Research At a Glance
- Research Category
- Growth Hormone Axis Research
- Peptide Length
- 5 amino acids (pentapeptide)
- Purity
- ≥ 99% (HPLC)
- Published Studies
- ~50 indexed
- Storage
- Lyophilized: 2–8 °C, protected from light. Reconstituted: 2–8 °C, use within 30 days.
Published-study figures are approximate PubMed result counts and indicate the volume of available literature only. Purity reflects third-party analytical testing on the corresponding lot; see the Quality Assurance Center for lot-matched certificates.
Overview
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that functions as a selective agonist of the growth hormone secretagogue receptor (GHS-R1a), the same receptor activated by endogenous ghrelin. It was identified within a chemistry program screening compounds derived from growth hormone-releasing peptide (GHRP)-1, and is distinguished from earlier-generation GHRPs (such as GHRP-6 and GHRP-2) by its receptor selectivity: published research reports that ipamorelin stimulates GH release without meaningfully elevating cortisol, prolactin, or ACTH, even at doses substantially higher than its GH-releasing effective dose.
Citation
Raun K., et al., European Journal of Endocrinology, 1998
History
Ipamorelin was first described in 1998 by Kirsten Raun and colleagues at Novo Nordisk, who identified it within a series of compounds lacking the central Ala-Trp dipeptide of GHRP-1. In vitro, it released GH from primary rat pituitary cells with potency comparable to earlier GHRPs, but in vivo studies in swine notably found no significant elevation of ACTH or cortisol — a selectivity result that distinguished it from GHRP-6 and GHRP-2, both of which increased those hormones in the same experimental system. Subsequent research extended into rat models examining longitudinal bone growth and bone histomorphometry.
Citation
Raun K., et al., European Journal of Endocrinology, 1998
Structure
| CAS # | 170851-70-4 |
|---|---|
| Molecular Formula | C38H49N9O5 |
| Molecular Weight | 711.85 g/mol |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 |
Research Findings
Ipamorelin has been studied in pituitary cell culture and animal models for GH-axis selectivity and downstream growth effects.
Key Areas of Research
- Endocrine: GHS-R1a-selective GH release via Gq/11-mediated phospholipase C activation and calcium signaling
- Selectivity: Minimal cortisol, prolactin, and ACTH elevation compared to earlier GHRPs, even at high multiples of effective dose
- Musculoskeletal: Longitudinal bone growth and cortical bone histomorphometry changes in rat models
- Gastrointestinal: Research into gastric motility effects, distinguishing it from ghrelin’s broader appetite-stimulating activity
Summary
Together, these findings position ipamorelin as the reference compound for receptor-selective GH secretagogue research, valued specifically because its GHS-R1a activation appears decoupled from the broader hypothalamic-pituitary-adrenal axis activation seen with earlier GHRPs. Human clinical data remain limited to a small number of pharmacokinetic/pharmacodynamic studies and a discontinued Phase II trial, with most published evidence derived from rodent and porcine models.
Citation
Raun K., et al., European Journal of Endocrinology, 1998
References
- Raun K., Hansen B.S., Johansen N.L., Thøgersen H., Madsen K., Ankersen M., Andersen P.H. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology.
- Johansen P.B., et al. (1999). Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Hormone & IGF Research.
- Beck Jensen J.E., et al. (2001). Ipamorelin-related changes in cortical bone histomorphometry. Bone.
Source
Literature available via PubMed — ipamorelin research .
Certificate of Analysis
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