DODAP (1,2-Dioleoyloxy-3-(dimethylamino)propane) is an ionizable cationic lipid widely used in lipid nanoparticle (LNP) formulations for nucleic acid delivery. Its amphiphilic structure includes hydrophobic oleoyl chains and a tertiary amine headgroup that becomes positively charged in acidic environments, such as endosomes. This pH-dependent ionization enables DODAP to destabilize endosomal membranes, facilitating the release of mRNA, siRNA, or DNA into the cytoplasm. DODAP’s ability to form stable nanostructures and its relatively low cytotoxicity make it a valuable component in LNPs, especially for applications requiring efficient intracellular delivery and minimal toxicity.