The present disclosure provides granzyme-activatable and detectable membrane-interacting peptides that, following activation, can interact with phospholipid bilayers, such as cell membranes. The present disclosure also provides methods of use of such peptides, as well as compositions comprising such peptides. The peptides of the present disclosure are of the general structure X1a-A-X2-Z-X1b, where A is a membrane-interacting peptide region having a plurality of nonpolar hydrophobic amino acid residues that, following separation from portions Z, is capable of interaction with a phospholipid bilayer; Z is an inhibitory peptide region that can inhibit the activity of portion A; X2 is a granzyme-cleavable linker that can be cleaved to release cleavage products from the compound; and X1a and X1b are optionally-present chemical handles that facilitate conjugation of various cargo moieties to the compound.