How is pegvisomant different from other acromegaly drugs?

It blocks the growth hormone receptor rather than lowering GH secretion, so it directly reduces IGF-1. Serum GH can rise on treatment, so dosing is guided by IGF-1, not GH.

Why is liver monitoring needed?

Pegvisomant can cause reversible increases in liver transaminases, so periodic liver-function tests are recommended during treatment.

In the pivotal trial and long-term data it normalizes IGF-1 in the large majority of patients, including many resistant to somatostatin analogues.

Can it be combined with other treatments?

Yes. It is sometimes used with a long-acting somatostatin analogue for patients with only partial control, under specialist supervision.

EMA-approvedaka Somavert

Pegvisomant — Complete Research Guide (2026)

Last updated 2026-06-30

TL;DR

Pegvisomant (also known as Somavert) is a peptide catalogued under Hormones & Metabolic (GH receptor antagonist (PEGylated)). It is described as: GH receptor antagonist. Documented context: Acromegaly. Neutral reference entry; EU status: EU-approved prescription medicine.

What is Pegvisomant?

Pegvisomant (brand name Somavert) is a pegylated, genetically engineered analogue of human growth hormone that acts as a growth hormone-receptor antagonist. It is FDA- and EMA-approved for acromegaly in patients who have had an inadequate response to surgery, radiation, and/or other medical therapy.

Unlike agents that lower GH secretion, pegvisomant blocks GH action at the receptor and is dosed to normalize IGF-1.

Evidence comes from pivotal randomized trials and long-term registry data (ACROSTUDY).

How does Pegvisomant work?

Pegvisomant binds the growth hormone receptor but blocks the functional receptor dimerization needed for signal transduction, preventing IGF-1 generation.

Because it acts peripherally on GH action rather than pituitary GH secretion, serum GH may rise while IGF-1 falls, so treatment is titrated to IGF-1.

What does the research say about Pegvisomant?

Pegvisomant normalizes serum IGF-1 in the large majority of acromegaly patients, with response increasing at higher daily doses in the pivotal randomized trial. ^[1]
Efficacy is sustained with long-term daily use, achieving IGF-1 normalization in most treated patients over years of follow-up. ^[2]
It is a key option for acromegaly resistant to somatostatin analogues, including as add-on combination therapy. ^[5]

Clinical research & studies

The references below are the primary sources cited throughout this guide. Each links directly to PubMed or the regulator. Where evidence is preclinical (animal or in-vitro), that is stated rather than implied.

[1] Treatment of acromegaly with the growth hormone-receptor antagonist pegvisomant — Trainer PJ et al., New England Journal of Medicine 2000. (Randomized controlled trial)
[2] Long-term treatment of acromegaly with pegvisomant, a growth hormone receptor antagonist — van der Lely AJ et al., Lancet 2001. (Long-term open-label study)
[3] Long-term safety of pegvisomant in patients with acromegaly: comprehensive review of 1288 subjects in ACROSTUDY — van der Lely AJ et al., Journal of Clinical Endocrinology and Metabolism 2012. (Observational registry (n=1288))
[4] Quality of life in acromegalic patients during long-term somatostatin analog treatment with and without pegvisomant — Neggers SJ et al., Journal of Clinical Endocrinology and Metabolism 2008. (Clinical study)
[5] Approach to the Patient With Treatment-resistant Acromegaly — Coopmans EC et al., Journal of Clinical Endocrinology and Metabolism 2022. (Clinical review)

Dosing context

This is not medical advice or a usage recommendation. Dosing figures are reported research context only, cited from the published literature.

In labeled use, pegvisomant is given as a daily subcutaneous injection, typically started after a loading dose and then titrated against IGF-1 rather than by symptoms alone.

Any doses mentioned are context only; this is a specialist-managed prescription medicine and nothing here is dosing guidance.

Side effects & safety profile

Pegvisomant requires periodic liver-enzyme (transaminase) monitoring because reversible elevations of hepatic transaminases can occur, occasionally requiring dose adjustment or discontinuation.

Long-term ACROSTUDY surveillance supported an overall favorable safety profile but reaffirmed the need for liver-function monitoring and periodic pituitary MRI to watch for tumor growth.

Injection-site reactions (including lipohypertrophy) and headache are reported; it is prescription-only and managed by specialists.

Stacking & combinations

In clinical practice pegvisomant is sometimes combined with a long-acting somatostatin analogue for patients with partial response, an approach studied in acromegaly management.

Finding Pegvisomant vendors

This is an independent, neutral directory — we sell nothing and route no purchases. Use it to read regulatory context and (where available) genuine, moderated vendor information for your country.

Choose your country

We never list placeholder vendors. Pick your country to see neutral regulatory context.

Browse the directory

User reviews

No reviews yet

Reviews appear here once submitted and moderated. An aggregate rating is shown only after at least 5 genuine reviews — we never fabricate ratings.

Frequently asked questions

Acromegaly in patients with an inadequate response to surgery, radiation therapy, and/or other medical therapy. It is FDA- and EMA-approved and prescription-only.

References

[1] Treatment of acromegaly with the growth hormone-receptor antagonist pegvisomant — Trainer PJ et al., New England Journal of Medicine 2000. PMID: 10770982. View sourceStudy: Randomized controlled trialPegvisomant produced dose-dependent normalization of IGF-1 in most acromegaly patients over 12 weeks, establishing GH-receptor antagonism as effective therapy.
[2] Long-term treatment of acromegaly with pegvisomant, a growth hormone receptor antagonist — van der Lely AJ et al., Lancet 2001. PMID: 11734231. View sourceStudy: Long-term open-label studySustained daily pegvisomant normalized IGF-1 in the large majority of patients over prolonged treatment, with reversible transaminase elevations noted.
[3] Long-term safety of pegvisomant in patients with acromegaly: comprehensive review of 1288 subjects in ACROSTUDY — van der Lely AJ et al., Journal of Clinical Endocrinology and Metabolism 2012. PMID: 22362824. View sourceStudy: Observational registry (n=1288)Long-term real-world data supported an acceptable safety profile while confirming the need to monitor liver enzymes and pituitary tumor size.
[4] Quality of life in acromegalic patients during long-term somatostatin analog treatment with and without pegvisomant — Neggers SJ et al., Journal of Clinical Endocrinology and Metabolism 2008. PMID: 18647806. View sourceStudy: Clinical studyAdding pegvisomant to somatostatin-analogue therapy improved IGF-1 control and quality of life in patients not fully controlled on monotherapy.
[5] Approach to the Patient With Treatment-resistant Acromegaly — Coopmans EC et al., Journal of Clinical Endocrinology and Metabolism 2022. PMID: 35090028. View sourceStudy: Clinical reviewReviews management of acromegaly resistant to first-line therapy, positioning pegvisomant (alone or in combination) as an effective option for normalizing IGF-1.

This article is for educational and research purposes only. Peptides discussed here are not approved for human consumption by the FDA, EMA, or equivalent regulators outside of specific clinical contexts. Always consult a licensed medical professional before any therapeutic use.