Because biopharmaceuticals are medium- and high-molecular-weight, biologically active macromolecules, they are not easily absorbed by the small intestine, resulting in a bottleneck for oral administration. Now, researchers from Kumamoto University in Japan have found a new, small-intestine-permeable peptide that can facilitate digestive tract absorption of biopharmaceutical products. The discovery is expected to contribute greatly to the development of orally administered drugs for medications that are currently only available by injection, including widely used biopharmaceuticals such as insulin.