The aim of this study was to investigate the long-term controlled release of peptide-loaded fattigated albumin nanoparticles via calcium ion-triggering nanoaggregation with minimal initial burst release. Fattigated albumin nanoparticles were prepared via sonication by the self-assembly of human serum albumin (HSA)-oleic acid conjugates (AOC) with three different substitution ratios of oleic acid (OA) to modulate hydrophobicity. Then, pasireotide pamoate (PAS) as a model peptide was encapsulated into the hydrophobic core of HSA-OA nanoparticles (PAS-AONs). The critical micelle concentration of AOC decreased as OA substitution ratio increased. The loading efficiency of PAS increased owing to the strong hydrophobic-hydrophobic interactions between PAS and the hydrophobic block in the AONs. The release rate was also delayed, whereas the initial burst release was minimized, as the hydrophobicity of AOC increased. Interestingly, calcium ions triggered the formation of nanoaggregates of negatively charged PAS-AONs via electrostatic interactions, resulting in a further decrease in the release rate for one month via a reduced surface area while minimizing the initial burst release in a calcium ion concentration-dependent manner. The modulation of OA substitutions and calcium ion concentration of AONs could provide the potential for long-term delivery of peptide drugs while minimizing the initial huge burst release and controlling the release rate.