The Food and Drug Administration (FDA) is launching a new campaign to warn consumers to avoid buying medicine from fraudulent online pharmacies.

The National Association of Boards of Pharmacy estimates that less than 3 percent of online pharmacies meet state and federal laws.

The campaign, called "BeSafeRx: Know Your Online Pharmacy," explains that drugs purchased from rogue online pharmacies can pose a serious risk, because they may contain too much or too little active ingredient, CNN reports.

These drugs may contain the wrong ingredients, or have no active ingredients.

The FDA recommends that patients only buy prescription drugs online through pharmacies that are located in the United States, require a valid prescription from a doctor or healthcare professional, provide a licensed pharmacist for consultation, and are licensed by the patient's state board of pharmacy.

"Buying medicines from rogue online pharmacies can be risky because they may sell fake, expired, contaminated, not approved by FDA, or otherwise unsafe products that are dangerous to patients," FDA Commissioner Dr. Margaret Hamburg said in a news release. "Fraudulent and illegal online pharmacies often offer deeply discounted products. If the low prices seem too good to be true, they probably are. FDA's BeSafeRx campaign is designed to help patients learn how to avoid these risks."

A survey by the FDA found about one-fourth of consumers purchased prescription drugs online, but almost 30 percent said they were not confident about buying drugs safely on the Internet.