drug_testing.jpgThe Food and Drug Administration is warning U.S. consumers that the vast majority of Internet pharmacies are fraudulent and likely are selling counterfeit drugs that could harm them.

The agency on Friday launched a national campaign, called BeSafeRx, to alert the public to the danger, amid evidence that more people are shopping for their medicine online, looking for savings and convenience.

Instead, they're likely to get fake drugs that are contaminated, are past their expiration date or contain no active ingredient, the wrong amount of active ingredient or even toxic substances such as arsenic and rat poison.

They could sicken or kill people, or cause them to develop a resistance to their real medicine.