A comprehensive site offering some full text articles, medical news, information for professionals and patients. Patient education information on a wide rang of topics including, heart disease, Tourette syndrome, sexually transmitted diseases. Published by the University of Iowa. A comprehensive guide to over 3,000 individual resources on mental health. The University of Pennsylvania's Cancer Center is an excellent resource for physicians and patients on the courses, diagnosis, current treatment protocols, support, clinical trials and more.
Registration is required, but it is free.
Excellent site maintained by the Tufts University School of Nutritional Science and Policy which rates nutritional sites and information.