The advancement of medical care depends to a large extent on the production of new knowledge, and for studies on the efficacy of drug treatments, this in turn depends mostly on randomized controlled trials. To make informed decisions about the risks and benefits of our available drug therapy options, we need trials that compare alternative ways of treating patients. But trials are expensive to conduct. Even modestly sized trials can easily run over a $1 million to plan, conduct, and analyze. Bigger trials, looking for smaller effect sizes or longer-term outcomes or comparing multiple different treatments, will cost more—potentially much, much more.