Colston et al. clarified the molecular mechanism by which salcaprozate sodium (SNAC) — the absorption enhancer in oral semaglutide (Rybelsus) — lets peptides cross the gut epithelium. They show SNAC inserts into cell membranes and generates transient, fluid defects through which peptides like semaglutide slip. The work helps explain why oral semaglutide needs roughly 400 mg of SNAC for just 7–14 mg of peptide, and could inform next-generation oral peptide formulations beyond GLP-1s.