HGH 191AA

HGH 191AA (Somatropin) 10 IU lyophilized is the full 191-amino-acid sequence of recombinant human growth hormone. The peptide is supplied as high-purity lyophilized powder (≥99% HPLC) in 10 IU vials and supports research into anabolic, lipolytic, and regenerative effects along the somatotropic axis. Strictly for research and laboratory use (RUO).

What is HGH 191AA?

HGH 191AA is the complete amino-acid chain of human growth hormone, comprising 191 residues with a molecular weight of approximately 22.1 kDa. Recombinant expression in a bacterial system delivers the native primary structure with the canonical disulfide bridges between Cys53-Cys165 and Cys182-Cys189. This structural integrity is required for GH-receptor binding and distinguishes HGH 191AA from truncated fragments such as HGH 176-191, which represent only a partial segment of the molecule and exert purely lipolytic effects without IGF-1 stimulation.

Mechanism and Signaling

Binding of HGH 191AA to the membrane-anchored GH receptor drives receptor dimerization. The associated JAK2 kinases undergo trans-phosphorylation and activate downstream STAT5 transcription factors, which translocate to the nucleus and upregulate IGF-1 expression, most prominently in hepatocytes. In parallel, MAPK/ERK and PI3K/AKT cascades are modulated. The resulting rise in circulating IGF-1 represents a central endpoint in many studies of the somatotropic axis. Lipolytic effects in adipocytes arise directly via the GH receptor and are IGF-1 independent.

Research Applications

In preclinical and in-vitro models, HGH 191AA is employed to study protein synthesis, bone and muscle metabolism, fat turnover, and tissue-specific IGF-1 regulation. Unlike fragments, the full 191-AA ligand covers the entire GH axis including anabolic and counter-insulinic effects. Typical experimental endpoints include STAT5 phosphorylation, hepatic IGF-1 mRNA expression, lipolytic rate in adipocyte cultures, and bone-turnover markers in animal models.

Reconstitution and Laboratory Handling

Reconstitution is typically performed with bacteriostatic or sterile water for injection. A 10 IU vial reconstituted with 1 ml yields a concentration of 10 IU/ml, i.e. 1 IU per 0.1 ml. Working dilutions depend on the respective study protocol. Vigorous agitation directly against the vial wall should be avoided to minimize shear stress on the peptide. Early aliquoting after reconstitution is recommended to limit freeze-thaw cycles.

Quality and Documentation

Every batch is tested by HPLC for a minimum purity of 99 percent and verified by mass spectrometry for identity and correct molecular mass. A Certificate of Analysis documents the batch-release results and is available on request. Production follows established GMP-oriented quality standards; batch release is fully traceable. The product is labeled Research Use Only and is not intended for human consumption.

Storage and Stability

The lyophilized peptide is stable for at least 24 months at minus 20 degrees Celsius and should be stored dry, shielded from light and moisture prior to reconstitution. Reconstituted solutions are stable at 2 to 8 degrees Celsius for up to 28 days. For longer storage or repeated experiments, early aliquoting into single-use portions is recommended. The material should equilibrate to room temperature before use.

Compatible Research Peptides

HGH 191AA is frequently studied in parallel with GHRH analogs such as Tesamorelin to distinguish endogenous pulsatile release from exogenous substitution. In regenerative models, BPC-157 and TB-500 are commonly used as separate experimental arms to characterize tissue-specific healing mechanisms independently of IGF-1 signaling. Evaluating individual pathways in isolation offers methodological advantages over single-combination experimental designs.

Safety and Research Use Only

HGH 191AA is intended exclusively for in-vitro experiments and preclinical research. Human or veterinary use outside a documented research context is neither approved nor covered by the product release. Recipients are responsible for compliance with local research regulations, import rules, and internal biosafety policies. The label carries the RUO designation in accordance with international conventions for research materials.