Sermorelin, Ipamorelin & CJC-1295: Growth Hormone Secretagogues in Research
For laboratory and research use only. This article summarises published scientific research on growth hormone secretagogue peptides. Neurovia peptides are not intended for human consumption. See our disclaimer.
Sermorelin, Ipamorelin & CJC-1295: Growth Hormone Secretagogues in Research
Sermorelin, Ipamorelin, and CJC-1295 belong to a class of research peptides studied in the context of the growth hormone (GH) axis — specifically as growth hormone secretagogues (GHS): compounds that stimulate the release of growth hormone from the pituitary gland in preclinical models.
This article provides an evidence-based overview of each peptide, their molecular profiles, the published research landscape, and how they compare in research contexts.
What Are Growth Hormone Secretagogues?
Growth hormone secretagogues are compounds studied for their ability to stimulate the pituitary gland to release endogenous growth hormone, rather than supplying exogenous GH directly.
Two receptor systems are relevant to this class:
GHRH receptors (Growth Hormone Releasing Hormone receptors) — activated by GHRH-analogue peptides such as Sermorelin, CJC-1295, and Tesamorelin. These act on the pituitary via the GHRH pathway.
Ghrelin/GHS receptors (GHSR-1a) — activated by ghrelin-mimetic peptides such as Ipamorelin and GHRP-2. These represent a distinct receptor pathway that also stimulates GH release.
In preclinical research, compounds acting on these two pathways are often studied in combination, as they activate complementary mechanisms and have been shown to produce additive effects on GH secretion in animal models.
What Is Sermorelin?
Sermorelin (GHRH 1-29) is a synthetic analogue of the first 29 amino acids of endogenous Growth Hormone Releasing Hormone (GHRH). Endogenous GHRH is a 44-amino acid hypothalamic peptide; sermorelin represents the biologically active N-terminal fragment.
Molecular profile:
- Length: 29 amino acids
- Molecular weight: ~3357 Da
- Mechanism: GHRH receptor agonist
- CAS Number: 86168-78-7
Sermorelin was approved by the FDA as a pharmaceutical (Geref) for use in growth hormone deficiency diagnosis and treatment in children — making it one of the few peptides in this research category with historical clinical data. It was withdrawn from the market in 2008 for commercial reasons, not safety concerns.
Sermorelin Research
Published research on sermorelin covers GHRH receptor binding kinetics, pituitary GH secretion in animal models, and pharmacokinetic studies. As a truncated GHRH analogue, sermorelin research has investigated the minimum active sequence required for GHRH receptor activation.
Key distinguishing feature in research: sermorelin has a relatively short half-life in solution — estimated at approximately 10–20 minutes in vivo in published animal pharmacokinetic studies — due to rapid enzymatic degradation by dipeptidyl peptidase IV (DPP-IV).
What Is CJC-1295?
CJC-1295 is a synthetic GHRH analogue engineered to extend the half-life of sermorelin. Two versions are studied in research:
CJC-1295 with DAC (Drug Affinity Complex) — incorporates a lysine-maleimide linker that covalently binds to albumin in the bloodstream, dramatically extending half-life to approximately 6–8 days in animal models. Also known as DAC:GRF.
CJC-1295 without DAC (Mod GRF 1-29) — the modified 29-amino acid sequence without the albumin-binding component, with a half-life similar to or slightly longer than sermorelin. This is what most research suppliers offer as “CJC-1295 No DAC.”
CJC-1295 Research
Published research has examined CJC-1295’s extended pharmacokinetic profile compared to sermorelin, with studies demonstrating sustained GH and IGF-1 elevation in animal models over longer periods than unmodified GHRH analogues.
The CJC-1295 with DAC research literature includes work published in journals including Journal of Clinical Endocrinology & Metabolism, establishing the pharmacokinetic extension achieved through albumin binding.
What Is Ipamorelin?
Ipamorelin is a synthetic pentapeptide (5 amino acids) and selective growth hormone secretagogue receptor (GHSR) agonist. Unlike earlier GHRP compounds (GHRP-2, GHRP-6), ipamorelin was developed specifically for selectivity — designed to stimulate GH release with minimal effect on other pituitary hormones such as cortisol and prolactin in preclinical studies.
Molecular profile:
- Length: 5 amino acids (Aib-His-D-2-Nal-D-Phe-Lys-NH2)
- Molecular weight: ~711 Da
- Mechanism: GHSR-1a agonist
- CAS Number: 170851-70-4
Ipamorelin Research
Ipamorelin was originally developed and researched by Novo Nordisk in the 1990s. Published research includes the original characterisation study by Bowers et al. and subsequent work establishing ipamorelin’s selectivity profile compared to other GHRP compounds.
