HGH 191AA (Somatropin) is a growth peptides research compound currently in stock directly from a verified Chinese manufacturer. Every batch is HPLC-verified and shipped with a Certificate of Analysis (COA). Sourcing is direct — no intermediaries. Minimum order value is $600 USD. International shipping available.
HGH 191AA refers to recombinant human growth hormone (rhGH), also known as somatropin — a 191-amino acid single-chain protein that is the authentic sequence and structural equivalent of endogenous pituitary-derived growth hormone. The '191AA' designation reflects the complete 22 kDa isoform, which is the predominant circulating form of GH (approximately 75% of pituitary GH secretion). Recombinant somatropin is produced by heterologous expression in E. coli or mammalian cell systems using recombinant DNA technology, and the resulting protein — after purification and refolding — is structurally identical to native pituitary GH, including its two disulfide bonds (Cys-53/165 and Cys-182/189) and its tertiary four-helix bundle conformation. This structural fidelity is critical for full GH receptor (GHR) binding and activation.
GH's biological effects are mediated through two sequential pathways: direct GH receptor (GHR) activation producing acute metabolic effects (lipolysis, antagonism of insulin action, amino acid uptake in muscle), and indirect IGF-1-mediated anabolic effects (protein synthesis, cell proliferation, linear bone growth) via hepatic and local IGF-1 production. Research with recombinant GH (somatropin) is used to characterise both pathways across tissues, to establish reference pharmacokinetic and pharmacodynamic benchmarks for newer GH secretagogue compounds (sermorelin, tesamorelin, ipamorelin, CJC-1295), and to study GH receptor downstream signalling (JAK2/STAT5 pathway) in target cells. rhGH serves as the positive control in comparative studies of GH axis peptides.
PeptidesFromChina.co supplies HGH 191AA (somatropin) as lyophilized powder at ≥98% purity, verified by HPLC and confirmed by mass spectrometry. Certificates of Analysis available per batch. Wholesale quantities on request. For laboratory research use only.
| Chemical Class | Recombinant Human Growth Hormone (22 kDa isoform) |
|---|---|
| CAS Number | 12629-01-5 |
| Molecular Weight | 22,124 Da (22 kDa) |
| Sequence Length | 191 amino acids |
| Disulfide Bonds | Cys-53/Cys-165 and Cys-182/Cys-189 |
| Structure | Four-helix bundle (non-glycosylated) |
| Receptor Target | GHR (Growth Hormone Receptor) — JAK2/STAT5 signalling |
| Synonyms | Somatropin, rhGH, recombinant human GH, HGH |
| Storage | -20°C lyophilized; 2–8°C reconstituted (up to 14 days) |
| Molecular Formula | N/A — 191-aa protein; see COA |
| Name | Strength | Pack Size | Purity | Availability | Price (USD) |
|---|---|---|---|---|---|
| HGH 191AA (Somatropin) | 36 IU | 10 vials | ≥98% | In Stock | $200.00 |
Testing method: HPLC / LC-MS (["HPLC","LC-MS","Endotoxins","Sterility","Water Content","Assay"]). Every batch is tested before shipment. Purity ≥99% confirmed per batch.
Certificate of Analysis: Simple COA. Documentation is available for every batch sold.
GHR activation by somatropin recruits and activates JAK2 (Janus kinase 2), which phosphorylates STAT5a/b (Signal Transducer and Activator of Transcription 5). Phospho-STAT5 dimers translocate to the nucleus and drive transcription of IGF-1, acid labile subunit (ALS), and SOCS (Suppressors of Cytokine Signalling) genes. GHR-transfected cell lines (IM-9, 3T3-F442A) and primary hepatocytes are used to characterise JAK2/STAT5 phosphorylation kinetics, receptor internalisation, and SOCS feedback by Western blotting, phosphoproteomics, and STAT5 reporter assays. Somatropin is the reference agonist in all such studies.
Somatropin's dual metabolic role — direct lipolysis (via HSL activation in adipocytes) and indirect anabolic action (via IGF-1 in muscle and bone) — is characterised in rodent models of GH deficiency (hypophysectomised rats, lit/lit mice, dwarf rats) and in diet-induced obesity models. Body composition endpoints (lean mass, fat mass by DEXA or MRI) and metabolic endpoints (RQ, fatty acid oxidation, glucose turnover by isotope dilution) are used to quantify GH-mediated metabolic shifts. These preclinical datasets provide the reference pharmacodynamics against which GH secretagogue compounds (ipamorelin, tesamorelin, CJC-1295) are benchmarked.
GH and IGF-1 are the principal regulators of longitudinal bone growth at the growth plate (epiphyseal cartilage). In hypophysectomised rat growth plate models, somatropin restores chondrocyte proliferation (measured by BrdU incorporation), collagen II and X expression, and tibial growth plate width in a dose-dependent manner. IGF-1 ELISA in serum and liver provides the downstream hormonal endpoint. Local versus systemic GH effects are dissected using liver-specific IGF-1 knockout (LI-IGF-1-/-) mice, which distinguish hepatic IGF-1 from autocrine/paracrine IGF-1 production in skeletal tissue.
All preclinical and clinical evaluation of GH secretagogue peptides (GHRH analogues, GHRPs) uses exogenous somatropin as the positive control benchmark for GH-axis pharmacological effects. Comparative studies examine whether secretagogue-stimulated endogenous GH release produces equivalent downstream effects (IGF-1, IGFBP-3, bone markers, lean mass changes) at equivalent GH exposure levels as direct somatropin administration. This dose-equivalence methodology requires precise somatropin dose-response characterisation in each model system, making high-purity research-grade somatropin essential.
HGH 191AA (somatropin) is the complete 191-amino acid growth hormone sequence, activating the full GH receptor and downstream JAK2/STAT5/IGF-1 signalling cascade. It produces both growth-promoting (anabolic) and lipolytic effects. HGH Fragment 176-191 is a 16-amino acid C-terminal fragment that stimulates lipolysis without activating the GH receptor — it does not elevate IGF-1 or produce growth effects. They are used in research for opposite purposes: somatropin for full GH receptor studies and growth/metabolic phenotyping; HGH Fragment for selective adipose research without GHR activation.
Reconstitute lyophilized somatropin with sterile bacteriostatic water (0.9% benzyl alcohol) for multi-dose use, or with sterile water for single-use aliquots. Direct the diluent slowly down the vial wall; gently swirl rather than vortex to avoid protein denaturation. The reconstituted solution should be clear — turbidity indicates aggregation. Working concentrations in cell culture are typically 1–100 ng/mL. Reconstituted solution is stable at 2–8°C for up to 14 days. Avoid freezing reconstituted protein, as freeze-thaw cycles cause aggregation and loss of activity.
PeptidesFromChina.co supplies HGH 191AA at ≥98% purity by RP-HPLC. Identity is confirmed by ESI-MS. For protein-level characterisation, size-exclusion HPLC (SE-HPLC) is used to confirm monomer content (≥95% monomer, minimal dimer/aggregate) and SDS-PAGE under reducing conditions confirms the 22 kDa band corresponding to somatropin. Certificates of Analysis including HPLC chromatogram and mass spectrum are provided per batch.
Yes. HGH 191AA (somatropin) is available through PeptidesFromChina.co on a B2B wholesale basis. Pricing, vial sizes, and minimum order quantities are provided on request after account verification. Contact us via the Request page.
For laboratory research use only. Not for human or veterinary use. PeptidesFromChina.co is a B2B wholesale supplier operating under strict research-use-only terms. All products are sold exclusively for in vitro and preclinical research purposes.