The duration of hair loss caused by interferon for the treatment of hepatitis B varies from person to person and it is not possible to specify an exact time. The main side effects of interferon include an initial flu-like syndrome, which occurs in about 90% of cases. Other side effects include malaise, anorexia and nausea, diarrhea, weight loss, hair loss, mood instability and depression, bone marrow suppression, and induction of autoantibodies (which can lead to thyroid abnormalities in up to 30% of patients) or worsening of autoimmune diseases. Side effects can also vary as each person responds differently to interferon, and the duration of side effects varies even more from person to person, making it impossible to say exactly how long they last. It is recommended that the need to discontinue the medication be evaluated under the supervision of a specialist after the occurrence of side effects and managed accordingly.