In comparison to exit rates, the derivation of ligand entry rates in MD is not trivial, with multiple reported approaches optimized for different cases of protein-ligand binding . When it comes to the explicit kinetic analyses of monomer entry into a lipid assembly (Figure , Supp. Video 2), the available literature is rather scant . To accommodate this challenge, we adapted published algorithms in the realm of protein-ligand binding to fit the lipid assembly system. We defined the term "addition time", which is the duration between two consecutive entries of lipids of the same type. In this approach, the cluster into which the probe lipid enters includes the lipid that entered prior to it. Our defined "addition time" is analogous to the unbound time in ligand-protein systems , a duration in which a receptor is not bound to a ligand. It has been argued that the unbound time of a receptor, together with the concentration of free ligands, correspond to the entry rate coefficient. We therefore use the formula shown in eq. 2, whereby ⟨𝐶 𝑚𝑜𝑛𝑜𝑚𝑒𝑟𝑠 ⟩ is the average of the varying concentration of free probe during the addition time. In the analysis, we only inspected residence reactions that occurred for more than 300ps in clusters of at least ten monomers.