good question.

Tamiflu is a drug designed to prevent and treat the symptoms of the influenza virus, commonly referred to as the flu. Because of the recent sudden spread of the swine flu, many people have begun buying cheap Tamiflu online as a way of lowering their chances or preventing them from contracting the swine flu. Tamiflu, which is really the brand name version of the generic drug Oseltamivir, is an antiviral drug that is traditionally used in the treatment and prevention of Influenza virus A and Influenza virus B for a maximum of six weeks of treatment.

Tamiflu works best when taken within two days of the first appearance of symptoms because treatment becomes more difficult after the virus has spread to more cells in the body. Tamiflu works by stopping or at least slowing the replication of the virus after it has been contracted, and prevents the virus from infecting cells as a preventative treatment. For Tamiflu to work most effectively, some doctors have suggested that the drug be taken for longer than the recommended dosage as the virus still may have replicating abilities in some patients after six weeks, which increases the risk of viral resistance and mutation.

Hope this helps!