Frequently asked questions

Get the answers you need about treating relapsing MS with Tecfidera® (dimethyl fumarate).

What should I do before I start taking TECFIDERA?

To get started with TECFIDERA, you need one blood draw and you can begin treatment. You can expect your healthcare provider to check your white blood cell count before you take TECFIDERA and occasionally during treatment. Your healthcare provider should also run blood tests to check your liver function before starting TECFIDERA and as necessary during treatment.

How should I take TECFIDERA?

When taking TECFIDERA, it's important to keep the following in mind:

  • Take TECFIDERA exactly as your healthcare provider tells you to take it
  • The recommended starting dose is one 120 mg pill taken by mouth 2 times a day for 7 days
  • The recommended dose after 7 days is one 240 mg pill taken by mouth 2 times a day
  • TECFIDERA can be taken with or without food
  • Swallow TECFIDERA whole. Do not crush, chew, or sprinkle pill contents on food
  • Protect TECFIDERA from light. You can do this by storing the pills in their original container
  • If you take too much TECFIDERA, call your healthcare provider or go to the nearest hospital emergency room right away

Read more about TECFIDERA dosing.

I missed a dose of TECFIDERA. How can I remember to take it?

Taking TECFIDERA exactly as prescribed by your healthcare provider gives you the best chance of getting its full benefits. Recommended dosing for TECFIDERA is one pill taken twice a day. We have several tips that could help you stay on track with treatment.

Can I take TECFIDERA if I'm pregnant?

There isn't enough data on the development risk associated with the use of TECFIDERA in pregnant women, including whether exposure is harmful to the mother or to the development of the fetus. Be sure to speak to your healthcare provider as soon as you learn that you are pregnant or if you're planning to become pregnant.

If you're pregnant while taking TECFIDERA, talk to your healthcare provider about enrolling in the TECFIDERA Pregnancy Registry to monitor your health and the health of your baby.

Does TECFIDERA have serious side effects?

Some serious side effects of TECFIDERA include:

  • allergic reactions
  • PML (a rare brain infection that usually leads to death or severe disability)
  • decreases in your white blood cell count
  • liver problems
  • herpes zoster infections (shingles), including central nervous system infections
  • other serious infections

What are the most common side effects of TECFIDERA?

Flushing and stomach problems are the most common side effects of TECFIDERA. Flushing symptoms are usually described as redness, itching, or rash. Stomach symptoms include nausea, vomiting, diarrhea, stomach pain, or indigestion. 

Learn more about the most common side effects of TECFIDERA and how they tended to decrease over time in clinical trials.

What should I do if I experience common side effects?

If you're experiencing any of the common side effects of TECFIDERA, talk to your healthcare provider about trying the tips below: 

  • Tips for flushing

Taking a non-coated aspirin (up to 325 mg) half an hour before taking TECFIDERA may help with flushing. Another tip that may help is taking TECFIDERA after a meal.

  • Tips for stomach problems

Taking TECFIDERA with food may help with stomach problems.* High-fat foods like peanut butter, cheese or yogurt may be particularly helpful. If you decide to take TECFIDERA with food, it should be taken after you eat. Visit the USDA website for more about how fats fit into a healthy diet.

You can also ask your healthcare provider or pharmacist about over-the-counter medicines, like antacids, since that may help.* Read more about tips for handling the most common side effects.


*In a small 12-week study, people recorded their experience of managing stomach problems while on TECFIDERA. They found that taking it with food or over-the-counter medications could help.

How long do common side effects last?

In clinical trials, common side effects tended to happen earlier in treatment and usually decreased over time. Keep in mind that everyone is different and may react differently to the same medication.

What’s PML?

PML is a rare brain infection that usually leads to death or severe disability over a period of weeks or months. Tell your healthcare provider right away if you get any of these symptoms of PML:

  • weakness on one side of the body that gets worse
  • clumsiness in your arms or legs
  • vision problems
  • changes in thinking and memory
  • confusion
  • personality changes

How effective is TECFIDERA?

How can I tell if TECFIDERA is working?

Talking to your healthcare provider about the results of your MRI could help with the management of your relapsing multiple sclerosis (MS). Lesions revealed on an MRI scan may help your healthcare provider determine how well your treatment is working.

How does TECFIDERA work?

It is unknown exactly how TECFIDERA works in the body, but researchers have discovered what it does in the cells.

  • Oxidative Stress

During inflammation, the body produces toxins that can cause oxidative stress on the cells. When this stress builds up, it can damage or even destroy healthy cells in different parts of the body, including the central nervous system (CNS). 

  • Nrf2 Pathway

One way the body reacts to oxidative stress is through a pathway called Nrf2, short for nuclear factor (erythroid-derived 2)-like 2. This pathway is an important part of a complex communication system involved in the body's response to oxidative stress. 

  • Dimethyl Fumarate

Researchers have learned that dimethyl fumarate leads to activation of the Nrf2 pathway in our cells. Much about how TECFIDERA works in the body remains unknown, but talking with your doctor can help you learn more about your treatment options.

What kinds of events does TECFIDERA offer, and how can I sign up?

