(USA TODAY) -- Scammers looking to make money off consumer fears about thisyear's severe flu season are proliferating, the Food and DrugAdministration says, causing the agency to take a hard look at productsthat make claims about protecting against the flu.

The FDAhas issued a warning letter to one, GermBullet, saying the nasalspray's claim that it is "laboratory tested and shown to reduceillness-causing bacteria, cold and flu viruses" is a "false andmisleading promotional statement."

GermBullet is a nasalspray made up of "pure essential oils," according to its website. Theproduct, sold over the counter, is made by Flu & Cold Defense LLC ofBoca Raton, Fla.

The FDA says the company is illegally selling a misbranded drug. Specifically, it says:

• GermBullet is being sold as a drug that claims to treat or cure adisease, but the company has never presented it to the FDA to be vettedas a drug.

• GermBullet's website claims it has been tested by an FDA-recognized virology lab, but no FDA-recognized lab has seen it.

The company has 15 days to answer the warning letter. If the companycontinues to make unsubstantiated claims about the product, the agencymay take enforcement action that could include seizure of the drug orcriminal prosecution, says Howard Sklamberg, director of the FDA'soffice of compliance at the Center for Drug Evaluation and Research.

The FDA's health fraud program monitors the Internet and radio and TV ads.

"This is shocking," says Simone Hobus of GermBullet's research anddevelopment department. Reached by phone, she said the company was notaware of the FDA's letter and declined to comment further.

By law, drugs are products that claim to prevent, treat or cure adisease, among other things. The FDA is responsible for the regulationof prescription and over-the-counter drugs.

This flu seasonhas spawned a number of fraudulent products that claim to treat,prevent or shorten the duration of the flu, Sklamberg says. Consumersshould beware of dietary supplements, foods such as herbal teas, andproducts such as air filters and light therapies that claim to:

  • Boost your immunity naturally without a flu shot.
  • Be a safe and effective alternative to the flu vaccine.
  • Prevent you from catching the flu.
  • Support your body's natural immune defenses to fight the flu.

Consumers should also be wary of online pharmacies selling "generic"Tamiflu or Relenza, antiviral drugs that lessen the severity andduration of flu, he says. Currently there are no FDA-approved genericsfor those drugs on the U.S. market. Sklamberg says such products couldbe counterfeit, contaminated or not stored properly to maintain quality.