Ipamorelin (Selective GH Secretagogue)

Ipamorelin is a synthetic pentapeptide and one of the most selective growth hormone secretagogues described in the research literature. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, it carries CAS number 170851-70-4, and its molecular formula is C38H49N9O5 with a molecular weight of 711.9 g/mol. It was introduced in 1998 by a group at Novo Nordisk as the first selective secretagogue of its kind.

The word selective is the central idea. In the original research, ipamorelin prompted growth hormone release in models without the rise in cortisol and prolactin seen with some earlier secretagogues. That selectivity is why it remains a reference compound in growth-hormone research. It is supplied as a lyophilized powder for laboratory reconstitution.

Ipamorelin was first characterized by Raun and colleagues in a 1998 paper in the European Journal of Endocrinology describing it as the first selective growth hormone secretagogue (PubMed 9849822). The study laid out its potency and, importantly, its clean selectivity profile relative to other secretagogues of the era.

Later research placed ipamorelin in specific physiological models. A 2001 study by Andersen and colleagues in Growth Hormone and IGF Research examined it in a glucocorticoid-induced bone model (PubMed 11735244), and a 2002 paper by Jimenez-Reina and colleagues in Histology and Histopathology looked at chronic treatment effects on pituitary cells (PubMed 12168778). A 2024 study in Physiology and Behavior examined ghrelin-receptor agonists including ipamorelin in other model systems (PubMed 39043357).

The literature is largely preclinical, with the 1998 characterization remaining the anchor reference.

Ipamorelin acts as an agonist at the growth hormone secretagogue receptor (GHS-R1a), the same receptor targeted by the hormone ghrelin. Activating this receptor on the pituitary is studied for its ability to trigger pulses of growth hormone release. Unlike GHRH analogs such as CJC-1295, which work through the GHRH receptor, ipamorelin works through the ghrelin pathway.

Its defining feature in research is selectivity. The original work reported that it released growth hormone with little effect on cortisol, prolactin, or other pituitary hormones, distinguishing it from secretagogues like GHRP-6. This is the basis for studying it together with a GHRH analog, since the two receptors can be examined for additive effects.

Most ipamorelin findings come from animal and cell models, and dosing and delivery vary by study. For current findings, search PubMed directly.

Lyophilized ipamorelin is stored at -20°C for long-term holding, shielded from light, and repeated freeze-thaw cycles are avoided. Stability for a given lot is documented on its Certificate of Analysis. Refrigeration at 2°C to 8°C suits shorter windows, with the vial protected from light and moisture.

Freeze-thaw cycling is avoided. The lot-specific Certificate of Analysis is the authoritative reference for a given batch.

Reconstitution means returning a lyophilized compound to solution. This page gives no preparation procedure: solvent, concentration and handling steps belong to the methodology of the study being reproduced, not to a compound reference. ipamorelin is handled as aqueous-soluble material.

Lyophilized material is hygroscopic, so a sealed container is allowed to reach ambient temperature before it is opened. Solubility and water-content figures for a given lot appear on its Certificate of Analysis.

Identity and purity of research-grade ipamorelin are established analytically, by HPLC with mass spectrometric confirmation of the expected mass. Verified purity is documented per lot on the Certificate of Analysis. Net peptide content is a useful figure to check, since it reflects how much actual peptide is present beyond counterions and moisture.

On a Certificate of Analysis, confirm HPLC purity, the mass-spec identity, and net peptide content. peptides.com publishes lot-specific lab reports so buyers can verify the material before purchase.

Ipamorelin is most often cross-referenced with other growth-hormone-axis research peptides:

• CJC-1295.
  A GHRH analog frequently paired with ipamorelin in research. 
• Sermorelin.
  A GRF(1-29) analog studied in the growth-hormone axis (entry forthcoming).
• Hexarelin.
  A growth-hormone-releasing peptide in the same secretagogue family (entry forthcoming).
• Tesamorelin.
  A stabilized GHRH analog studied in metabolic models (entry forthcoming).

Raun K, Hansen BS, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology.
PubMed 9849822

Andersen NB, Malmlof K, et al. (2001). The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation. Growth Hormone and IGF Research.
PubMed 11735244

Jimenez-Reina L, Canete R, et al. (2002). Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats. Histology and Histopathology.
PubMed 12168778

Lu Z, Ngan MP, et al. (2024). The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced emesis. Physiology and Behavior.
PubMed 39043357

peptides.com carries ipamorelin in research-grade lyophilized vials and in combination formats with CJC-1295 and tesamorelin. Each ships with a batch-specific Certificate of Analysis.

• Browse all ipamorelin research products
• Real Peptides Ipamorelin (10mg vial)
• Catalyst Compounds Ipamorelin (5mg to 10mg vial)
• CJC-1295 (No DAC) + Ipamorelin combination
• Collections: Research Vials. Documentation: COA and Lab Testing.

These products are sold for Research Use Only and are not intended for human consumption.