new or newly enlarging T2 lesions or have Gd lesions.
  • Tecfidera can be taken for as long as it continues to have a clinical benefit and you are not experiencing intolerable or severe side effects. This means that your disease is not progressing significantly; you are not developing any new TD2 or Gd lesions, or existing lesions are not enlarging; you are not having an increase in relapses; your brain is not atrophying at a faster than normal rate; you have not experienced a prolonged reduction in lymphocyte numbers.
  • Tecfidera may be stopped abruptly without precipitating any rebound disease activity (unlike some other drugs used for MS such as Tysabri or Gilenya, for example). One study reported that most patients who started treatment with Tecfidera at a Swedish clinic had either discontinued it or switched to another treatment within two years.

7. Interactions

Medicines that interact with Tecfidera may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Tecfidera. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with Tecfidera​ include:

  • live vaccines, such as the BCG vaccine, yellow fever, measles, and mumps vaccines
  • monomethyl fumarate (additive effects)
  • other biologics or targeted treatments, such as adalimumab, tofacitinib, or etanercept (may increase the risk of serious or life-threatening infections)
  • other medications used to treat multiple sclerosis, such as fingolimod, (may increase the risk of serious or life-threatening infections).

There are no reports of an interaction between aspirin and Tecfidera or oral contraceptives and Tecfidera.

Note that this list is not all-inclusive and includes only common medications that may interact with Tecfidera. You should refer to the prescribing information for Tecfidera for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Tecfidera only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: December 27, 2022.