While it’s certainly possible to order Viagra and other prescription medications online, buyers need to be sure that they’re dealing with a reliable U.S.-based supplier that sells only genuine FDA-approved drugs.

But be forewarned. Forbes reported in September 2013 that data presented at the World Meeting on Sexual Medicine in late 2012 showed that 77 percent of Viagra purchased online from 22 different sites was counterfeit. The author of the study, Irwin Goldstein, M.D., conducted the survey in cooperation with the global security arm of Pfizer, Viagra’s manufacturer.

So, caveat emptor, or buyer beware, is the name of the game. Place no order with an online pharmacy until you’ve thoroughly researched its operations and sponsorship. Be sure you’re dealing with a drug supplier that’s not only based in the United States but is also sourcing the medications it sells through U.S.-licensed pharmacies.