The current internationally accepted treatment for pituitary prolactin adenoma is drug therapy of choice, but bromocriptine can reduce prolactin (PRL) levels in many patients with prolactinoma, but it is not possible to reduce prolactin levels in all patients with prolactinoma. It is advisable to use a bromocriptine sensitivity test prior to drug treatment to confirm which patients are suitable for oral treatment with bromocriptine. The test is performed as follows: prior to systemic administration of bromocriptine, a single oral dose (2.5 mg) of bromocriptine is given to the patient to be tested, and blood PRL values are measured 2, 4, 6 and 8 hours after administration of the drug, compared to the PRL values of the patient without the drug. If the PRL value at each time point does not decrease after taking bromocriptine, the patient is not suitable for oral treatment with bromocriptine and other treatment modalities are available; if the patient’s PRL can decrease to less than 50% of the blank control at each time point after taking the drug, the patient is considered sensitive to the drug and suitable for treatment with bromocriptine. The bromocriptan sensitivity test allows the screening of patients with lactosarcoma suitable for oral drug treatment and the development of specific treatment plans based on changes in PRL values during subsequent observation and treatment.