Our work makes it clear that a low c* is not an indicator that a peptide system will form a self-supporting hydrogel network. In order to form a self-supporting hydrogel network in this P11 class of peptides, an overall magnitude of molecular charge of ~2 is required, which we hypothesise is due to the requirement of long-range repulsion between βfibrils favouring a well-hydrated open network of a self-supporting gel . Indeed, this conclusion is reinforced by the discovery that mixtures of oppositely charged peptides with a net average charge of magnitude 2 could also selfassemble into hydrogels, even though these peptides do not individually self-assemble or form gels. When comparing between peptide systems with a +2 or -2 charge, those with glutamine as the polar amino acid resulted in a lower c* and larger gel stiffness (G' and G") due to the additional hydrogen bonding interactions enhancing the cohesive energy of the structures . Similarly, the increased cohesive energy in the self-assembly of glutamine-rich peptides decreases the c* for self-assembly compared to serine-rich analogues .