Alzheimer’s disease (AD) is a serious kind of pathology that mainly affects older adults and significantly reduces the quality of their life. Despite decades of research, the pathogenesis of AD, the causes and the trigger mechanism of its occurrence remain the subject of debate. This review examines hypotheses of the pathogenesis of AD, including the involvement of amyloid-β peptide and hyperphosphorylated tau protein fragments in neuroinflammation and neurodegeneration. It also discusses potential therapies for AD based on peptides that target various aspects of the disease’s pathogenesis.