Pegvisomant

FDA approved

Pegvisomant (Somavert) is a growth hormone receptor antagonist approved by the FDA in 2003 for acromegaly. It is the only approved drug that blocks growth hormone's action rather than its release.

At a glance

Where it acts: Hormones & metabolism
Regulatory status: FDA approvedApproved by the U.S. FDA for at least one medical use.

Mechanism of Action

Pegvisomant is a modified growth hormone molecule with several amino acid substitutions and attached PEG chains. It binds the growth hormone receptor but prevents it from activating, which lowers IGF-1 levels.

Typical Dosage (Research)

Prescription-only medicine. Dosing is set by a physician according to the FDA-approved label and the condition being treated.

Side Effects & Risks

Injection site reactions, liver enzyme elevations, flu-like symptoms and changes in fat at injection sites.

Liver test monitoring is required. Growth hormone levels rise, and the underlying pituitary tumor is not treated, so tumor size must be monitored. Can lower blood sugar in people with diabetes.

Who Uses Pegvisomant

Adults with acromegaly who have not responded adequately to surgery, radiation or other medicines.