HGH (Somatropin)
HGH (Somatropin) recombinant 191-amino-acid human growth hormone. Lyophilized powder, ≥99% purity by HPLC. For research use only.
About HGH (Somatropin)
What is HGH (Somatropin)?
HGH – human growth hormone, also known by its generic name somatropin – is a protein hormone naturally produced by the somatotroph cells of the anterior pituitary. The HGH offered by Virexa Labs is a recombinant form: a 191-amino-acid protein with a molecular weight of approximately 22 kDa, matching the sequence of the main circulating form of pituitary GH.
Unlike the other compounds in this category, HGH is not a secretagogue that stimulates GH release – it is the hormone itself. That makes it the reference compound in studies of the GH receptor and its downstream signalling. It is supplied for in-vitro laboratory research only and is not intended for human or veterinary use.
Structure and mechanism
Somatropin is a single-chain protein that folds into a four-helix bundle stabilised by two disulfide bridges. This three-dimensional structure is essential for receptor binding, which is why the protein is much more sensitive to handling than small peptides.
HGH binds to the growth hormone receptor (GHR), a cytokine-type receptor. One HGH molecule engages two receptor units, and this dimerisation activates the JAK2–STAT5 signalling pathway – the route most commonly studied in relation to IGF-1 expression in liver-cell models.
Research areas
Recombinant somatropin is used in laboratory studies of:
- GH receptor binding and receptor dimerisation
- JAK2–STAT5 signalling and IGF-1 gene expression in cell models
- protein synthesis and cell proliferation in in-vitro systems
- comparisons between direct GH exposure and GH secretagogues such as GHRH analogues and ghrelin receptor agonists
Handling, reconstitution and storage
Because HGH is a large, folded protein, gentle handling is especially important. Reconstitute with bacteriostatic water, letting it run slowly down the inside wall of the vial, then swirl or roll the vial gently until the powder has dissolved. Never shake: mechanical stress can denature the protein and cause aggregation.
Store lyophilised HGH at −20 °C, dry and protected from light (2–8 °C short term). Once reconstituted, keep it at 2–8 °C, use within about 4 weeks and avoid freeze–thaw cycles. Each batch is checked by HPLC (≥99% purity) and mass spectrometry, with the COA available on this page. To buy HGH for research, order directly here.
Frequently asked questions
What is HGH (Somatropin)?
HGH, or somatropin, is recombinant human growth hormone: a 191-amino-acid protein of about 22 kDa. It is used as a research compound in studies of the GH receptor and its signalling.
What is the difference between HGH and peptides such as Ipamorelin or CJC-1295?
HGH is the growth hormone itself and acts directly on the GH receptor. Ipamorelin and CJC-1295 are secretagogues: they are studied for their ability to stimulate GH release from pituitary cells via the ghrelin receptor and the GHRH receptor respectively.
How do I store HGH?
Lyophilised: at −20 °C, dry and dark (2–8 °C short term). Reconstituted: at 2–8 °C, use within about 4 weeks and avoid freeze–thaw cycles.
What do I reconstitute HGH with?
Bacteriostatic water is usually used. Add it slowly along the vial wall and swirl gently – never shake, because the protein structure is sensitive to mechanical stress.
Is HGH suitable for human use?
No. This HGH is intended exclusively for in-vitro laboratory research and is not for human or veterinary use.