Growth-Hormone Secretagogue Research Peptides: A Complete Overview

These materials are research-grade reference compounds sold for laboratory research use only. They are not for human or veterinary use.

Growth-hormone secretagogue is an umbrella term for peptides studied in relation to the growth-hormone axis. The category is easy to misread as one group of similar molecules, but it actually contains two distinct research classes that act on two different receptors: analogs of growth-hormone-releasing hormone (GHRH) and growth-hormone-releasing peptides (GHRPs). This overview explains the two-class structure, maps the individual compounds, and links to each reference page and comparison article.

At a Glance

• Two classes: GHRH analogs and GHRPs (ghrelin-receptor agonists).
• GHRH analogs include sermorelin, tesamorelin, and CJC-1295.
• GHRPs include GHRP-2, GHRP-6, hexarelin, and ipamorelin.
• The classes act on different receptors and are often studied together to examine both.
• All are research chemicals for laboratory use only.

The Two Secretagogue Classes

GHRH analogs

GHRH analogs are based on growth-hormone-releasing hormone and act at the GHRH receptor, a class B G-protein-coupled receptor. Sermorelin represents the minimal active GHRH(1-29) fragment; tesamorelin and CJC-1295 are modified analogs engineered for greater stability, with the CJC-1295 DAC version studied for extended half-life through albumin binding (Teichman et al., 2006).

Growth-hormone-releasing peptides (GHRPs)

GHRPs are short synthetic peptides that act at the ghrelin/growth-hormone-secretagogue receptor, GHS-R1a. The GHRP series was historically central to the discovery of that receptor and its natural ligand, ghrelin (Bowers, 2012; Kojima et al., 1999). Ipamorelin, characterized as the first selective GHRP (Raun et al., 1998), sits in this class alongside GHRP-2, GHRP-6, and hexarelin.

Members Mapped

Compound	Class	Reference
Sermorelin	GHRH analog	See reference page
Tesamorelin	GHRH analog	Reference page
CJC-1295	GHRH analog	Reference page
Ipamorelin	GHRP	Reference page
GHRP-6	GHRP	See reference page
GHRP-2	GHRP	See reference page
Hexarelin	GHRP	Reference page

Why the Two Classes Are Studied Together?

Because GHRH analogs and GHRPs act on different receptors within the same axis, they are frequently paired in research designs to examine both arms at once. This is the basis for the common comparison articles, such as CJC-1295 versus ipamorelin and tesamorelin versus ipamorelin, each of which pairs a GHRH analog with a GHRP.

Shared Themes in the Literature

Across the category, research focuses on receptor binding and signaling, selectivity within the growth-hormone axis, and peptide stability, using animal and cell-based systems. Ipamorelin is noted for selectivity (Raun et al., 1998); CJC-1295 for engineered stability (Teichman et al., 2006); and the GHRP series for its historical role in ghrelin research (Bowers, 2012). These are mechanistic and model observations, not statements about human use.

How the Class Is Studied

Research uses receptor-binding and signaling assays, animal models of the growth-hormone axis, and structure-activity studies comparing family members. Selectivity and stability are recurring experimental variables.

Chemical Identity and Verification

Each secretagogue is verified by HPLC for purity and mass spectrometry for identity, documented on the per-lot Certificate of Analysis. Identity data differ by compound and should be read from each COA.

Handling and Documentation

Store sealed material cold, shield it from light, and avoid repeated freeze-thaw. Lot-specific stability is documented on the COA; current lot reports are on the Lab Reports page.

Research Limitations and Open Questions

The secretagogue literature is built largely on animal and cell models, so findings do not translate directly to any human context. Direct, identical-condition comparisons across the family are less common than single-compound studies, which is worth noting when weighing relative selectivity or stability claims.

Frequently Asked Questions

What is a growth-hormone secretagogue peptide?

A peptide studied in relation to the growth-hormone axis, either as a GHRH analog or as a GHRP (ghrelin-receptor agonist).

What is the difference between GHRH analogs and GHRPs?

They act at different receptors: the GHRH receptor versus the ghrelin/growth-hormone-secretagogue receptor.

Which peptides fall in each group?

GHRH analogs: sermorelin, tesamorelin, CJC-1295. GHRPs: GHRP-2, GHRP-6, hexarelin, ipamorelin.

Why are the two classes paired in studies?

Because they engage two different receptors within the same axis, pairing them lets researchers examine both arms together.

Which is the most selective GHRP?

Ipamorelin was characterized as the first selective growth-hormone secretagogue in its founding report (Raun et al., 1998).

How are they verified?

By HPLC and mass spectrometry, documented on the per-lot Certificate of Analysis.

Do these findings apply to people?

No. All cited work is in animal or cell models and describes mechanism and research outcomes only.

Related Reading

• CJC-1295 vs Ipamorelin; Tesamorelin vs Ipamorelin; GHRP-6 vs GHRP-2 (comparison articles)
• GH-Releasing Peptides (GHRP family) overview
• Lab Reports

References

1. Bowers CY. History to the discovery of ghrelin. Methods Enzymol. 2012. PMID 22975043.
2. Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. PMID 9849822.
3. Teichman SL, et al. Prolonged stimulation of growth hormone by CJC-1295. J Clin Endocrinol Metab. 2006. PMID 16352683.
4. Kojima M, et al. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999. PMID 10604470.

Research-use notice: These peptides are research chemicals sold for laboratory research use only. They are not for human or veterinary use. Every finding is reported in the specific research context of the cited study.