Oseltamivir, the active ingredient of Tamiflu, is an antiviral medication that prevents influenza viruses type A and type B from having an impact on the body. Tamiflu is used to treat flu symptoms in people who have had them for two days or less as a result of the influenza virus. In patients at risk of exposure who have not yet shown any symptoms, this medicine may also be used to prevent influenza. Since Tamiflu is ineffective for treating the common cold, alternate drugs should be found.

Tamiflu is prescribed for the treatment of acute and/or simple conditions brought on by influenza A and B infection in patients 2 weeks of age and older who have had symptoms for no more than 48 hours.

Although Tamiflu oral suspension and capsules can be taken with or without food, doing so can improve the medication's overall tolerability. For adults and adolescents 13 years of age and above, the recommended oral dosage of Tamiflu is 75 mg twice daily (one 75 mg capsule or the equivalent of 12.5 mL of oral suspension twice a day) for a total of 5 days.