Wikipedia may be wildly inaccurate but at least it isn't dangerous. For really dangerous advice, the assumption has been to go on Internet health forums. 

Faint praise, but a new analysis suggests that medical advice given on Internet health forums may be of better quality than people tend to assume. They focused on three popular online discussion forum websites - reddit, mumsnet and Patient.

The researchers, graduate student Jennifer Cole, Dr. Chris Watkins and Dr. Dorothea Kleine, from Royal Holloway, asked doctors and members of the public to rate information which had been given in response to questions relating to diabetes, HIV and chickenpox. The results showed that the ratings were mostly favorable, and even where information was considered to be inaccurate, this did not automatically mean tthe advice given was bad.  There were few examples of really inaccurate, dangerous Joe Mercola information. So it was instead more of the Gwyneth Paltrow/Shailene Woodley kind.

The NHS and many medical charities are still very reluctant to support or enable Internet discussion forums where patients are able to discuss medical symptoms or diagnoses. The researchers say there appears to be a perception that such forums will contain inaccurate information or advice that may be harmful to those reading it.

However Cole says, “In reality, forums such as reddit have very responsible posting policies, verifying the qualifications of posters who claim to be medical professionals, separating medical discussion forums from alternate therapy discussions, swiftly removing incorrect or potentially harmful information and encouraging posters to seek professional healthcare.”

Rowan Davies, Head of Policy and Campaigns at Mumsnet, told the researchers that he did not know of a single case where anyone had come to harm because of poor quality information they had read on Mumsnet, and that “inaccurate information is dealt with on-thread by posters themselves, who will usually challenge it and post up alternative points of view. We think it's rare for incorrect or out-of-date information to go unchallenged.”

Citation: Jennifer Cole, Chris Watkins, Dorothea Kleine, Health Advice from Internet Discussion Forums: How Bad Is Dangerous? Journal of Medical Internet Research 06.01.16 in Vol 18, No 1 (2016): January