WebMD is launching a social networking platform, dubbed WebMD Health Exchange, aimed at giving users more control and connecting them with experts to talk about health issues in real time.

WebMD Exchange will feature expert-led communities but will also empower members to create their own communities, which can be public or limited to friends and family.

“We tried to gently structure that based on user input,” said EVP consumer services Nan Forte. “We wanted a structure that didn’t seem too rigid, but we had a responsibility to help people find their preference.”

Much of what’s new is in the customizability of the site. Before the redesign, WebMD couldn’t keep up with user requests to create new and ever more specific communities.

“People talk about the long tail of search,” says Forte. “Well, this is the long tail of social health networking, which is all about specificity and finding people like me. People who are starting their own are very specific: cancer patient who has heart disease and is a single mom. That becomes a community.”

The site’s architecture allows users to post in a variety of formats, from the Tweetesque Tips and Resources to longer-form Discussions and Experts.

Physicians from Duke Medicine will provide expertise to a number of communities, as will societies and advocacy groups including the National Health Council, the National Osteoporosis Foundation, the North American Menopause Society and the American Veterinary Medical Association.