What are the reasons to try a new multiple sclerosis (MS) treatment? Are there unpleasant side effects? If so, how are they treated?

There are two main reasons for switching to a new MS therapy:

  • Your current treatment is no longer working.
  • The side effects of your current treatment make it difficult to continue.

There may be other reasons, too. For instance, maybe there’s been a change to your insurance coverage. The priority is finding a therapy that is either more effective or minimizes the side effects you’re currently experiencing.

Your neurologist will guide you through the process of selecting and starting a new treatment. Everybody is different. You might experience some side effects or no side effects at all.

Does the frequency or severity of my MS relapses pose any long-term risks?

Most neurologists believe that reducing the frequency and severity of MS relapses may help prevent long-term disability. This is supported by the observation that a higher relapse rate is associated with long-term disability.

Moreover, incomplete recovery following a relapse (a hallmark of a more severe attack) is also linked to long-term disability.

However, other studies suggest that long-term worsening might not be completely dependent on MS relapses. Rather, it's related to neurodegeneration that occurs throughout the disease course.

In short, relapses likely contribute (at least in part) to long-term disability in MS.

How many relapses is ‘normal’ for each year?

MS relapses are more common early in the disease course and diminish over time. MS patients experience one relapse every one to three years. Most people who are on effective treatment (or in the later stages of the disease) experience few clinical attacks.

Are there any risks of switching to a new MS medication if the one I’m on isn’t working?

Blood and other diagnostic tests are performed before starting a new therapy to ensure the treatment is safe for you. There is little risk of switching to a new medication, other than medication-specific risks and side effects.

The National Multiple Sclerosis Society also has a comprehensive summary of different MS disease-modifying therapies.

One important note is that abrupt discontinuing of natalizumab (Tysabri) or fingolimod (Gilenya) without starting a new MS therapy might increase the risk of a rebound relapse. Therefore, don’t stop an MS treatment without first speaking with your neurologist.

Can age impact the effectiveness of a treatment plan? If so, how?

Yes. Younger individuals with MS have greater autoimmune activity and tend to respond to MS therapies better than older individuals. For this reason, starting an effective MS disease-modifying therapy at the time of diagnosis is important for preventing long-term disability.

I have new symptoms. How will I know if these are related to my MS, side effects to current treatment, or a different issue entirely?

Before starting a new MS therapy, learn about the potential side effects from your neurologist and through sources like the National Multiple Sclerosis Society.

Common side effects can be easily identified and treated. If you experience new symptoms after starting treatment, contact your neurologist to discuss the potential causes.

What are the risks of staying on a treatment that isn’t effective?

The risk of continuing an ineffective treatment is suffering immune-mediated injury to the nervous system. While most relapses are followed by recovery early in the disease course, some can cause lasting neurologic disability.

If you experience more than one MS relapse in a year and/or rapidly worsening symptoms, contact your neurologist to discuss whether your current treatment is effective.

Where can I find more information about lifestyle modifications to add to my treatment plan?

Important lifestyle modifications include:

  • regular physical activity, which can aid recovery and build reserve against future MS injury
  • a heart-healthy diet high in fruits and vegetables, and low on processed sugars and saturated fats
  • building a social support network to maintain good emotional and mental health

Find a neurologic center with multi-disciplinary MS specialists who can provide you with personalized care.

The National Multiple Sclerosis Society also provides resources for lifestyle modifications.


Dr. Jia is a graduate of Massachusetts Institute of Technology and the Harvard Medical School. He trained in internal medicine at the Beth Israel Deaconess Medical Center and in neurology at the University of California San Francisco. He is board-certified in neurology and received fellowship training in neuroimmunology at UCSF.

Dr. Jia’s research focuses on MS genetics. He led one of the first studies to identify genetic factors that influence a progressive disease course in MS. His early work focused on interrogating genetic variation in the major histocompatibility complex and significantly advanced understanding of immune-mediated disorders including MS, rheumatoid arthritis, and HIV-1 infection.

Dr. Jia is a recipient of the HHMI Medical Fellowship, the NINDS R25 award, and the UCSF CTSI Fellowship.

Aside from being a neurologist and statistical geneticist, he is a lifelong violinist and served as Concertmaster of the Longwood Symphony, an orchestra of medical professionals in Boston.