Peginterferon Beta-1a
Plegridy (peginterferon beta-1a) is a disease-modifying therapy used to treat relapsing forms of multiple sclerosis (MS). It is administered by subcutaneous injection, typically every two weeks, and works by modifying the body's immune response to reduce MS relapse frequency and slow disability progression.
Plegridy is an injectable interferon therapy for relapsing forms of multiple sclerosis that helps reduce relapses and slow disease progression.
Key facts at a glance
- RxNorm
- 1546173
- Generic
- Plegridy
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Plegridy is approved for the treatment of relapsing forms of multiple sclerosis, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults.
As an interferon beta-1a, Plegridy has immunomodulatory properties that reduce inflammation and autoimmune activity in the central nervous system, though its exact mechanism in MS is not fully characterized.
Common side effects include injection site reactions, flu-like symptoms, fever, and headache. It may cause liver problems, depression, and blood abnormalities. Patients should be monitored regularly and women should not use it during pregnancy. Patients must be educated on proper injection technique and recognizing signs of serious adverse reactions.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy