Professor Craik is a biological chemist who has made important discoveries in the field of structural biology, particularly in the structural elucidation of peptide toxins and proteins having novel topologies. He discovered the cyclotide family of circular knotted proteins and, more generally, has pioneered the field of circular proteins. Circular proteins are characterised by their exceptional stability and professor Craik’s studies have led to their application in drug design and agriculture. His development of an orally active peptide for the treatment of pain is a paradigm-shifting example that has the potential to broadly expand applications of peptides as drugs.