Review examines how oral peptide drugs cross the gut despite barriers

The wire

1. 01The Pharmaceutics review notes that typically less than 1% of an orally administered peptide therapeutic reaches systemic circulation, and catalogs the physiological factors that both block and permit uptake.
2. 02Formulators and clinicians tracking oral peptide programs get a framework for why bioavailability stays low and where transient paracellular transport may occur.
3. 03Transporter-mediated uptake of intact peptide drugs is judged unlikely because of substrate size limits; this is a narrative review, not new experimental data.

From the source

Natural Oral Absorption of Therapeutic Peptides: Mechanisms and Physiological Determinants

Pharmaceutics · 2026 Aug 29 · Ali Hussein L, Nedic A, Sitovs A et al.