TECFIDERA offers free educational webinars and live events throughout the year. Some of the live events may even take place in your area! We encourage you to bring your care partner or friend along with you to any TECFIDERA event. It's a nice way for them to learn more about relapsing MS while you expand your support network.

To sign up, just go to Find events, select the TECFIDERA event you’re interested in, and click on “Register.”

Why should I join a TECFIDERA event?

TECFIDERA events are great opportunities to connect with others in your area who are living with relapsing multiple sclerosis (MS). You can learn more about TECFIDERA, hear inspirational stories, and get answers to your questions. Be sure to talk to your healthcare provider, who is always your primary resource when it comes to your relapsing MS and your treatment.

What kind of support does TECFIDERA offer?

Biogen, the maker of TECFIDERA, is here to support you through Biogen Support Services. By joining, you’ll get tips, tools, and personalized assistance for your relapsing MS, including: 

  • Free access by phone to Nurse Educators 24/7
  • A variety of financial and insurance support services, and our Biogen Copay Program (if you're eligible)
  • Information about TECFIDERA treatment and support services
  • Support is also available in Spanish

We encourage you to learn more about the support that comes with TECFIDERA. Remember, your healthcare provider is your first source of information.

What can I do if my insurance doesn't cover TECFIDERA?

Biogen offers financial and insurance support. This includes speaking with Support Coordinators, who may be able to help you navigate insurance coverage, the Biogen Copay Program and Free Drug program,* and support finding assistance through charitable organizations.
*For eligible patients only.

How can I find out if I’m eligible for the Biogen Copay Program?

With the Biogen Copay Program, commercially insured patients may lower their out-of-pocket costs to as little as $0. Call Biogen Support Services at
1-800-456-2255
to see if you’re eligible.

*Depending on your income or, in some cases, if your medication is obtained from an out-of-network provider, there may be an annual cap that limits the amount of assistance that you can receive over one year. Federal and state laws and other factors may prevent or otherwise restrict eligibility. People covered by Medicare, Medicaid, the VA/DoD, or any other federal plans are not eligible to enroll. You are eligible to enroll in the Biogen Copay Program for as long as it is offered and you are treated with a Biogen relapsing MS medication.

How can a Nurse Educator help me?

Nurse Educators are all registered nurses trained to provide you and your care partner additional support along your relapsing MS journey. This includes answering questions about relapsing MS, helping you plan conversations with your healthcare provider, and directing you to services and support available.

Biogen Support Services offers free access to Nurse Educators 24/7. To reach one, call 1-800-456-2255. Support is also available in Spanish.

Explore topics:

TAKING TECFIDERA

What should I do before I start taking TECFIDERA?

To get started with TECFIDERA, you need one blood draw and you can begin treatment. You can expect your healthcare provider to check your white blood cell count before you take TECFIDERA and occasionally during treatment. Your healthcare provider should also run blood tests to check your liver function before starting TECFIDERA and as necessary during treatment.

How should I take TECFIDERA?

When taking TECFIDERA, it's important to keep the following in mind:

  • Take TECFIDERA exactly as your healthcare provider tells you to take it
  • The recommended starting dose is one 120 mg pill taken by mouth 2 times a day for 7 days
  • The recommended dose after 7 days is one 240 mg pill taken by mouth 2 times a day
  • TECFIDERA can be taken with or without food
  • Swallow TECFIDERA whole. Do not crush, chew, or sprinkle pill contents on food
  • Protect TECFIDERA from light. You can do this by storing the pills in their original container
  • If you take too much TECFIDERA, call your healthcare provider or go to the nearest hospital emergency room right away

Read more about TECFIDERA dosing.

I missed a dose of TECFIDERA. How can I remember to take it?

Taking TECFIDERA exactly as prescribed by your healthcare provider gives you the best chance of getting its full benefits. Recommended dosing for TECFIDERA is one pill taken twice a day. We have several tips that could help you stay on track with treatment.

Can I take TECFIDERA if I'm pregnant?

There isn't enough data on the development risk associated with the use of TECFIDERA in pregnant women, including whether exposure is harmful to the mother or to the development of the fetus. Be sure to speak to your healthcare provider as soon as you learn that you are pregnant or if you're planning to become pregnant.

If you're pregnant while taking TECFIDERA, talk to your healthcare provider about enrolling in the TECFIDERA Pregnancy Registry to monitor your health and the health of your baby.

Side effects

Does TECFIDERA have serious side effects?

Some serious side effects of TECFIDERA include:

  • allergic reactions
  • PML (a rare brain infection that usually leads to death or severe disability)
  • decreases in your white blood cell count
  • liver problems
  • herpes zoster infections (shingles), including central nervous system infections
  • other serious infections

What are the most common side effects of TECFIDERA?

Flushing and stomach problems are the most common side effects of TECFIDERA. Flushing symptoms are usually described as redness, itching, or rash. Stomach symptoms include nausea, vomiting, diarrhea, stomach pain, or indigestion.

Learn more about the most common side effects of TECFIDERA and how they tended to decrease over time in clinical trials.

What should I do if I experience common side effects?

