Oseltamivir should be taken for at least 5 consecutive days, and should be continued even if there is no longer a fever, in order to effectively suppress the influenza virus. The active metabolite of oseltamivir can selectively inhibit influenza viruses in the body. It is mainly used clinically for the treatment of influenza A and B in people aged 1 year and above, and should be administered within 48 hours of the onset of influenza symptoms, followed by 5 consecutive days of medication, which inhibits influenza viruses from infecting and replicating, and controls the viral load to a very low level, speeding up the healing of the flu. On the third day of administration, the medication may only kill viruses that are released into the bloodstream that multiply more rapidly, while viruses that are slower to react within the cells are not killed. If the medication is discontinued at this time, the virus replicates and then enters the bloodstream, which may result in the reappearance of the clinical symptoms of influenza. Common side effects of using Oseltamivir include nausea, vomiting, headache, abdominal pain, etc. It is contraindicated for those who are allergic to this product. It is recommended to adhere to the medication as prescribed by the doctor, and should not stop the medication on its own, so as not to affect the therapeutic effect.