The main pathological features of Alzheimer’s disease (AD) include the cytotoxic extracellular accumulation of the amyloid beta (Aβ) plaques and intracellular neurofibrillary tangles. The Aβ plaques are responsible for cholinergic dysfunction and dementia in AD patients. Immunoglobulin G (IgG) and Aβ form an immune complex that activates neuroglia, clearing Aβ from the brain. Various Aβ-based therapeutic strategies have been proposed to reduce Aβ production, inhibit Aβ aggregation, and increase Aβ clearance. New medicines, such as aducanumab and donanemab, which are human IgG1 monoclonal antibodies, reduce cognitive impairment in patients with AD by decreasing the amount of Aβ plaques. Despite the considerable advantages of these agents, some disadvantages have also been reported, including Aβ-related imaging abnormalities, anaphylaxis, high cost, and contradictory results. Moreover, donanemab has delivered contradictory outcomes in improving recognition and performance in AD. However, although not fully proven yet, fewer side effects are reported for donanemab compared to aducanumab. Therefore, this review aims to explore the research background, compare the mechanism of action, and understand the advantages and disadvantages of aducanumab and donanemab. As a result, these medicines with maximum effectiveness and safety, yet fewer side effects, could be developed for future treatment and references.