Screening FDA-approved drugs accelerates drug discovery:· 100% known bioactivity· Greatest degree of drug-likeness available· Known safety & bioavailability· Accelerates drug optimizationDrug repositioning or repurposing can be an important part of any drug discovery program and has led to several blockbuster drugs (e.g. Viagra and Rogaine). High-content screens, new biomarkers and noninvasive imaging techniques have created new opportunities for pursuing novel indications for approved compounds. Being FDA approved and in use in the clinics, all of the compounds in Screen-Well™ FDA Approved Drug Library have known and well-characterized bioactivity, safety and bioavailability - properties which could dramatically accelerate drug development and optimization. The library also avoids irrelevant compounds found in similar libraries, such as herbicides, insecticides, sunscreen agents, and cytotoxic agents. This set provides one of the richest sources of bioactives and offers the greatest degree of drug-likeness available. Hits from this set will provide a significant head start in any drug optimization program.