Are there any selective growth hormone receptor blockers?

There is one: The only available member of this family is Pegvisomant (somavert). By blocking the action of the growth hormone molecules, this compound is able to control disease activity of acromegaly in virtually all patients.

Yes: There is a drug called Pegvisomant (somavert) that works by directly blocks the effects of growth hormone, and has been shown to improve symptoms of acromegaly. There are two other drugs that are less specific in binding but can also be used to treat acromegaly: bromocriptine and octreotide. These are highly specialized drugs that should be prescribed by a physician.