Ipamorelin is a synthetic pentapeptide originally described as a selective growth-hormone secretagogue that interacts with the ghrelin / GHS-R receptor.

What receptor does Ipamorelin interact with?

The published literature describes Ipamorelin as an agonist at the ghrelin / growth-hormone secretagogue receptor (GHS-R).

Is Ipamorelin a ghrelin receptor agonist?

Yes, the published characterisation identifies Ipamorelin as a GHS-R (ghrelin receptor) agonist in the tested in-vitro and preclinical contexts.

Is Ipamorelin the same as CJC-1295?

No. Ipamorelin is a pentapeptide that interacts with the ghrelin receptor. CJC-1295 (with DAC) and the peptide labelled 'CJC-1295 No DAC' are GHRH-related analogues with different structures, mechanisms and half-lives. They are frequently discussed together but are chemically and pharmacologically distinct.

Is Ipamorelin contained in HULK?

Yes. HULK is a two-component PepDirect research blend containing Ipamorelin and CJC-1295 without DAC.

Is PepDirect Ipamorelin intended for human use?

No. PepDirect supplies Ipamorelin strictly as a laboratory research material. It is not marketed as a medicine, food supplement or product for human or veterinary use.

↳ Research overview

What Is Ipamorelin?

Ipamorelin is a synthetic pentapeptide investigated for activity at the ghrelin / growth-hormone secretagogue receptor (GHS-R). It is a selective research compound with a defined published mechanistic profile.

This guide covers Ipamorelin's chemical identity, its receptor pharmacology, its relationship to CJC-1295 in research literature and its role as a component of PepDirect's HULK blend.

For laboratory research context only. PepDirect supplies Ipamorelin as a research material, not for human or veterinary use.

§ Identity

What is Ipamorelin?

Ipamorelin is a synthetic pentapeptide originally described by Novo Nordisk researchers (Raun et al., 1998) as the first highly selective growth-hormone secretagogue. It was designed to interact with the ghrelin receptor (GHS-R) with reported selectivity relative to other endocrine axes at the concentrations tested in the original characterisation.

Compound name: Ipamorelin
CAS number: 170851-70-4
Molecular formula: C38H49N9O5
Molecular weight: ~711.85 g/mol
PubChem CID: 9831659
Length: 5 amino acids (pentapeptide)

Lot-specific identity and purity for a supplied batch should always be verified against the printed lot number and its corresponding Certificate of Analysis.

§ Receptor

Which receptor does Ipamorelin interact with?

Ipamorelin is described in the published literature as a ghrelin-receptor / growth-hormone secretagogue receptor (GHS-R) agonist. GHS-R is the endogenous receptor for ghrelin and is involved in the growth-hormone secretagogue pathway.

Receptor-level activity does not, in itself, establish downstream outcomes in humans or animals. Interpreting Ipamorelin research means distinguishing (1) in-vitro receptor pharmacology, (2) preclinical endocrine responses in animal models, and (3) any published human research, which is comparatively limited and should not be extrapolated from preclinical findings.

§ Research themes

Ipamorelin research context

Ghrelin-receptor / GHS-R signalling, in-vitro receptor pharmacology.
Growth-hormone secretagogue pathway research, endocrine models.
Comparative receptor-selectivity studies vs earlier secretagogues (e.g. GHRP-6, hexarelin).
Endocrine signalling and neuroendocrine research models (largely preclinical).

The research themes above describe areas of published investigation. They are not statements of demonstrated benefits for body composition, muscle growth, recovery or any human clinical outcome.

§ vs CJC-1295

Ipamorelin and CJC-1295

Ipamorelin and CJC-1295 are frequently discussed together in growth-hormone-secretagogue research because they interact with different, complementary points in the same broad endocrine pathway: Ipamorelin acts at the ghrelin receptor, while CJC-1295 is a GHRH-related analogue.

Chemically and pharmacologically they are distinct compounds. Ipamorelin is a synthetic pentapeptide; CJC-1295 with DAC and the peptide commonly labelled 'CJC-1295 No DAC' (Modified GRF 1-29) are different peptides with different mechanisms and half-lives, see the CJC-1295 DAC vs No DAC guide for the structural comparison.

§ In blends

Ipamorelin in the HULK blend

Ipamorelin is one of two components in PepDirect's HULK research blend, alongside CJC-1295 (without DAC / Modified GRF 1-29). The two components are supplied together as a defined multi-component preparation.

Published research involving Ipamorelin alone does not automatically establish equivalent findings for the combined HULK blend. Blend-level conclusions require research on the specific combined preparation.

§ Research product

View the Ipamorelin research product

Ipamorelin is supplied by PepDirect as a lyophilised research material with lot-specific documentation.

View Ipamorelin Research Peptide →

§ References

Selected research references

Ipamorelin · PubChem CID 9831659PubChem (NCBI)
Ipamorelin, the first selective growth hormone secretagogue (Raun et al., 1998)PubMed · Eur J Endocrinol
Growth-hormone secretagogue receptor (GHSR) pharmacology reviewPubMed · Kojima & Kangawa
Ghrelin, GHS-R and the growth-hormone secretagogue system, reviewPubMed · Howard et al.

§ FAQ

Frequently asked questions

What is Ipamorelin?: Ipamorelin is a synthetic pentapeptide originally described as a selective growth-hormone secretagogue that interacts with the ghrelin / GHS-R receptor.
What receptor does Ipamorelin interact with?: The published literature describes Ipamorelin as an agonist at the ghrelin / growth-hormone secretagogue receptor (GHS-R).
Is Ipamorelin a ghrelin receptor agonist?: Yes, the published characterisation identifies Ipamorelin as a GHS-R (ghrelin receptor) agonist in the tested in-vitro and preclinical contexts.
Is Ipamorelin the same as CJC-1295?: No. Ipamorelin is a pentapeptide that interacts with the ghrelin receptor. CJC-1295 (with DAC) and the peptide labelled 'CJC-1295 No DAC' are GHRH-related analogues with different structures, mechanisms and half-lives. They are frequently discussed together but are chemically and pharmacologically distinct.
Is Ipamorelin contained in HULK?: Yes. HULK is a two-component PepDirect research blend containing Ipamorelin and CJC-1295 without DAC.
Is PepDirect Ipamorelin intended for human use?: No. PepDirect supplies Ipamorelin strictly as a laboratory research material. It is not marketed as a medicine, food supplement or product for human or veterinary use.

§ Related