David S. Riley's interest in the history, methodology, and results of homeopathic drug provings came from his study of homeopathy at the Hahnemann College of Homeopathy in Albany, California. The 69 drug homeopathic drug provings published here are the result of his investigation of the research methods of homeopathic drug provings that form part of the basis for prescribing in homeopathy. In Dr. Hahnemann's time the method by which the treatment profiles of homeopathic remedies were determined was called provings, after the original German word Prufung, which means "test." Scientific research methods have evolved from the early days of homeopathy and Dr. Riley, in an attempt to improve transparency and reduce bias, has incorporated elements of contemporary research methods such as randomization, blinding, and formal good clinical practice guidelines (GCP) into homeopathic drug provings, while adhering to the general guidelines suggested by Dr. Hahnemann and used by homeopathic practitioners and researchers around the world.