U.S. consumers searching for cheaper drugs are willing to put aside safety concerns and buy from non-traditional, online pharmacies, a market research firm said Monday.

Fully 17.4 million Americans visited more than 3,000 traditional and non-traditional online pharmacies, located in the United States and abroad, in the fourth quarter of last year, a study by ComScore Networks Inc. found. That number represented a 14 percent increase from the previous quarter.

In addition, 63 percent, or 10.9 million, of the drug-seeking Americans visited non-traditional sites, an increase of 36 percent over the third quarter.

ComScore defines familiar companies like Walgreens.com and Drugstore.com as offering traditional pharmacy sites, while non-traditional would be sites that do not require an existing prescription.

Online drug purchases from both site categories are increasing steadily, with reducing the high cost of drugs in the United States a key factor driving consumers online, ComScore analyst Carolina Petrini said. Other factors include convenience, confidentiality and the ability to buy drugs without a prescription.

Combined, those factors have led many consumers to put aside concerns over the risk of buying drugs from an unknown supplier, or without visiting a doctor first.

"There''s certainly a level of danger in some of these practices," Petrini said. "(Nevertheless,) consumers have shown that they''re willing to take some risks."

The ComScore study, which was based on site traffic and a February survey of 315 consumers, found that more than half of the respondents said they were "very concerned" about the safety of drugs available online. Nevertheless, two-thirds of the consumers who bought drugs said they did so to reduce costs, and only 1 out of 3 were concerned about the lack of face-to-face communications with a pharmacist.

Without advocating any particular course of action, Petrini said the study indicates that drug manufacturers, healthcare professionals and government might need to consider educational campaigns that addressed safety and other related issues.

In other findings, nearly 4 out of 10 consumers said they would buy drugs online that are not approved by the Federal Drug Administration, if the medicines worked for them. A little more than half said the FDA should regulate all drugs consumed in the United States.

More than 6 out 10 consumers said some prescription drugs that have proven effective should be available to the public, despite secondary effects, as long as it was under direct supervision of a healthcare professional.

The study also found that physicians might not be aware of where their patients have obtained their drugs. Just more than 60 percent of the respondents did not inform their doctors of their last online-prescription purchase.

ComScore uses a quarter-to-quarter comparison in online drug buying, as opposed to year to year, because of the volatility of the market. Many online pharmacies operate for only a short time before they''re closed by government regulators or by court orders stemming from lawsuits filed by drug companies.

"(The pharmacies) come in and out of the radar screen frequently," Petrini said.