Macroprolactinemia, defined as hyperprolactinemia with a predominance of the big big prolactin (macroprolactin) isoform, is considered idiopathic and poorly symptomatic. Although macroprolactinemia has been considered to be a cause of apparent resistance to antiprolactinemic drugs, prolactin (PRL) normalization with dopaminergic treatment cannot exclude macroprolactinemia. We report three cases with macroprolactinemia, whose PRL and macroprolactin levels were decreased and hyperprolactinemic symptoms were improved with dopamine agonists
