Using time resolved neutron scattering (TR-SANS) and isotope labeling, we previously showed that almost all of the investigated natural AMPs significantly increase the inter-vesicle lipid exchange, as well as the intra-vesicle lipid flip-flop . This would likely lead to scrambling of the membrane, which by itself could be detrimental for the cell. However, it was hypothesized that the lipid flipping could carry counter ions across the membrane, or even open short-lived transient pores, which could potentially explain the observed permeabilization. In support of the latter, we showed that atomistic molecular dynamics (MD) simulations could faithfully reproduce the observed membrane structure and indolicidin insertion, revealing that the AMP-induced lipid flipping created transient water-filled channels . Together, these structural and permeability studies support the non-poreforming mechanism of these AMPs and align with Wimley's interfacial activity model, as well as the lipocentric model presented by Fuertes et al . However, significant limitations remain. Primarily, permeabilization studies have relied on large fluorescent dyes, which, while informative, do not directly correlate to the permeability of monoatomic ions. Smaller ions likely permeate at faster timescales and potentially lower peptide-to-lipid (PL) ratios. While ion permeability has been assessed in prestene bilayers using radioactive tracers , or 31 P-NMR combined with Mn 2+ quenching in the case of melittin permeabilized membranes, these methods lack the temporal resolution to follow sub-second kinetics. Furthermore, structural characterization and permeability assessments have been conducted separately, making it challenging to compare findings and discern molecular mechanisms.