Somatropin HGH 191-AA Research Kit (with Bacteriostatic Water)

What is Somatropin HGH 191-AA?

Somatropin HGH 191-AA is recombinant human growth hormone (rhGH), a 191-amino-acid single-chain polypeptide produced by recombinant DNA technology with an amino acid sequence identical to the major isoform of native human pituitary growth hormone. It has a molecular weight of approximately 22 kDa and acts through the growth hormone receptor (GHR), a class 1 cytokine receptor.

Somatropin is the peptide studied in licensed medicines within the growth hormone class and has one of the most extensive published clinical and preclinical literatures of any protein. In the laboratory it is used to study GHR signalling, IGF-1 induction, cell proliferation and metabolic regulation, and as a reference standard in immunoassay and bioassay development.

GenoPept supplies somatropin HGH 191-AA in the UK as a research kit: 10 lyophilised vials of somatropin plus a vial of bacteriostatic water, in kit strengths from 60 IU to 360 IU. Each batch is verified by independent HPLC and LC-MS testing and is intended strictly for laboratory research.

Somatropin HGH 191-AA research applications

Growth hormone receptor signalling

Somatropin is used in cell-culture models to study GHR dimerisation, JAK2 activation and STAT5 phosphorylation, the core pathway through which growth hormone regulates gene expression.

IGF-1 induction

Hepatocyte and animal models use somatropin HGH 191-AA to investigate hepatic IGF-1 production, IGF binding proteins and downstream growth signalling.

Metabolic research

Preclinical studies examine somatropin’s effects on lipolysis, glucose handling, protein turnover and body composition in animal models.

Bioassay and immunoassay reference

Because its sequence matches native hGH, somatropin serves as a reference material for GH immunoassays, cell-based bioassays and analytical method development.

Comparative secretagogue studies

Somatropin provides the direct GH comparator against which GHRH analogues and ghrelin receptor agonists such as sermorelin and ipamorelin are benchmarked in research.

Mechanism of action (preclinical)

Somatropin binds the extracellular domain of the growth hormone receptor, inducing receptor dimerisation and activation of the associated tyrosine kinase JAK2. JAK2 phosphorylates STAT5 and other signalling proteins, which move to the nucleus and regulate transcription of IGF-1 and a wide range of growth and metabolic genes.

Downstream effects in preclinical models include hepatic IGF-1 release, lipolysis in adipose tissue, amino acid uptake in muscle and altered glucose metabolism. Unlike secretagogues, somatropin acts directly at the tissue receptor and bypasses the pituitary, which is why it is used as the reference agonist in GH axis research.

Somatropin HGH 191-AA product specifications

Available sizes

• 60 IU Kit (10×6iu)
• 100 IU Kit (10×10iu)
• 120 IU Kit (10×12iu)
• 150 IU Kit (10×15iu)
• 240 IU Kit (10×24iu)
• 360 IU Kit (10×36iu)

Each kit already contains 10 vials, and laboratories running larger programmes can request multi-kit wholesale pricing through the bulk and wholesale page. Orders over £200 ship free by tracked Royal Mail Special Delivery within the UK.

Reconstitution, handling and storage (laboratory)

Each somatropin research kit contains 10 lyophilised vials of somatropin plus a vial of bacteriostatic water for reconstitution. Store the unopened lyophilised vials at -20 °C for long-term stability, or at 2-8 °C for short periods, protected from light. Allow a vial to reach room temperature before opening to prevent condensation on the powder.

Somatropin is a 22 kDa protein and is more shear-sensitive than small peptides. Add the supplied bacteriostatic water slowly down the inside wall of the vial and swirl gently until the powder dissolves; never shake, as agitation can cause aggregation and reduce measured activity and purity.

After reconstitution, keep the solution at 2-8 °C and use it within the period stated in your laboratory protocol. Further guidance is available in our articles on how to reconstitute research peptides and how to store research peptides, and additional bacteriostatic water is available separately.

Quality assurance and Certificate of Analysis

Every batch of Somatropin HGH 191-AA sold by GenoPept is tested by an independent ISO/IEC 17025 laboratory (Puralytix). HPLC confirms purity of 99% or higher and LC-MS confirms molecular identity, so the compound in the vial matches the label.

Each product page carries a “View Certificate of Analysis” button, and the complete library is published at genopept.co.uk/coa-certificates. Vials are batch-identified with lot number and expiry date, and our guide to what a Certificate of Analysis shows explains how to read the report.

Related research compounds

• IGF-1 LR3: the downstream growth factor for studying the GH/IGF-1 axis end to end.
• Sermorelin (GRF 1-29): a GHRH analogue for studying pituitary GH release rather than direct receptor activation.
• CJC-1295 + Ipamorelin Blend: a two-pathway secretagogue combination benchmarked against exogenous GH in models.
• HGH Fragment 176-191: the C-terminal fragment of growth hormone studied in lipid metabolism research.

Somatropin HGH 191-AA frequently asked questions

What is somatropin HGH 191-AA used for in research?

Somatropin HGH 191-AA is used in laboratory research as the reference agonist for the growth hormone receptor. Applications include cell-culture studies of GHR, JAK2 and STAT5 signalling, hepatocyte and animal models of IGF-1 induction, metabolic research on lipolysis and glucose handling, and use as a reference material in immunoassays and bioassays. Supplied strictly for in-vitro research.

How is the somatropin research kit supplied and what purity does it have?

Each GenoPept kit contains 10 sealed, sterile glass vials of lyophilised somatropin plus a vial of bacteriostatic water. Kits are available in 60, 100, 120, 150, 240 and 360 IU strengths, with the IU per vial equal to the kit total divided by 10. Every batch is tested by an independent ISO/IEC 17025 laboratory with HPLC and LC-MS, and the COA is on the product page.

How should somatropin be stored?

Store unopened lyophilised somatropin vials at -20 °C for long-term stability, or at 2-8 °C for short periods, protected from light. After reconstitution with the supplied bacteriostatic water, keep the solution refrigerated at 2-8 °C and use it within the period stated in your laboratory protocol. Because somatropin is a protein, avoid shaking and repeated freeze-thaw cycles.

Is somatropin HGH for human use?

No. Somatropin HGH 191-AA research kits from GenoPept are supplied for in-vitro laboratory research only. They are not medicines, are not for human or veterinary use, and are not for diagnostic or therapeutic purposes. GenoPept provides no dosing or administration information, and purchasers must confirm they are buying for legitimate research use in the UK.

What does 191-AA mean and how does somatropin differ from secretagogues?

191-AA indicates that the protein contains all 191 amino acids of native human growth hormone, distinguishing it from 192-amino-acid variants with an extra N-terminal methionine. Somatropin acts directly at the growth hormone receptor in tissues, whereas secretagogues such as sermorelin, CJC-1295 and ipamorelin act on the pituitary to release endogenous GH. Researchers use somatropin when direct receptor activation is required.

Research use only. This product is supplied for in-vitro laboratory research only. It is not for human or veterinary use, not a medicine, and not for diagnostic or therapeutic use. See our research use only policy and UK legal guide.