What is Ipamorelin?
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) first described in the late 1990s and characterized in the literature as a growth hormone secretagogue (GHS). It belongs to a class of compounds derived structurally from the growth hormone-releasing peptide (GHRP) family, but it was identified within a series of analogues lacking the central Ala-Trp dipeptide of GHRP-1.
In the foundational characterization by Raun and colleagues, Ipamorelin was reported as the first GHRP-receptor agonist with a selectivity for growth hormone release described as similar to that of growth hormone-releasing hormone (GHRH). It is studied strictly as a research chemical, and VANTA supplies it for in-vitro and laboratory research applications only, not for human or veterinary use.
Studied mechanisms
In the published literature, Ipamorelin is described as an agonist of the growth hormone secretagogue receptor (GHS-R1a), the G-protein-coupled receptor that also recognizes the endogenous ligand ghrelin. Pharmacological profiling using GHRP and GHRH antagonists indicated, in preclinical systems, that Ipamorelin acts via a GHRP-like receptor pathway rather than the GHRH receptor.
A recurring theme in the literature is selectivity. In rodent and in-vitro models, researchers reported that Ipamorelin released growth hormone from primary pituitary cells with potency comparable to GHRP-6, while investigators observed no significant change in ACTH or cortisol relative to GHRH stimulation, even at doses far above the ED50 for growth hormone release. These observations are mechanistic findings within research models and are not statements about human physiology.
Research models and findings (hedged)
Ipamorelin has been examined across several preclinical contexts. The original work by Raun et al. characterized growth hormone release in rat pituitary cells and in vivo in rodents and swine. Chronic-dosing work in young female rats examined somatotroph responses in vitro following repeated administration.
Gastrointestinal models have also been reported: in a rodent model of postoperative ileus, investigators examined whether Ipamorelin, as a ghrelin-receptor agonist, was associated with changes in colonic transit and fecal output. Separate studies have explored Ipamorelin in models of glucocorticoid-associated bone changes and have investigated mechanisms of insulin release from rat pancreatic tissue. These are descriptions of what researchers measured in animal and tissue models; none should be read as indicating any outcome in humans or as guidance toward use.
Why selectivity is a recurring research theme
Much of the academic interest summarized above centers on the reported selectivity profile of Ipamorelin within experimental systems. In the preclinical literature, none of the growth hormone secretagogues tested significantly altered FSH, LH, prolactin, or TSH levels, and Ipamorelin in particular was distinguished from GHRP-6 and GHRP-2 by the absence of a significant ACTH or cortisol response in the models studied.
For researchers, this makes Ipamorelin a commonly referenced tool compound when designing experiments that aim to probe GHS-R signaling with a comparatively narrow reported endocrine footprint in animal and cell-based models. As always, these are literature-derived observations to inform experimental design, not assertions of effect outside the cited research settings.
How VANTA verifies it
Every Ipamorelin lot VANTA supplies is screened for identity and purity before release. Mass-spectrometry (MS) is used to confirm molecular identity against the expected pentapeptide mass, and reversed-phase high-performance liquid chromatography (HPLC) is used to quantify chromatographic purity.
Each batch ships with a per-batch Certificate of Analysis (COA) documenting the HPLC purity figure and the MS identity confirmation for that specific lot, so researchers can match the material in hand to its analytical record. This documentation supports reproducibility and traceability in the lab. VANTA provides Ipamorelin as a reference-grade research compound for laboratory use only; it is not a drug, supplement, or article intended for human or animal consumption.
References
- 1.Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998 (foundational mechanism + selectivity characterization).
- 2.Venkova K, et al. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. J Pharmacol Exp Ther. 2009.
- 3.Andersen NB, et al. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats. Growth Horm IGF Res. 2001.
- 4.Adeghate E, Ponery AS. Mechanism of ipamorelin-evoked insulin release from the pancreas of normal and diabetic rats. Neuro Endocrinol Lett. 2004.
- 5.Jiménez-Reina L, et al. Influence of chronic treatment with the growth hormone secretagogue Ipamorelin in young female rats: somatotroph response in vitro. Histol Histopathol. 2002.