HGH (Somatropin) Research Guide: GH Receptor Mechanism & Technical Data
What Is HGH (Human Growth Hormone)?
Human growth hormone (HGH), known in recombinant form as somatropin, is a 191-amino-acid single-chain polypeptide hormone. Endogenously it is produced by somatotroph cells of the anterior pituitary and is a central regulator of growth, metabolism, and cellular regeneration. In research settings, recombinant HGH is used as a reference hormone in studies of the growth-hormone/IGF-1 axis, protein synthesis, and metabolic signaling.
Mechanism & Research Background
HGH exerts its effects by binding the growth hormone receptor (GHR), a member of the cytokine receptor superfamily. A single HGH molecule bridges two receptor subunits, triggering receptor dimerization and activation of the associated JAK2 kinase. This initiates downstream STAT5 signaling, along with the MAPK and PI3K/AKT pathways. A major consequence of GHR activation is hepatic production of insulin-like growth factor 1 (IGF-1), which mediates many of the anabolic and growth-promoting effects attributed to HGH.
Because of these interconnected pathways, HGH is frequently studied alongside IGF-1 / IGF-1 LR3 and growth-hormone-releasing analogs such as Tesamorelin.
Technical Data
| Compound | Somatropin (recombinant human growth hormone) |
| CAS Number | 12629-01-5 |
| Amino Acids | 191 residues, single chain |
| Molecular Weight | ~22,124 Da (22.1 kDa) |
| Structure | Four-helix bundle with two disulfide bonds |
| Form | Lyophilized powder |
| Target | Growth hormone receptor (GHR) / JAK2-STAT5 |
Handling & Storage
Store lyophilized HGH at −20 °C (or colder for long-term storage), protected from light. As a large, structurally complex protein, HGH is sensitive to heat and mechanical stress. Reconstitute gently with bacteriostatic water directed against the vial wall — avoid vigorous shaking, which can denature the protein — and keep the reconstituted solution refrigerated at 2–8 °C. Avoid freeze-thaw cycling of reconstituted material.
Frequently Asked Questions
How is HGH dosed in units?
Recombinant HGH is often quantified in international units (IU); approximately 3 IU corresponds to roughly 1 mg of somatropin, though exact conversion depends on the preparation.
What is the relationship between HGH and IGF-1?
HGH stimulates the liver to produce IGF-1, which mediates many of its downstream anabolic effects. The two are studied together as the GH/IGF-1 axis.
Why must HGH be handled gently?
It is a large protein whose folded structure can be disrupted by heat, foaming, or vigorous agitation, reducing bioactivity in research assays.
Buy HGH for Research
Zama Biosciences offers HGH (Human Growth Hormone) 24iu for laboratory research. Related growth-axis research compounds include IGF-1 / IGF-1 LR3 and Tesamorelin. Browse the full Peptide Research Library for related mechanism guides.
Research Use Only. All products sold by Zama Biosciences are intended strictly for in-vitro laboratory research and are not for human or veterinary use, consumption, or diagnostic purposes. The information on this page is provided for educational purposes and does not constitute medical advice.