Cabergoline 0.5 mg is the medication used to treat the body's overabundance of prolactin hormone. Excess prolactin can cause symptoms including irregular periods and unwanted breast milk, as well as make it more difficult for women to conceive. Symptoms of elevated prolactin levels in men can include bigger breasts and decreased desire or libido. An ergot medication called cabogoline 0.5 mg prevents the pituitary gland from releasing prolactin.