In this study we use the Poisson-Boltzmann analysis in the Debye-Huckel limit to examine the effect of charge regulation on the interactions between similarly charged ion-penetrable adsorbed layers. We find that the magnitude of the interactions decays rapidly with the degree of charge regulation, although the decay length remains the Debye screening length. As a result, the interactions between charge-regulating layers are much weaker than those between strongly dissociated ones.