For more than 100 years, scientists have pursued the idea of delivering insulin as a pill. This goal has remained difficult to achieve because insulin breaks down in the digestive system and the intestine lacks a natural transport pathway that allows the hormone to enter the bloodstream.

Because of these biological barriers, many people with diabetes still depend on daily insulin injections, which can place a significant burden on long-term treatment and quality of life.

Researchers at Kumamoto University, led by Associate Professor Shingo Ito, have now developed a promising drug delivery strategy designed to overcome these obstacles. Their approach uses a cyclic peptide that can pass through the small intestine. The molecule, called the DNP peptide, helps insulin move across the intestinal barrier and into the body after oral administration.