Hepatitis B long-acting interferon side effects usually last about three months. Hepatitis B long-acting interferon side effects usually appear at the beginning of treatment, and after about three months of treatment, patients may become tolerant and most of the side effects can be relieved or disappear. However, fever and leukopenia in a small number of patients can last for a longer period of time, or even for the entire course of treatment. Interferon side effects can also be manifested as abnormalities in thyroid function, pulmonary fibrosis, depression, etc. The incidence of these side effects is relatively low, and they usually appear later, but are more serious. If side effects continue to worsen while a patient is undergoing treatment with Hepatitis B long-acting interferon, it is recommended that the patient consult a medical professional for evaluation to determine whether to discontinue Hepatitis B long-acting interferon.