Wikipedia:Training/core/Medical topics 2

Proper use of sources is critical, and the standards for sourcing on medical topics differ from other topic areas. In particular, the use of primary sources is more strongly discouraged.

By Wikipedia's conventions for medical content, typically inappropriate primary sources include reports of original medical research &mdash; such as clinical studies, case reports, or animal studies &mdash; even if published in respected journals. In general, medical and health-related content should be based on review articles from reputable journals and other professional medical literature. Popular press is generally not considered a reliable source for medical topics.

You should read the full guideline on identifying reliable medical sources.