The most common side effects with IntronA (generally reported in more than 1 patient in 10) are viral infections, pharyngitis (sore throat), anorexia (loss of appetite), depression, insomnia (difficulty sleeping), anxiety, emotional lability (mood swings), headache, impaired concentration, dizziness, cough, dyspnoea (difficulty breathing), nausea (feeling sick), diarrhoea, abdominal (tummy) pain, alopecia (hair loss), pruritus (itching), dry skin, rash, myalgia (muscle pain), arthralgia (joint pain), musculoskeletal pain (pain in the muscles and bones), reactions at the site of the injection including inflammation, fatigue (tiredness), rigors (shaking chills), fever, flu-like symptoms, asthenia (weakness), irritability and weight loss.