Published studies have examined ipamorelin’s GH secretory profile in rat models, its selectivity for GHSR-1a over other receptor subtypes, and its studied effects on bone density and body composition in animal models.
The selectivity of ipamorelin — specifically its studied lack of significant cortisol and prolactin elevation compared to GHRP-2 and GHRP-6 — is a key focus of the published comparative research.
CJC-1295 / Ipamorelin in Combination Research
The combination of a GHRH-analogue (CJC-1295 or sermorelin) with a GHSR agonist (ipamorelin) has been studied in preclinical research as a dual-pathway approach to stimulating GH secretion.
Published research has demonstrated synergistic or additive effects on GH release when GHRH-pathway and ghrelin-pathway compounds are combined in animal models, which has made this combination one of the most referenced in preclinical GH axis research.
Neurovia supplies this combination in both the CJC-1295 / Ipamorelin 10/10mg and 5/5mg vial formats, as well as the Tesamorelin / CJC-1295 No DAC / Ipamorelin triple blend.
What Is Tesamorelin?
Tesamorelin is a GHRH analogue with an added trans-3-hexenoic acid group that stabilises the peptide against DPP-IV degradation. It has received FDA approval as a pharmaceutical (Egrifta) for a specific HIV-related lipodystrophy indication — the only GHRH analogue currently with active FDA-approved status.
In research contexts, tesamorelin is studied as a longer-acting GHRH analogue, with published pharmacokinetic data demonstrating extended activity compared to sermorelin.
Comparing the GH Secretagogue Peptides
| Peptide | Type | Receptor | Half-life | Research origin |
|---|---|---|---|---|
| Sermorelin | GHRH analogue (1-29) | GHRH-R | ~10–20 min | Endogenous GHRH fragment |
| CJC-1295 No DAC | Modified GHRH analogue | GHRH-R | ~30 min | Engineered sermorelin |
| CJC-1295 with DAC | Albumin-binding GHRH | GHRH-R | ~6–8 days | Engineered for extended t½ |
| Ipamorelin | Synthetic pentapeptide | GHSR-1a | ~2 hours | Novo Nordisk development |
| Tesamorelin | Stabilised GHRH analogue | GHRH-R | ~30 min | FDA-approved analogue |
Further reading: peer-reviewed research on Sermorelin (PubMed).
Frequently Asked Questions
What is sermorelin research peptide?
Sermorelin (GHRH 1-29) is a synthetic analogue of the first 29 amino acids of growth hormone releasing hormone. It is studied as a GHRH receptor agonist in preclinical research on the growth hormone axis.
What is ipamorelin research peptide?
Ipamorelin is a synthetic 5-amino acid growth hormone secretagogue receptor (GHSR-1a) agonist. It is studied for its selective stimulation of GH secretion in animal models, with published research noting minimal effect on cortisol and prolactin compared to earlier GHRP compounds.
What is CJC-1295 peptide?
CJC-1295 is a modified GHRH analogue engineered to extend the half-life of sermorelin. It is available as CJC-1295 No DAC (Mod GRF 1-29) and CJC-1295 with DAC — the latter using an albumin-binding complex to achieve a half-life of approximately 6–8 days in animal models.
What is the difference between sermorelin and ipamorelin?
Sermorelin is a GHRH receptor agonist — it acts on the GHRH pathway to stimulate GH release. Ipamorelin is a GHSR agonist — it acts on the ghrelin receptor pathway. They represent two distinct mechanisms for stimulating pituitary GH secretion, and are often studied in combination in preclinical research for their complementary effects.
What is CJC-1295 No DAC?
CJC-1295 No DAC (also called Mod GRF 1-29) is the modified GHRH analogue without the albumin-binding Drug Affinity Complex. It has a longer half-life than sermorelin but shorter than CJC-1295 with DAC, and is the most commonly supplied version by research peptide vendors.
What is tesamorelin research peptide?
Tesamorelin is a stabilised GHRH analogue with an added trans-3-hexenoic acid group that protects against enzymatic degradation. It is the only currently FDA-approved GHRH analogue, approved for a specific HIV-related lipodystrophy indication.
Why is CJC-1295 combined with ipamorelin in research?
Because they act on different receptor pathways — GHRH-R and GHSR-1a respectively — their combination produces additive or synergistic GH secretory effects in animal models. Published research has studied this dual-pathway approach as a way to maximise pituitary GH stimulation in preclinical settings.
This article summarises published peer-reviewed research and is provided for informational purposes only. Neurovia’s peptides are supplied for laboratory research use only and are not intended for human consumption. Full disclaimer →
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