If you're experiencing any of the common side effects of TECFIDERA, talk to your healthcare provider about trying the tips below:

  • Tips for flushing

Taking a non-coated aspirin (up to 325 mg) half an hour before taking TECFIDERA may help with flushing. Another tip that may help is taking TECFIDERA after a meal.

  • Tips for stomach problems

Taking TECFIDERA with food may help with stomach problems.* High-fat foods like peanut butter, cheese or yogurt may be particularly helpful. If you decide to take TECFIDERA with food, it should be taken after you eat. Visit the USDA website for more about how fats fit into a healthy diet.

You can also ask your healthcare provider or pharmacist about over-the-counter medicines, like antacids, since that may help.* Read more about tips for handling the most common side effects.

*In a small 12-week study, people recorded their experience of managing stomach problems while on TECFIDERA. They found that taking it with food or over-the-counter medications could help.

How long do common side effects last?

In clinical trials, common side effects tended to happen earlier in treatment and usually decreased over time. Keep in mind that everyone is different and may react differently to the same medication.

What’s PML?

PML is a rare brain infection that usually leads to death or severe disability over a period of weeks or months. Tell your healthcare provider right away if you get any of these symptoms of PML:

  • weakness on one side of the body that gets worse
  • clumsiness in your arms or legs
  • vision problems
  • changes in thinking and memory
  • confusion
  • personality changes
Effectiveness

How effective is TECFIDERA?

In clinical studies, TECFIDERA was shown to:

How can I tell if TECFIDERA is working?

Talking to your healthcare provider about the results of your MRI could help with the management of your relapsing multiple sclerosis (MS). Lesions revealed on an MRI scan may help your healthcare provider determine how well your treatment is working.

How does TECFIDERA work?

It is unknown exactly how TECFIDERA works in the body, but researchers have discovered what it does in the cells.

  • Oxidative Stress

During inflammation, the body produces toxins that can cause oxidative stress on the cells. When this stress builds up, it can damage or even destroy healthy cells in different parts of the body, including the central nervous system (CNS).

  • Nrf2 Pathway

One way the body reacts to oxidative stress is through a pathway called Nrf2, short for nuclear factor (erythroid-derived 2)-like 2. This pathway is an important part of a complex communication system involved in the body's response to oxidative stress.

  • Dimethyl Fumarate

Researchers have learned that dimethyl fumarate leads to activation of the Nrf2 pathway in our cells. Much about how TECFIDERA works in the body remains unknown, but talking with your doctor can help you learn more about your treatment options.

TECFIDERA events

What kinds of events does TECFIDERA offer, and how can I sign up?

TECFIDERA offers free educational webinars and live events throughout the year. Some of the live events may even take place in your area! We encourage you to bring your care partner or friend along with you to any TECFIDERA event. It's a nice way for them to learn more about relapsing MS while you expand your support network.

To sign up, just go to Find events, select the TECFIDERA event you’re interested in, and click on “Register.”

Why should I join a TECFIDERA event?

TECFIDERA events are great opportunities to connect with others in your area who are living with relapsing multiple sclerosis (MS). You can learn more about TECFIDERA, hear inspirational stories, and get answers to your questions. Be sure to talk to your healthcare provider, who is always your primary resource when it comes to your relapsing MS and your treatment.

Finding support

What kind of support does TECFIDERA offer?

Biogen, the maker of TECFIDERA, is here to support you through its Biogen Support Services. By joining, you’ll get tips, tools, and personalized assistance for your relapsing MS, including:

  • Free access by phone to Nurse Educators 24/7
  • A variety of financial and insurance support services, and our Biogen Copay Program (if you're eligible)
  • Information about TECFIDERA treatment and support services
  • Support is also available in Spanish

We encourage you to learn more about the support that comes with TECFIDERA. Remember, your healthcare provider is your first source of information.

What can I do if my insurance doesn't cover TECFIDERA?

Biogen offers financial and insurance support. This includes speaking with Support Coordinators, who may be able to help you navigate insurance coverage, a the Biogen Copay Program and Free Drug Program,* and support finding assistance through charitable organizations.

*For eligible patients only.

How can I find out if I’m eligible for the Biogen Copay Program?

With the Biogen Copay Program, commercially insured patients may lower their out-of-pocket costs to as little as $0. Call Biogen Support Services at
1-800-456-2255
to see if you’re eligible.

*Depending on your income or, in some cases, if your medication is obtained from an out-of-network provider, there may be an annual cap that limits the amount of assistance that you can receive over one year. Federal and state laws and other factors may prevent or otherwise restrict eligibility. People covered by Medicare, Medicaid, the VA/DoD, or any other federal plans are not eligible to enroll. You are eligible to enroll in the Biogen Copay Program for as long as it is offered and you are treated with a Biogen relapsing MS medication.

How can a Nurse Educator help me?

Nurse Educators are all registered nurses trained to provide you and your care partner additional support along your relapsing MS journey. This includes answering questions about relapsing MS, helping you plan conversations with your healthcare provider, and directing you to services and support available.

Biogen Support Services MS offers free access to Nurse Educators 24/7. To reach one, call
1-800-456-2255
. Support is also available in Spanish.