What Is Extavia Used For?

What Is Extavia Used For? Interferon beta-1b injection is used to treat the relapsing-remitting forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. What are the side effects of Extavia? headache, muscle pain or weakness, sleep problems (insomnia), stomach or abdominal pain, swelling in your hands or feet,