ClinicalTrials.gov is an online resource that provides information about clinical studies on a wide range of diseases. It includes information on whether the studies are recruiting patients, and a summary of the results of studies once they have finished.
The resource can be found at https://clinicaltrials.gov (address correct November, 2015).
Studies can be searched for by disease or by country. Although it is funded by the US government, it includes studies based around the world. The resource is aimed at patients and their families, healthcare professionals, researchers and the public. The website is maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH).