During the last century the conjunction of chemistry, medicine and latterly recombinant DNA technology, was responsible for driving the widespread development of chemicals as pharmaceutical drugs. The development of biologicals (manufactured by cell fermentation) was much slower, and had to await the advent of recombinant DNA technology, and in the case of antibodies, of hybridoma technology. Antibodies have since become established as the paramount biological, particularly for the treatment of cancer and autoimmune disease. Even as the application of antibodies expands, biological selection technologies are leading to new drug platforms capable of creating tiny antibody mimics based on peptides. Will such developments spark another wave of innovative medicines based on peptides?