PegvisomantGrowth-hormone receptor antagonist
Pegvisomant blocks growth-hormone receptor activity in acromegaly. Its action runs counter to the idea that all peptides stimulate growth or recovery.
What is Pegvisomant?
Pegvisomant is a modified growth-hormone protein used in acromegaly. It reduces the effects of excessive growth-hormone signalling rather than directly treating the pituitary tumour that produces the hormone. 1 2
How it works
It antagonises the growth-hormone receptor, lowering downstream IGF-1 production. IGF-1 is therefore central to monitoring its biochemical effect. 2
Effects studied
What does the evidence show?
Acromegaly treatment trials; archived prescribing information retained
Blocking the receiving end of the signal
Pegvisomant is a modified growth-hormone-related protein designed to antagonise the growth-hormone receptor. Instead of encouraging the pathway, it reduces its action. This can lower production of IGF-1, a key downstream mediator of growth-hormone excess.
The problem it addresses
In acromegaly, excessive growth-hormone signalling can affect tissues and multiple organ systems. Blocking the receptor offers a way to control that biological activity. It is different from removing a pituitary tumour or suppressing hormone secretion at its source, which may remain separate elements of care.
What a laboratory response means
Normalising IGF-1 is an important treatment target. However, a biochemical response should be discussed alongside symptoms, associated conditions and tumour surveillance. A treatment that blocks hormone action does not automatically demonstrate that the underlying pituitary lesion has shrunk or stopped changing.
Monitoring follows the mechanism
Liver-function abnormalities and injection-site effects need attention. Changes in insulin sensitivity can also affect the management of diabetes medicines. Pegvisomant therefore requires specialist care; it is not a general tool for changing body composition. Monitoring IGF-1 assesses the effect of receptor blockade, while continued pituitary follow-up addresses the source of the hormone excess.
Safety & status
Liver monitoring and injection-site effects are relevant. Changes in insulin sensitivity may affect diabetes treatment, and pituitary surveillance remains necessary. 2
Country and product status
Country-specific product availability and authorisation require a separate current check.
Frequently asked questions
Does it stop the tumour producing growth hormone?
Its main action is blocking the receptor response, not removing or directly suppressing the source tumour. 2
Why follow IGF-1 rather than just symptoms?
IGF-1 provides a biochemical measure of downstream growth-hormone activity, while symptoms and tumour status answer other questions. 2
Further reading
Sources
This entry was rewritten from our research archive. References below are reading leads unless a completed check is explicitly noted; a full independent evidence and regulatory review is still pending.
- Pegvisomant · retained archive reference Archive research lead · Retained archive reference; not independently checked for this draft
- Pegvisomant · retained archive reference Archive research lead · Retained archive reference; not independently checked for this draft
Research provenance
This name was discovered in the Superpower peptide index, archived 26 October 2026. Its ratings and reviewer attribution have not been adopted as our own. The archive informed this original editorial draft; independent source review is still pending.