Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Pegvisomant (Somavert): what the evidence says

Name: Pegvisomant (Somavert)
Published: 2026-10-27

At a glance

What it is: an FDA-approved, PEGylated 191-amino-acid growth hormone analogue that blocks the GH receptor. ^R1 Drugs@FDA now lists it as BLA 021106. ^R2

What the evidence says: in a 12-week RCT, IGF-1 normalized in up to 89% at the top dose vs 10% on placebo. ^R3 Long-term data in 160 patients and the ACROSTUDY registry support lasting control. ^{R4, R5}

Biggest risks: liver-enzyme rises (test liver function), low blood sugar in people with diabetes, and allergic reactions. ^R1

Rating


Human Human evidence	Strong: RCT ^R3; long-term studies ^{R4, R5}
Animal Animal / lab evidence	Not reviewed here
Regulatory	FDA-approved, BLA 021106 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page · not named on WADA's 2026 list ^{R2, R6, R7, R8, R9}
Established human dose	Labeled dosing only; see label ^R1

Evidence verdict: Acromegaly (normalizing IGF-1): Strong (FDA-approved, RCT and long-term registry) · Any other use: No human data

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: strong for acromegaly. GH levels rise on treatment, so IGF-1 is used to judge it. ^R4

What is it?

Pegvisomant is a modified growth hormone that sits on the GH receptor without switching it on. ^R1 Related pages: Human growth hormone, IGF-1 (mecasermin), Octreotide, Lanreotide.

Does it work?

Human RCT (n = 112): IGF-1 normalized in 54%, 81% and 89% across doses vs 10% on placebo; symptoms improved. ^R3
Human Long-term (n = 160): IGF-1 control maintained; GH antibodies in 16.9% without loss of effect. ^R4
Human ACROSTUDY (n = 1,288): long-term safety review. ^R5

Is it safe?

Human Two of 160 stopped for raised ALT/AST; two had tumor growth. ^R4
Human Label: hypoglycemia with diabetes drugs, liver toxicity monitoring, hypersensitivity. ^R1

Gray-market products: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: prescription biologic (BLA 021106). ^R2 not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R7, R8, R9}
Sport: not named on WADA's 2026 list. ^R6

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
RCT 2000	112 adults with acromegaly	SC daily	10, 15 or 20 mg	12 weeks	IGF-1 normal in up to 89%	PMID 10770982
Long-term 2001	160 adults	SC daily	Titrated	Mean 425 days	Lasting IGF-1 control	PMID 11734231

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 26, 2026)

^R1 Somavert prescribing information, label published Dec 18, 2025 (DailyMed, checked Oct 26, 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3cbb485b-6df1-49ce-8747-592b395b1988
^R2 Drugs@FDA, Somavert (pegvisomant), Pharmacia (Pfizer), approved Mar 25, 2003; listed as BLA, application BLA021106 (openFDA drugsfda record checked Oct 26, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=BLA021106
^R3 Trainer PJ, et al. N Engl J Med. 2000. PMID 10770982
^R4 van der Lely AJ, et al. Lancet. 2001. PMID 11734231
^R5 van der Lely AJ, et al. J Clin Endocrinol Metab. 2012. PMID 22362824
^R6 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R7 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R8 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R9 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Pegvisomant (Somavert). Pegvisomant blocks growth hormone. Talk to an endocrinologist. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).