Osilodrostat phosphate is primarily used in the treatment of Cushing's syndrome, a condition caused by excessive cortisol production in the body. It works by inhibiting the enzyme 11β-hydroxylase, which is crucial in the synthesis of cortisol in the adrenal glands. By blocking this enzyme, the drug effectively reduces cortisol levels, helping to alleviate symptoms such as weight gain, high blood pressure, and glucose intolerance. It is particularly beneficial for patients who are not suitable candidates for surgery or have not responded adequately to other treatments. The phosphate form enhances its solubility and bioavailability, making it more effective for oral administration. Clinical studies have shown its efficacy in normalizing cortisol levels and improving the overall quality of life for patients with this challenging condition.