HyperfunctionBaseline serum prolactin > 250 ng / dl: prolactinoma, exclude drugs (risperidone, sulpiride, haloperidol, metoclopramide, etc.) > 500 ng / dl: macroprolactinoma <100 ng / dl and macroadenoma (hook effect): sample dilution 1: 100 Polyethylene glycol (macroprolactin) precipitation: in hyperprolactinemia asymptomaticHypofunctionBaseline serum prolactin: low. Here, PRL is linked to hyperprolactinemia.