Could a Biogen medication be right for you?

Your healthcare provider is your best source of information, especially when choosing treatment. Together, you decide what treatment may work best for you. Download these questions to help get the conversation started at your next appointment.


PLEGRIDY® (peginterferon beta-1a) is a prescription medicine used to treat relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.

It is not known if PLEGRIDY is safe and effective in people under 18 or over 65 years of age.

How should I use PLEGRIDY?Icon of an injection Every two weeks

  • Use PLEGRIDY exactly as your healthcare provider tells you. A healthcare provider should show you how to inject your PLEGRIDY before you use it for the first time.
  • When you use PLEGRIDY for the first time, your healthcare provider may tell you to slowly increase your dose.
  • If you are prescribed PLEGRIDY for injection under the skin (subcutaneous injection):
    • you should use a PLEGRIDY Starter Pack to slowly adjust your dose when you begin treatment.
    • inject PLEGRIDY under the skin of your stomach (abdomen), back of upper arm, or thigh 1 time every 14 days.
  • If you are prescribed PLEGRIDY for injection into the muscle (intramuscular injection):
    • you should use a PLEGRIDY Titration Kit to slowly adjust your dose when you begin treatment.
    • inject PLEGRIDY into your thigh 1 time every 14 days.
  • If your healthcare provider changes where you are injecting PLEGRIDY (under the skin or into the muscle), you do not need to slowly increase your dose again.
  • Change (rotate) the site you choose with each injection to help decrease the chance that you will have an injection site reaction. Do not inject into an area of the body where the skin is irritated, reddened, bruised, infected, or scarred in any way.
  • Always use a new, PLEGRIDY prefilled pen or new, unopened single dose prefilled syringe for each injection.

How could PLEGRIDY help me?

See how PLEGRIDY was shown in clinical studies to impact:

  • Relapses
  • Progression of physical disability
  • MRI brain lesions

Who should not use PLEGRIDY?

Do not take PLEGRIDY if you are allergic to interferon beta or peginterferon, or any of the other ingredients in PLEGRIDY.

Find out more about PLEGRIDY >

Proven results

Learn more about how PLEGRIDY has been shown to treat relapsing forms of MS in clinical trials.

Find out how
Doctor Discussion Guide

Start a conversation with your doctor about your relapsing MS treatment.

Get it now

Learn more about the PLEGRIDY dosing schedule.

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Understanding Important Safety Information

Before taking any treatment, it’s important to understand as much about it as possible. The Important Safety Information for a treatment describes possible side effects you may experience. It also tells you what information you need to share with your doctor before starting treatment.

On this website, the Important Safety Information appears on each specific treatment page. You'll also find the Indication, which explains the specific condition that the medication was approved to treat by the FDA.