When should you take tamiflu (oseltamivir)?

At symptom start. Tamiflu is for treating people 1 year and older with influenza (flu) whose symptoms started within the last two days. Tamiflu can also reduce the chance of getting the flu. Tamiflu is not a substitute for an annual flu vaccination. It is also called oseltamivir, and is a type of anti-viral. Dose is usually 75mg twice a day for 5 days. It should be started at the start of symptoms.