Ralinepag is primarily used in the treatment of pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries of the lungs. It functions as a prostacyclin receptor agonist, helping to dilate blood vessels and reduce the strain on the heart by improving blood flow. This medication is particularly beneficial for patients who require long-term management of PAH, as it helps to alleviate symptoms such as shortness of breath, fatigue, and chest pain. By targeting the underlying mechanisms of the disease, Ralinepag plays a crucial role in enhancing the quality of life and potentially improving the prognosis for individuals with this chronic condition.