Why try to develop new drugs and therapies when we can repurpose old ones? Atul J. Butte, MD, PhD, Chief of Division of Systems Medicine at Stanford School of Medicine relays what happened when a cardiac drug showed unexpected sexual side effects. He explains that Contract Research Organizations (CROs) can be optimally used for experimentation, allowing healthcare providers to not only find new drugs, but to find new uses for existing drugs, a field called drug repurposing. Read more about Atul J. Butte, MD, PhD. Filmed at Exponential Medicine, in February 2013, at Singularity University.