[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Interferons](https://durgical.com/en/pharmacology/classes/interferons/) › Interferon beta

[Pharmacology](https://durgical.com/en/pharmacology/) · [Interferons](https://durgical.com/en/pharmacology/classes/interferons/)

# Interferon beta

An injected immunomodulator for relapsing multiple sclerosis. It reduces relapses but does not cure the disease.

Updated 2026-11-01

- Class: [Interferons](https://durgical.com/en/pharmacology/classes/interferons/)
- Receptor: Type I interferon receptor (IFNAR1/IFNAR2)
- ATC code: L03AB07

Also called: interferon beta-1a, interferon beta-1b, peginterferon beta-1a

## Mechanism of action

Interferon beta is a type I interferon: it binds the interferon receptor on cells and activates JAK-STAT signalling, which changes the expression of many immune genes. In multiple sclerosis this immunomodulation reduces inflammation and helps prevent nerve damage, lowering the number of relapses. The exact mechanism in multiple sclerosis is not fully understood.

- Binds the type I interferon receptor
- Activates JAK-STAT signalling
- Immune response shifts; inflammation decreases
- Fewer multiple sclerosis relapses

## Pharmacokinetics

**Absorption**
Injected subcutaneously or intramuscularly, depending on the product

**Distribution**
Pegylated form lasts longer and is injected less often

## Indications

- Relapsing forms of multiple sclerosis: clinically isolated syndrome, relapsing-remitting and active secondary progressive disease [Multiple sclerosis →](https://durgical.com/en/conditions/multiple-sclerosis/)

## Adverse effects

### Common

- Flu-like symptoms after injections
- Injection site redness, pain or bruising
- Headache and chills
- Dry eyes and dry mouth

### Serious (rare, important)

- Depression and suicidal thoughts
- Liver injury
- Seizures
- Low blood counts and severe allergic reactions

## Contraindications

- Hypersensitivity to interferon beta

## Key interactions

**Alcohol**
Can worsen side effects

**Other drugs that suppress the bone marrow or harm the liver**
Additive toxicity

## What is monitored

- Laboratory tests ordered by the doctor, including blood count and liver tests
- Mood and suicidal thoughts
- Signs of liver injury (jaundice, dark urine, pale stools)

## Administration and safety

- Injected under the skin or into the muscle depending on the product; sites are rotated
- The first dose is often given under supervision and the patient is taught to self-inject
- Single-use syringes; never reused

## Nursing care

- Teach self-injection and site rotation
- Suggest fever control as prescribed for flu-like symptoms
- Ask about mood at every visit
- Teach signs of liver problems: jaundice, dark urine, pale stools

## Pregnancy and breastfeeding

Pregnancy is discussed with the neurologist; if it occurs during treatment the doctor is told at once.

## Memory aid

Interferon BETA for «B»rain (multiple sclerosis); same flu-like effects and depression watch as alfa.

## Test yourself

Think of the answer, then tap the question to see it.

## What is interferon beta used for?

Relapsing forms of multiple sclerosis.

## Does interferon beta cure multiple sclerosis?

No. It lowers relapses and new lesions but does not cure the disease.

## Which two adverse effects of interferon beta need regular monitoring?

Depression and liver injury (also blood counts).

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## Related drugs

- [Interferon alfa](https://durgical.com/en/pharmacology/interferon-alfa/)
- [Interferon gamma](https://durgical.com/en/pharmacology/interferon-gamma/)

## Related conditions

- [Multiple sclerosis](https://durgical.com/en/conditions/multiple-sclerosis/)

[← Back to the class: Interferons](https://durgical.com/en/pharmacology/classes/interferons/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Interferon Beta-1a Subcutaneous Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a604005.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L03AB07) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 63 (McGraw Hill, 2023).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/interferon-beta/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/interferon-beta/