KDC-MN-086 – Kodiac biolabs

Plain-language summaryIntrigue 50 / 100

HGH Fragment 176-191 is the natural C-terminal fragment of human growth hormone (the parent peptide of AOD-9604). It is hypothesized to drive selective fat loss without affecting blood sugar or causing the systemic effects of full growth hormone. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Our opinion on this compoundEstablished workhorse

53/100

The canonical GH axis reference standard, evidence-rich but offering minimal research novelty in 2026

Look, somatropin is one of the most thoroughly characterized protein drugs ever made. Approved since 1987, studied in tens of thousands of patients across pediatric GHD, Turner syndrome, Prader-Willi, HIV wasting, short bowel syndrome, and adult GHD. The evidence base here is genuinely massive. If you need a clean, well-replicated signal that something is biologically real and clinically durable, somatropin delivers it. Thats not in dispute.

The problem, from a research library standpoint, is that the compound is almost completely understood. Receptor dimerization at GHR, JAK2 activation, STAT5 phosphorylation, hepatic IGF-1 synthesis, IGFBP-3 ternary complex assembly. This is the kind of biology you teach in first-year endocrinology. The mechanism is not novel, the axis is not under-explored, and the pharmacology is saturated. What we like about HGH is precisely the thing that makes it a poor research target: it is entirely legible. You already know what it does.

We also have to be honest about where the interesting work lives right now. Investigators pushing GH axis biology are mostly working on GHRH analogs (tesamorelin, CJC-1295), ghrelin-mimetic GHRPs (ipamorelin, hexarelin), small-molecule secretagogues like MK-677, or long-acting somatropin conjugates like somapacitan and lonapegsomatropin. The secretagogue literature is livelier than direct GH replacement, partly because preserving pulsatility matters and partly because the regulatory and sourcing landscape for secretagogues is more tractable at bench scale. Full-length recombinant GH is also expensive, cold-chain-dependent, and immunogenic in some preparations. These arent disqualifying issues, but they complicate the research workflow relative to a clean synthetic peptide.

Where somatropin still earns real points is bench utility and translational weight. If you’re doing mechanistic work on the GH/IGF-1 axis, it remains the gold standard reference. Any study that needs to compare a secretagogue’s IGF-1 response against direct GH replacement needs somatropin. The approvals also mean the pharmacokinetic and safety dataset is irreplaceable for comparative work. We don’t want to understate that. But as a primary research target, a compound this well-characterized really does belong in a support role rather than at the frontier. The field moved on. The interesting questions about GH biology now orbit around tissue selectivity, pulsatility engineering, and combinations with GLP-1 axis agents. Somatropin is the baseline you measure from, not the thing you’re running toward.

Novelty: 18
Mechanism promise: 32
In-category differentiation: 58
Evidence quality: 85
Translational signal: 82
Research bench value: 65

Rationale Somatropin scores very high on evidence quality and translational signal because it IS the approved drug with decades of phase 3 data, but novelty and mechanism scores drag the composite down hard; the GH/IGF-1/JAK2-STAT5 axis is textbook endocrinology, and the interesting frontier work has migrated to secretagogues, long-acting analogs, and downstream IGF-1 axis modulators rather than exogenous full-length GH replacement itself.

C-terminal hGH fragment

The unmodified C-terminal fragment of hGH (residues 176-191) sold as a research chemical for lipolytic applications.

Abstract

hGH Fragment 176-191 is the unmodified C-terminal 16-residue sequence of human growth hormone (Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe with a disulfide bond). The compound is a precursor to AOD-9604 (which adds a tyrosine N-terminal extension) and is sold as a research chemical with similar lipolytic claims. The mechanistic and clinical evidence base is essentially the same as for AOD-9604. The compound is not approved by any regulatory authority. Research-grade vendor doses are typically 250 to 500 micrograms subcutaneously daily.

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The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

Tag: KDC-MN-086

hGH Fragment 176-191

Abstract

Read the full monograph