[1] D2 receptor agonists that are described as prolactin inhibitors include the approved medications bromocriptine, cabergoline, lisuride, metergoline, pergolide, quinagolide, and terguride and the never-marketed agent lergotrile.

[3] Other dopamine agonists and dopaminergic agents, for instance levodopa (L-DOPA), can also inhibit prolactin secretion.

[2] When such drugs are used not for the purpose of inducing prolactin secretion, increased prolactin levels may be unwanted, and can result in various side effects including mammoplasia (breast enlargement), mastodynia (breast pain/tenderness), galactorrhea (inappropriate or excessive milk production/secretion), gynecomastia (breast development in males), hypogonadism (low sex hormone levels), amenorrhea (cessation of menstrual cycles), reversible infertility, and sexual dysfunction.

Indirect dopaminergic agents such as levodopa can also suppress prolactin levels.

Other prolactin releasers besides D2 receptor antagonists include estrogens (e.g., estradiol), progestogens (e.g., progesterone), thyrotropin-releasing hormone and analogues (e.g., protirelin, taltirelin), and vasoactive intestinal peptide.