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

Somatrogon (Ngenla, somatrogon-ghla): what the evidence says

Name: Somatrogon (Ngenla, somatrogon-ghla)
Published: 2026-10-27

At a glance

What it is: human growth hormone fused to extra copies of a short peptide (the C-terminal peptide, CTP) from the beta chain of hCG, which slows its clearance so it can be given weekly. Approved as Ngenla (Jun 2023) for children 3 years and older with growth failure from GH deficiency. ^{R1, R2}

What the evidence says: Human in a phase 3 trial of 224 children, weekly somatrogon was non-inferior to daily somatropin for growth at 12 months. ^R3 In adults, a phase 3 trial did not meet its main goal (trunk fat), though lean mass improved. ^R4

Biggest risks: label warnings match other growth hormone products: serious allergic reactions, possible tumor growth, glucose intolerance, raised pressure in the skull and others. Prohibited in sport. ^{R2, R5}

Rating


Human Human evidence	Strong: phase 3 RCT in children (n = 224) ^R3
Animal Animal / lab evidence	Not reviewed
Regulatory	FDA-approved ^R1 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R6, R7, R8} · prohibited at all times (WADA S2.2.3) ^R5
Established human dose	Yes, label dose (see Study details)

Evidence verdict: Child growth hormone deficiency: Strong (phase 3 RCT) · Adult growth hormone deficiency: not approved in the US (phase 3 missed its main goal) · Anti-aging or bodybuilding: 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: open-label sponsor RCT against daily GH; adult data are negative on the primary endpoint.

What is it?

Does it work?

Human Children (12 months): height velocity 10.10 vs 9.78 cm/year with daily somatropin; non-inferior. ^{R3, R9}
Human Adults: trunk fat change −0.37 vs +0.03 kg with placebo, not significant; lean mass improved. Not approved for adults in the US. ^{R4, R2}
⚪ Anti-aging or bodybuilding: no human data.

Is it safe?

Label warnings: severe hypersensitivity, neoplasms, glucose intolerance, intracranial hypertension, and others shared with somatropin. ^R2
Human Adverse events in the child trial were mostly mild to moderate and similar to daily GH. ^R3

Gray-market vials: 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: FDA-approved, prescription (Ngenla), for children only. ^{R1, R2}
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R6, R7, R8}
Sport: prohibited at all times; WADA names somatrogon under S2.2.3. ^R5

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
Deal 2022 (phase 3)	224 prepubertal children with GHD	SC	0.66 mg/kg/week vs somatropin 0.24 mg/kg/week	12 months	Height velocity 10.10 vs 9.78 cm/yr	PMID 35405011
Fleseriu 2026 (phase 3)	198 adults with GHD	SC	Weekly, per study	26 weeks double-blind	Trunk fat −0.37 vs +0.03 kg (not significant)	PMID 41879875

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Drugs@FDA, Ngenla (somatrogon-ghla), application BLA761184 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=BLA761184
^R2 Ngenla prescribing information, label published Aug 19, 2026 (DailyMed, checked Oct 27, 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=06dce529-b741-4a1b-8842-3ad77be6e308
^R3 Deal CL, et al. J Clin Endocrinol Metab. 2022. PMID 35405011
^R4 Fleseriu M, et al. Pituitary. 2026. PMID 41879875
^R5 WADA. The 2026 Prohibited List, S2.2.3, Growth hormone (GH), its analogues and fragments, naming somatrogon. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R6 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R7 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R8 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
^R9 ClinicalTrials.gov NCT02968004, phase 3 in children with GH deficiency (MOD-4023), completed, 224 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT02968004

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Somatrogon (Ngenla, somatrogon-ghla). This is a prescription medicine. Use it only under the care of a licensed clinician; do not buy it from research-chemical or gray-market sellers. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).