What is the GH/IGF-1 axis?
The GH/IGF-1 axis is the coupled endocrine signalling architecture spanning pituitary growth hormone release through hepatic insulin-like growth factor 1 synthesis to peripheral-tissue anabolic effects. The central pharmacological axis for the GHRH-analogue and GH-secretagogue compound class.
What the research literature says
The GH/IGF-1 axis links three principal endocrine layers. (1) Pituitary somatotroph cells synthesise and release growth hormone in pulsatile fashion under regulation by hypothalamic GHRH (stimulatory) and somatostatin (inhibitory) inputs. (2) Circulating GH engages the GH receptor on hepatocytes (and on peripheral tissues directly), driving hepatic IGF-1 synthesis. (3) Circulating IGF-1 (bound to IGFBP-3) reaches peripheral tissues and engages the IGF-1 receptor — a receptor tyrosine kinase structurally related to the insulin receptor — driving anabolic, mitogenic, and growth-promoting effects.
The axis is the central pharmacological framework for the GHRH-analogue compound class (CJC-1295, tesamorelin) which acts at the pituitary GHRH receptor at the upstream end of the axis, and for the GH secretagogue compound class (ipamorelin) which acts at the parallel ghrelin receptor on the same somatotroph cells. Both classes drive GH release and downstream IGF-1 elevation as the canonical pharmacological readout. The Teichman CJC-1295 clinical-pharmacology work documented the axis activation (PMID 16352683); the Sackmann-Sala serum-protein-profile work characterised the integrated downstream consequences (PMID 19386527).
The Sattler GH-aging-research review consolidates the axis biology in the aging-male context (PMID 24054930). The Chang BPC-157 tendon-fibroblast work documented growth-hormone-receptor up-regulation as the mechanism for the compound’s tendon-research findings (PMID 21030672) — a parallel framework for engaging the axis at the receptor level rather than at the pituitary-release level.
Why this matters in research context
The GH/IGF-1 axis matters in peptide-research contexts as the framework that ties together the GHRH-analogue class, the GH-secretagogue class, and BPC-157’s tendon-research mechanism. Researchers studying any of these compounds should anchor protocol design to the integrated axis biology — circulating IGF-1 is the canonical downstream biomarker because it integrates the pulsatile GH-release signal into a more measurable time-averaged readout.
Related compounds
- CJC-1295 No DAC 10mg — GHRH-receptor agonist
- Ipamorelin 10mg — GH secretagogue
- Tesamorelin 10mg — GHRH-receptor agonist
Related research questions
References
- Chang CH et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol 2011;110(3):774-780. [PMID 21030672]
- Teichman SL et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab 2006;91(3):799-805. [PMID 16352683]
- Sackmann-Sala L et al. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth Horm IGF Res 2009;19(6):471-477. [PMID 19386527]
- Sattler FR. Growth hormone in the aging male. Best Pract Res Clin Endocrinol Metab 2013;27(4):541-555. [PMID 24054930]
Research-questions pages describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. Every compound in the Ronin catalog is sold strictly for laboratory and research use only.