Over 60 million adults in the US are using social media applications for healthcare online, and many are speaking directly about products, according to a new Manhattan Research report.

Websites like iGuard.org, DailyStrength.org and PatientsLikeMe.com are garnering thousands of comments and reviews on drugs and treatments. On DailyStrength.org, over 9,000 consumers have written about Pfizer’s Zoloft, with comments ranging from side effects (“worked but gained a tremendous amount of weight!”), to off-label uses, such as pre-menstrual syndrome (“yes, this has been a help”).

Without clear guidelines from the FDA, manufactures will have to decide how best to monitor, solicit or respond to reviews and comments in these forums, the report said.

According to Craig Audit, vice president, US regulatory affairs, marketing products at Sanofi-Aventis, most adverse events reported on independent websites or on blogs don’t sufficiently identify the safety signals of a drug, and should not be submitted to the FDA. Each company must decide what actions mesh best with the prevailing corporate culture. “What’s your tolerance of uncertainty?” asked Audit at a conference on digital pharma in October.

Consumers commenting on products online is not all bad for manufacturers, since it provides unsolicited information to marketers, noted Alan Minsk, partner and chair of the food & drug practice team at Arnall Golden Gregory LLP, at the conference.