A commercial casein hydrolysate, which contains peptides RYLGY and AYFYPEL as active molecules, has shown antihypertensive effects after acute and long-term administration. This study examines transepithelial absorption of RYLGY and AYFYPEL and derived digestion fragments using Caco-2, HT29-MTX⁻⁶ and co-culture 75 % Caco-2/25 % HT29-MTX⁻⁶ as predictive models and RP-HPLC–MS as analytical tool. Peptides RYLGY and AYFYPEL were absorbed intact through cell monolayers, although RYLGY was partly hydrolyzed by intestinal peptidases. Co-culture 75 % Caco-2/25 % HT29-MTX⁻⁶ exhibited intermediate properties, with regard to transepithelial electrical resistance, peptide hydrolysis, and absorption of the studied peptides, between Caco-2 and HT29-MTX⁻⁶ pure cultures. Interestingly, mucus layer that covered completely HT29-MTX⁻⁶ and co-culture monolayers was not a barrier for the absorption of the studied peptides. The apparent permeability values for absorptive transport across Caco-2 monolayers for RYLGY (0.22 × 10⁻⁶ cm/s) and AYFYPEL (0.26 × 10⁻⁶ cm/s) were similar. These findings highlight that in vivo absorption of antihypertensive peptides RYLGY and AYFYPEL may occur partially as intact peptides.