Two classes of medications work directly on the pituitary tumor to suppress GH secretion: dopaminergic agonists (e.g. cabergoline) and somatostatin receptor ligands (e.g. octreotide, lanreotide, pasireotide), while pegvisomant as a GH receptor antagonist lowers IGF-I by blocking GH action. Here, GH1 is linked to pituitary tumor.