Oseltamivir in the treatment of influenza, usually to take medication for five days, because five days is the drug used in the treatment of influenza medication course, the full course of medication in order to obtain a good therapeutic effect or the body of the influenza virus is not cleared thoroughly, easy to cause recurrence of the disease. Oseltamivir is a selective influenza virus neuraminidase inhibitor drug that can help children aged one year and older and adults to treat influenza A and influenza B. It can provide antiviral effects, relieve symptoms and shorten the duration of illness. The drug’s instructions for use indicate that it should be taken for five days when used to treat influenza, so individuals should not stop taking the drug on their own to avoid recurrence and prolongation of the illness. If oseltamivir is used to prevent influenza after close contact with a person with influenza, it should be taken for a minimum of 10 days. Common adverse drug reactions to oseltamivir are nausea, vomiting and headache, which usually resolve on their own. It needs to be contraindicated in people who are allergic to the ingredients contained in the drug. It is also important to note that if oseltamivir is used to treat the flu, it should be started on the first or second day of flu symptoms. Individuals should not abuse Oseltamivir and should consult a medical professional or pharmacist before using the drug.