Breast cancer is the most commonly diagnosed cancer in women worldwide, and accounts for the largest number of cancer-related deaths in women. It is a highly variable disease that can manifest itself in a variety of ways. An important subtype is HER2-positive metastatic breast cancer. It is characterized by an overexpression of Human Epidermal Growth Factor Receptor 2 (HER2), a protein that interacts with signaling pathways leading to cell division and tumor growth. It is an aggressive disease that was initially difficult to treat and associated with a poor prognosis. With the development of therapies specifically targeting HER2, such as the antibodies trastuzumab and pertuzumab, significant advances have been made in the prognosis of patients with this form of breast cancer. For maximum responses, these targeted treatments are usually combined with chemotherapy. However, traditional chemotherapy is known for its many side effects such as nausea, hair loss, and a weakened immune system, causing a physically demanding and impactful treatment regimen. Despite successful treatment, a large proportion of patients develop resistance, and many face progressive deterioration of their disease.   Fortunately, the introduction of antibody-drug conjugates (ADC) has brought significant advancements in the treatment of HER-positive metastatic breast cancer. This new class of drugs combines the specificity of antibodies with the destructive properties of chemotherapy in one single molecule. The antibody has the ability to precisely identify the HER2 receptor, which allows the conjugated chemotherapeutic agent to be directly delivered into cancer cells. This benefit has led to significant enhancements in progression-free survival and overall survival for patients with HER2-positive metastatic breast cancer. Trastuzumab emtansine (T-DM1) was the first ADC approved by the FDA to treat patients who progressed under first-line treatment with dual anti-HER2 therapy plus chemotherapy. In 2019, a second ADC, trastuzumab deruxtecan (T-DXd), was approved to approach highly pretreated patients. Unlike other HER2-targeted therapies, T-DXd also achieved a potent response in tumors with low expression of HER2, making it the current recommended second-line treatment. With their targeted mechanism of action, ADCs spare the majority of healthy cells, unlike traditional chemotherapy, which reduces toxicity and optimizes efficacy. Previously harsh treatments are thus gradually being substituted by more patient-friendly options.   Due to their promising efficacy and favorable impact on serious side effects, ADCs may lead to shorter hospitalizations and the need for fewer healthcare providers in the treatment of this disease, reducing the burden on healthcare. Freeing up personnel and hospital beds could also ensure lower healthcare costs and better access to medical facilities, benefiting patients with other conditions and the broader public. The budget that this could free up in the long term, could be used to further invest in research into ADCs and to cover the high development and production costs of these drugs. This is relevant to the broader public, as it may contribute to the overall affordability and access to health care. Providing more outpatient care not only has economic benefits but may also have a positive impact on the patient's quality of life. The shorter hospital stays would enable patients to maintain their regular schedules and participate more fully in social and professional activities. HER2-positive metastatic breast cancer is a disease with a chronic course that requires long-term treatment. Antibody-drug conjugates can have a significant impact on both the demanding physical and emotional aspects of the disease by improving the patient's quality of life and prolonging their survival.   It is unfortunate that some patients also develop resistance to ADCs over time. Therefore, studying the mechanisms of resistance and finding ways to overcome it are essential for the long-term success of these treatments. Further research should focus on designing antibodies with higher HER2 specificity and maximizing the efficacy of linkers. In particular, membrane-permeable chemotherapeutic agents and cleavable linkers could cover most of the patient population, including patients with low expression of HER2. The more companies invest in the development and research of this therapy, the better we can understand the current shortcomings and improve ADCs to overcome them. Research into the development of ADCs for the treatment of breast cancer can also lead to advances in other areas of medicine and science that will benefit society.   A potential future application of ADCs is in the field of personalized medicine. As we gain a better understanding of the unique genetic and molecular tumor profiles of individual patients, we can design treatments to meet their specific needs. By making ADCs more accessible and widely incorporated into standard treatment plans, we have the opportunity to identify the best-fit treatment option for each individual patient with HER2-positive metastatic breast cancer.