As of 2025, the U.S. Food and Drug Administration has approved more than 20 disease-modifying therapies (DMTs) for treating relapsing multiple sclerosis (MS). Research shows that DMTs can reduce how often people with MS have flare-ups, also known as relapses or attacks. These treatments can also help prevent new damage to the brain and spinal cord. Some DMTs may even help slow the progression of disability over time.

Overall, DMTs can help slow how quickly MS gets worse and keep relapsing MS under control. Types of relapsing MS include clinically isolated syndrome, relapsing-remitting MS, and active secondary progressive MS.

If you’ve been diagnosed with relapsing MS, how do you know which treatment option is best for you? For some people, how a DMT is taken and how often it’s taken are important factors. This is especially true since DMTs are usually taken long term, often for years. Some people prefer taking a pill instead of getting an injection or intravenous (IV) infusion. Others prefer a more convenient dosage schedule with medication taken only a few times a year. It can also help to know how different classes of DMTs work.

Read on to find out which DMTs are prescribed for relapsing forms of MS, how they’re taken, and why a doctor might recommend one over another.

Weighing the Risks and Benefits of DMTs

All medications, even those sold over the counter, have potential side effects. Treatments for relapsing MS are no different, and each has possible risks.

Risks Vary Between Individuals

Some side effects are common, while others are extremely rare. People who tend to be cautious may choose to avoid DMTs with the potential for serious complications, even if they’re very unlikely. Others may prioritize finding the DMT that’s most effective at slowing their MS, even if it comes with a small risk of serious side effects.

Some DMTs have contraindications — circumstances that raise the risk for serious side effects for people who have other health conditions in addition to MS. For instance:

• Some DMTs, such as natalizumab, may not be recommended for people who test positive for antibodies of the John Cunningham virus.
• Other DMTs, such as teriflunomide, may not be safe for people with liver dysfunction.

Your risk of serious side effects depends on several factors. Your doctor can help explain your risk with each medication. If you have any other health problems, your doctor may choose not to prescribe certain DMTs.

Active MS May Call for Different Treatment

Doctors may recommend DMTs based on many factors. One important factor is how active your MS is. MS can be active or inactive. Active MS means you’ve had a relapse or new lesions have shown up on an MRI scan over time, usually within a year.

When your MS is active, you’re more likely to experience new damage to the central nervous system. Doctors may suggest different DMTs based on whether your MS is considered to be active or inactive.

How Each DMT Is Taken and How Often

According to the Consortium of Multiple Sclerosis Centers (CMSC), a large organization of healthcare providers for those with MS, any approved DMT may be considered as the first treatment for someone diagnosed with a relapsing type of MS. The decision should be based on what works best for each person. Your doctor will help you decide on the treatment that works best for your needs and symptoms.

The table below lists all FDA-approved DMTs for relapsing MS, along with how each is taken and how often.

Changing DMTs

No DMT can cure or completely stop MS. According to Cleveland Clinic, your doctor may suggest switching treatments if any of the following apply:

• Your MS isn’t responding adequately to treatment. Although this is judged case by case, signs may include a relapse, new or worsening lesions, or lower scores on a neurologic exam within a year of starting treatment.
• You have significant side effects from the first therapy, or a new symptom or health condition increases your risk of side effects.
• You no longer have access to the first DMT.
• You have trouble taking the first DMT or can’t tolerate its side effects.

Let your doctor know if you think you’re having a relapse. Be sure to tell them how your relapse feels. It can sometimes be hard to tell whether you're having a true MS relapse or if your symptoms are being made worse by stress or an infection.

How Different DMTs Work

DMTs have different mechanisms of action, meaning they work in different ways. Most DMTs affect parts of the immune system to prevent autoimmune attacks — when the immune system mistakenly targets healthy tissue — on the myelin that covers nerve fibers. Understanding how DMTs work can help explain why your doctor recommends a certain medication. For instance, if you’re switching drugs because the DMT you’ve been taking hasn’t helped, your doctor will likely recommend a drug that works in a different way.

Here’s a breakdown of DMTs for relapsing MS by mechanism of action.

If you have active relapsing MS, your healthcare team may use MRI scans and biomarker tests to help you decide which DMT to try. Sometimes, the only way to know whether a DMT will work for you is to begin taking it. Many people with relapsing MS need to switch to a different DMT throughout their treatment. If you’re curious about what treatment options for relapsing MS are available for you, talk to your neurologist.

Talk With Others Who Understand

On MyMSTeam, the social network for people with multiple sclerosis and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with MS.

Do you still have questions about disease-modifying treatments for relapsing MS? Share them in the comments below, or start a conversation with others on your Activities page.