Ipamorelin is a synthetic five-residue growth hormone secretagogue, Aib-His-D-2-Nal-D-Phe-Lys-NH2, that acts on the ghrelin receptor (GHS-R1a). Novo Nordisk described it in 1998.

What makes ipamorelin selective?

In swine it released growth hormone without raising ACTH or cortisol beyond GHRH-like levels, unlike GHRP-6 and GHRP-2, and it did not affect FSH, LH, prolactin or TSH.

What is the ipamorelin half-life?

In healthy men given a 15-minute intravenous infusion, its terminal half-life was 2 hours (Gobburu et al., 1999).

Is ipamorelin a GHRH analogue?

No. It acts on the ghrelin (GHS) receptor. GHRH analogues such as tesamorelin, sermorelin and CJC-1295 act on the GHRH receptor.

Has CJC-1295 with ipamorelin been studied?

Not as that pair. Published work supports GHRH plus GHRP synergy in general, but we found no study of ipamorelin with CJC-1295 specifically.

Does Clean Peptide sell ipamorelin?

Not as a single peptide at the moment. This page is a research summary only.

Ipamorelin Peptide: Structure, GHS-R1a and Research

Ipamorelin is a synthetic five-residue growth hormone secretagogue, Aib-His-D-2-Nal-D-Phe-Lys-NH₂, that acts on the ghrelin receptor (GHS-R1a). Novo Nordisk described it in 1998 as the first selective growth hormone secretagogue, because in animal studies it released growth hormone without the ACTH and cortisol rise seen with older GHRPs. It has been through phase 2 trials but never approved.

Clean Peptide does not stock ipamorelin as a single peptide. This page summarises the compound from published sources only: there is no price, no certificate and no order button.

Notify me if Clean Peptide stocks ipamorelin

Growth-hormone-axis peptides we do stock, each with a per-lot certificate: tesamorelin, CJC-1295 and IGF-1 LR3.

Ipamorelin at a glance

Names	Ipamorelin, NNC 26-0161
Sequence	`Aib-His-D-2-Nal-D-Phe-Lys-NH2`
Residues	5: 2-aminoisobutyric acid (Aib), L-histidine, 3-(2-naphthyl)-D-alanine (D-2-Nal), D-phenylalanine, L-lysinamide
Molecular formula	C₃₈H₄₉N₉O₅
Molecular weight	711.9 g/mol
CAS number	170851-70-4
PubChem CID	9831659
Receptor	Growth hormone secretagogue receptor 1a (GHS-R1a, the ghrelin receptor), UniProt Q92847
Class	Peptidyl GH secretagogue (GHRP class)
Developer	Novo Nordisk, Måløv, Denmark
Regulatory status	Not FDA-approved; listed in FDA’s compounding safety-risk category

Identity: PubChem and the FDA substance registry. It came out of a series of compounds that lack the central Ala-Trp dipeptide of GHRP-1.

How ipamorelin differs from GHRH analogues

Growth hormone release from the pituitary is driven by two separate receptors. Growth hormone-releasing hormone (GHRH) acts on the GHRH receptor; ghrelin, and synthetic secretagogues like ipamorelin, act on the GHS receptor. Tesamorelin, sermorelin and CJC-1295 are GHRH analogues. Ipamorelin belongs to the other pathway, alongside GHRP-2 and GHRP-6. For a side-by-side view, see tesamorelin vs ipamorelin.

Published research on ipamorelin

Discovery and selectivity (1998). In rat pituitary cells, anaesthetised rats and conscious swine, ipamorelin released GH with potency and efficacy similar to GHRP-6. In swine it did not affect FSH, LH, prolactin or TSH and, unlike GHRP-6 and GHRP-2, did not raise ACTH or cortisol beyond GHRH-like levels even far above its GH-releasing dose. Ipamorelin, the first selective growth hormone secretagogue. Raun K, et al. European Journal of Endocrinology, 1998.
Pharmacokinetics in rats (1998). Plasma clearance was five times lower than GHRP-6’s, excretion mainly urinary, and 60–80% was recovered intact; estimated intranasal bioavailability was about 20%. Johansen PB, et al. Xenobiotica, 1998.
Human pharmacokinetics (1999). In healthy men given a 15-minute intravenous infusion, pharmacokinetics were dose-proportional with a terminal half-life of 2 hours, and GH showed a single release episode peaking about 40 minutes after the infusion. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Gobburu JV, et al. Pharmaceutical Research, 1999.
Bone growth in rats (1999). In adult female rats, 15 days of ipamorelin increased tibial growth rate dose-dependently, with no change in total IGF-I or IGF-binding proteins. Johansen PB, et al. Growth Hormone & IGF Research, 1999.
Postoperative ileus model (rats, 2009). As a ghrelin mimetic, ipamorelin shortened time to first bowel movement in a rat model of postoperative ileus. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. Venkova K, et al. Journal of Pharmacology and Experimental Therapeutics, 2009.
Phase 2 in postoperative ileus (2014). In 114 patients after bowel resection (NCT00672074), intravenous ipamorelin was well tolerated but showed no significant difference from placebo on the key efficacy measures. Beck DE, et al. International Journal of Colorectal Disease, 2014.
Review of GH secretagogues (2018). Human data on the class: pulsatile GH release subject to feedback, few long-term controlled studies, and a need for long-term safety data. The Safety and Efficacy of Growth Hormone Secretagogues. Sigalos JT, Pastuszak AW. Sexual Medicine Reviews, 2018.

Ipamorelin with CJC-1295

Ipamorelin is often sold paired with CJC-1295 without DAC (a modified GHRH(1-29)), on the idea that a GHRH analogue and a GHS-receptor agonist act on two different pathways. Published work supports the general GHRH + GHRP synergy, for example GHRH with GHRP-2 in 47 men, but we found no published study of ipamorelin with CJC-1295 specifically. Determinants of GH-releasing hormone and GH-releasing peptide synergy in men. Veldhuis JD, et al. 2009.

Regulatory status

Ipamorelin has never been FDA-approved. FDA’s compounding page lists ipamorelin acetate in category 2 (may present significant safety risks), citing immunogenicity and characterisation concerns and a published report of serious adverse events with intravenous use. FDA compounding safety-risk list.