context: Many medications can slow down MS in some people. Doctors call them disease-modifying drugs. They include: Alemtuzumab ( Lemtrada) Cladribine ( Mavenclad) Dimethyl fumarate ( Tecfidera) Fingolimod ( Gilenya) Glatiramer acetate ( Copaxone, Glatopa) Interferon beta-1a ( Avonex, Rebif ) Interferon beta-1b ( Betaseron) Mitoxantrone ( Novantrone) Natalizumab ( Tysabri) Ocrelizumab ( Ocrevus) Peginterferon beta-1a ( Plegridy) Siponimod ( Mayzent) Teriflunomide ( Aubagio) All of these drugs work by holding back or changing how your body's immune system works. These treatments are based on the fact that MS happens, at least in part, because of a mistake your immune system makes that causes it to attack the coating around your nerves, known as myelin. These medications don't cure MS, but they do lower the number of attacks, make them less severe, and prevent new brain lesions. They also slow down MS. These medications can improve the quality of life for many people with MS. Your doctor will probably suggest you start taking one as soon as you're diagnosed with relapsing-remitting MS. Things to consider include side effects they might cause, benefits of taking them, how often you take them, how you take them, and your personal concerns, priorities, and lifestyle. The goal is to find a treatment you can use comfortably and consistently. Each drug company offers customer support and may also give financial help to some people without prescription drug coverage. Here's what you need to know about some of the treatments for MS. Alemtuzumab ( Lemtrada) What it treats: Relapsing forms of MS How you take it: Through an IV infusion How often: 5 days in a row, then 3 days in a row a year later Common side effects: Rash, headache, fever, stuffy nose, nausea, joint pain Support program : 855-676-6326 Cladribine ( Mavenclad) What it treats: Relapsing and secondary progressive forms of MS How you take it: A pill by mouth How often: 4-5 days, then 4-5 days about a month later. After 1 year, this is repeated. Common side effects: Headaches, low white blood cell counts, infections Support program : 877-447-3243 Dimethyl fumarate ( Tecfidera) What it treats: Relapsing forms of MS How you take it: A pill by mouth How often: Twice daily Common side effects: Flushing, stomach pain, diarrhea, nausea, and vomiting Support program : 800-456-2255 Fingolimod ( Gilenya) : What it treats: Relapsing MS How you take it: A pill by mouth How often: Daily Common side effects: Headache, diarrhea, back pain, and abnormal liver tests Support Program: ABOVE MS 800-456-2255 Glatiramer acetate ( Copaxone) What it treats: Relapsing-remitting MS How you take it: Injection under the skin How often: Three times per week Common side effects: Skin reaction where the needle went in, weakness Support program : 800-887-8100 Interferon beta-1a ( Avonex) What it treats: Relapsing forms of MS. Also given after an initial episode of inflammation. How you take it: Injection into a muscle How often: Weekly Common side effects: Mild flu-like symptoms, reaction where the needle went in Support program : 800-456-2255 Interferon beta-1a ( Rebif) What it treats: Relapsing forms of MS How you take it: Injection under the skin How often: Three times per week Common side effects: Mild flu-like symptoms, reaction where the needle went in Support program : 877-447-3243 Interferon beta-1b ( Betaseron) What it treats: Relapsing forms of MS How you take it: Injection under the skin How often: Every other day Common side effects: Mild flu-like symptoms Support program : 800-788-1467 Mitoxantrone ( Novantrone) What it treats: Rarely used for rapidly worsening relapsing-remitting MS and for progressive-relapsing or secondary-progressive forms of MS How you take it: Through an IV infusion How often: Every 3 months or four times a year for a total of 8-12 doses Common side effects: Nausea, hair thinning, decreased white blood cell count Support program : 877-447-3243 Peginterferon beta-1a ( Plegridy) What it treats: Relapsing forms of MS How you take it: By autoinjector or prefilled syringe How often: Three times per week Common side effects: Reaction where the needle went in, flu-like symptoms Support program : 800-456-2255 Natalizumab( Tysabri) What it treats: Relapsing forms of MS How you take it: Through an IV infusion How often: Every 4 weeks Common side effects: Headache, feeling tired, and joint pain Support program : 800-456-2255 Ocrelizumab( Ocrevus) What it treats: Relapsing or primary progressive forms of MS How you take it: Through an IV infusion How often: Every 6 months Common side effects: Rash, headache, fever, nausea, infections Support program: 844- OCREVUS Siponimod ( Mayzent) What it treats: Clinically isolated syndrome, plus relapsing and secondary progressive forms of MS How you take it: A pill by mouth How often: Daily Common side effects: Headaches, high blood pressure, liver damage Support program : 877-277-2254 Teriflunomide ( Aubagio) What it treats: Relapsing forms of MS How you take it: A tablet by mouth How often: Daily Common side effects: Diarrhea, liver problems, nausea, hair loss Support program : 855-676-6326