Over the past 30 years there has been significant research into technologies that promote the delivery of high molecular weight, poor membrane-permeable compounds across the gut. Most work has concentrated on the delivery of peptides and proteins. However, technologies have also been applied to compounds such as poorly membrane-permeable small molecules, heparin and oligonucleotides. Much of this research has been characterized by early promise with many systems showing positive results in animal studies. Success in man has proven more elusive. In 2011, however, the oral delivery of peptides took one step closer to commercial reality when Tarsa Therapeutics announced that it had achieved positive Phase III data for oral recombinant salmon calcitonin. This article reviews the current development status of oral delivery systems for peptides and proteins and examines recent patent activity in this field based mainly on US patents issued in the last 2-3 years.