QualityHealth is a popular health website with more than 20 million registered users that offers online medical information and e-mail newsletters on a variety of topics, including diabetes, allergies, asthma and arthritis. But according to a complaint filed Tuesday with the Federal Trade Commission, site visitors who provide personal details about themselves might not be aware that QualityHealth collects information about people's medical conditions, preferred medicines and treatment plans and uses it to profile its users for prescription drug marketing. Rob Rebak, the chief executive of QualityHealth, a company also known as Marketing Technology Solutions of Delaware, did not return a request for comment. QualityHealth is one of a number of companies cited in the complaint to the FTC filed by four nonprofit privacy and consumer advocacy groups. In the complaint, the Center for Digital Democracy, U.S. PIRG, Consumer Watchdog and the World Privacy Forum charged that online marketing of medications, products and medical services posed fundamental new risks to consumer privacy and health because of sophisticated data collection and patient-profiling techniques. Asserting that such techniques are unfair and deceptive, the groups asked the FTC to investigate the health marketing used by some popular sites including Google, HealthCentral, Everyday Health, WebMD and Sermo, a site for medical professionals. Some sites, the complaint said, were not transparent enough about how they tracked people through users' online heath searches and discussions or how they categorized and marketed to their conditions. Other sites may not be entirely open about how they create and use data profiles about users or blur the line between independent and sponsored content, the complaint said. The concern, said Ed Mierzwinski, the consumer program director at U.S. PIRG, is not just about data mining and marketing that could influence patients to seek drugs they do not need or to spend more money on branded drugs rather than generics. More broadly, employers or health insurers could gain access to the consumers' data profiles, leading to potential problems or penalties against the consumer, he said. 'You could be searching for health information about your cat or your neighbor and it could end up harming your health care in terms of denial or increased cost,' Mierzwinski said. 'If people knew what kind of surveillance, eavesdropping and data mining were being used to collect information about you, encourage your use of prescription drugs and essentially use you as a research guinea pig, I think people would think twice.' The complaint comes at a delicate moment for online and social media marketing of medical products and services. The Food and Drug Administration, which oversees drug marketing, is developing industry guidelines for digital and social media. In a two-day agency hearing on the subject last winter, many health sites, drug makers and marketing firms promoted the idea of digital health as a tool that empowered consumers, allowing patients to easily access medical information and form supportive interactive communities with other patients. 'There are clear public health benefits for health care providers and patients to be able to access truthful, scientifically accurate and FDA-regulated information about medicines online from the companies that research and develop them,' said Jeffrey K. Francer, assistant general counsel of the Pharmaceutical Research and Manufacturers of America, an industry trade group. His group is still reviewing the complaint, he said. But Jeff Chester, the executive director of the Center for Digital Democracy, said that the industry had provided the FDA with a 'fairy-tale version of digital health marketing.' Online data collection techniques give 'pharmaceutical companies and health marketers a kind of digital X-ray of a health consumer's concerns, fears and behaviors,' Chester said. 'There is no meaningful disclosure of how that data is collected and used.' A notice at the bottom of QualityHealth's member registration form, for example, provides a link to the site's privacy policy. The policy explains that information that may or may not identify someone may be used for ads aimed at consumers. But QualityHealth provides greater detail about its methods in its pitch to business clients -- like how the site uses tailored messages, informed by patient profiling, to prompt members to seek prescriptions for specific brands from their doctors. 'We can reach consumers just before their next doctor visit,' the site says, 'as well as follow up with reminders and relevant information, for maximum impact.' The site's privacy policy states that the company is committed to providing consumers with clear notice and choice about its practices and that visitors are asked to opt in to the company's data use policy. Adam Grossberg, a spokesman for WebMD, said that WebMD had always been transparent and direct with its users. 'All sponsored content on our site is clearly labeled as such, he said.' He added that the company could not comment on the specifics of the complaint because it had not received it. A spokesman for Google said the company declined to comment for this article. HealthCentral, Everyday Health and Sermo did not respond to requests for comment. The groups decided to file their complaint with the FTC, Chester said, because it oversees consumer privacy issues and because, the groups believed that the FDA, which has long overseen traditional marketing of drugs in print, radio and television, lacked the staff and the expertise to oversee online and social media drug marketing. An FDA spokeswoman said the agency planned to review the complaint. David Vladeck, the director of the FTC's bureau on consumer protection, said he had not yet read the complaint. But, he said, the FTC plans to soon release a report about online privacy because it is concerned about sensitive personal information. Vladeck offered a hypothetical example of a core privacy question. 'Suppose someone goes online to read about depression, should that person get targeted with ads for antidepressants, for counseling services or books about depression?' 