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Interferon alfa-n3 Side Effects

Applies to interferon alfa-n3: injectable solution.


Call your doctor if your genital warts do not completely clear up within 3 months after your last injection of interferon alfa-n3.

Get emergency medical help if you have signs of an allergic reaction (hives, chest tightness, wheezing, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to interferon alfa-n3: injectable solution.


Very common (10% or more): Myalgia (45%)

Common (1% to 10%): Back pain, muscle cramps, stiff shoulders, arthralgia[Ref]


Very common (10% or more): Chills (87%), fever (81%), malaise (65%), influenza-like symptoms (30%), fatigue (14%)

Common (1% to 10%): Left groin lymph node swelling, hot sensation on bottom of feet, fatigue, edema, shaking/shivering, ringing in the ears[Ref]

Nervous system

Very common (10% or more): Headache (10%)

Common (1% to 10%): Dizziness, tongue hyperesthesia, numbness, lightheadedness, tingling of legs/feet, numbness in hands, numbness in fingers[Ref]


Very common (10% or more): Nausea (48%), vomiting (29%)

Common (1% to 10%): Dyspepsia/heartburn, diarrhea, strange taste in mouth, increased salivation, sore mouth/stomatitis, dry mouth, mucositis, constipation, upset stomach, throat tightness[Ref]


Very common (10% or more): Decreased white blood cell count (11%)

Common (1% to 10%): Abnormal hemoglobin level, abnormal platelet count[Ref]


Common (1% to 10%): Pruritus, papular rash on neck, photosensitivity, herpes labialis, sweating[Ref]


Common (1% to 10%): Depression, nervousness, insomnia, confusion, inability to concentrate[Ref]


Common (1% to 10%): Nose/sinus drainage, pharyngitis, nosebleed, coughing[Ref]


Very common (10% or more): Application site disorders (e.g., itching, pain) (12%), soreness at injection site (10%)[Ref]


Common (1% to 10%): Visual disturbances, blurred vision, pain on ocular rotation[Ref]


Common (1% to 10%): Dysuria[Ref]


Common (1% to 10%): Swollen lymph nodes[Ref]


Very common (10% or more): Chest pain (10%)

Common (1% to 10%): Hypotension, vasovagal reaction, heat intolerance, hot flush, flushed face[Ref]


Very common (10% or more): Anorexia (68%)

Common (1% to 10%): Abnormal alkaline phosphatase, thirst[Ref]


1. (2022) "Product Information. Alferon N (interferon alfa-n3)." Interferon Sciences Inc

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.