Oseltamivir, commonly known by its brand name Tamiflu, is an antiviral medication used primarily to treat and prevent influenza (flu) infections. The standard dosage for treating the flu is 75 mg, typically administered twice daily for five days. It works by inhibiting the neuraminidase enzyme found on the surface of the influenza virus. This enzyme is crucial for the virus's replication and spread within the respiratory tract. By blocking neuraminidase, Oseltamivir helps to reduce the severity and duration of flu symptoms.Effective when started within 48 hours of flu symptoms' onset, Oseltamivir can shorten the duration of the illness and may also prevent complications associated with the flu, such as pneumonia. It's also prescribed as a preventive measure for individuals who have been exposed to the virus but are not yet showing symptoms. While Oseltamivir is generally well-tolerated, some side effects may occur, including nausea and headache. As with any medication, it's important to follow the prescribed dosage and consult a healthcare professional for personalized advice and potential interactions with other medications.