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How long can you take Tecfidera?

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 17, 2023.

Official answer


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. A clinical benefit 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 was approved for MS in 2013, and long-term studies have lasted for two to six years.

Long-term treatment with Tecfidera demonstrated strong and sustained effectiveness in patients who were newly diagnosed. The earlier treatment with Tecfidera is started in MS patients, the better the outcomes seem to be. After six years the most common side effects were:

  • back, stomach, arm, or leg pain
  • diarrhea
  • fatigue
  • flushing
  • headache
  • infections
  • MS relapse
  • runny nose
  • sore throat.

  • Gold R, Giovannoni G, Phillips JT, Fox RJ, Zhang A, Marantz JL. Sustained Effect of Delayed-Release Dimethyl Fumarate in Newly Diagnosed Patients with Relapsing-Remitting Multiple Sclerosis: 6-Year Interim Results From an Extension of the DEFINE and CONFIRM Studies. Neurol Ther. 2016;5(1):45-57. doi:10.1007/s40120-016-0042-8
  • Tecfidera (dimethyl fumarate) 02/2020 Biogen Inc.

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