(CNN) -- Americans should avoid buying treatments for the H1N1 virus, commonly known as swine flu, online, the Food and Drug Administration warned.
FDA has warned Americans away from online H1N1 medication and toward regulated distribution points.
"Products that are offered for sale online with claims to diagnose, prevent, mitigate, treat or cure the 2009 H1N1 influenza virus must be carefully evaluated," FDA Commissioner Margaret Hamburg said.
The FDA issued the warning Thursday after it had purchased products over the Internet that were supposed to be Tamiflu and analyzed them. Tamiflu is one of two approved anti-viral treatments for H1N1. The other is Relenza.
None of the products received by the FDA were approved for sale in the United States, and they contained various levels of oseltamivir phosphate, the drug in Tamiflu.
"Medicines purchased from Web sites operating outside the law put consumers at increased risk due to a higher potential that the products will be counterfeit, impure, contaminated or have too little or too much of the active ingredient," Hamburg said.
In addition, the products did not arrive soon enough to treat someone infected with H1N1, or who had been exposed to the virus.