Why does dostinex (cabergoline) causes acne?

Very unlikely: Hi. Your gender is not stated. I've been prescribing cabergoline (Dostinex) for a long time for hyperprolactinemia, and acne's not one of the side effects I see. If you're a man, you might also be being treated with testosterone for the hypogonadism caused by high prolactin, in which case it would be the testosterone causing the acne, not the Dostinex (if you're a woman, disregard that statement).