Fremanezumab Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Mar 25, 2025.

Applies to fremanezumab: subcutaneous solution.

Serious side effects of fremanezumab

Along with its needed effects, fremanezumab may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking fremanezumab:

More common side effects

• fast heartbeat
• fever
• hives, itching, skin rash
• hoarseness
• irritation
• joint pain, stiffness, or swelling
• redness of the skin
• swelling of the eyelids, face, lips, hands, or feet
• tightness in the chest
• troubled breathing or swallowing

Other side effects of fremanezumab

Some side effects of fremanezumab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

For healthcare professionals

Applies to fremanezumab: subcutaneous solution.

General adverse events

The most commonly reported adverse reaction during clinical trials was injection site reactions.^[Ref]

Local

• Very common (10% or more): Injection site reactions (up to 45%)^[Ref]

Injection site reactions included injection site pain, induration, erythema, and pruritus.^[Ref]

Hypersensitivity

• Uncommon (0.1% to 1%): Hypersensitivity reactions
• Postmarketing reports: Anaphylaxis, angioedema

Immunologic

• Common (1% to 10%): Anti-Drug-Antibodies^[Ref]

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Further information

Fremanezumab side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer