GH Secretagogue Peptide Class / GHRP Family / Ghrelin Mimetic Research Compounds
GHRP Peptides — Growth Hormone Secretagogue Research Compounds Comparison
GHRP peptides (Growth Hormone Releasing Peptides) are a class of synthetic ghrelin-receptor agonists (GHS-R1a) that stimulate pituitary growth hormone (GH) release via a mechanism distinct from GHRH. The GHRP class was discovered before ghrelin and actually predicted its existence: GHRPs bind the ghrelin receptor (GHS-R1a) to amplify pulsatile GH secretion. The four primary GHRP class peptides in active research — Hexarelin, GHRP-2 (pralmorelin), GHRP-6, and Ipamorelin — differ substantially in potency, selectivity, peripheral binding, and cardiovascular effects, making compound selection a critical variable in secretagogue peptide research design.
Compound identity
- Name
- GHRP Peptides — Research Comparison Hub
- Class
- GH Secretagogue Peptide Class / GHRP Family / Ghrelin Mimetic Research Compounds
- Also known as
- GHRP peptide research, growth hormone releasing peptide, hexarelin vs GHRP-2, GHRP-6 vs GHRP-2, best GHRP peptide, GHRP comparison, secretagogue peptide comparison, ipamorelin vs hexarelin, GHRP class peptides
Research context
The GHRP family shares a common primary mechanism: agonism at GHS-R1a (the ghrelin receptor, a 7-TM Gi/Gq-coupled GPCR expressed on pituitary somatotrophs and hypothalamic neurons). GHS-R1a activation triggers Gq-coupled PKC/IP3 signaling and intracellular Ca²⁺ release, depolarizing somatotrophs and amplifying pulsatile GH secretion. All GHRP compounds also act synergistically with endogenous GHRH — GHRPs amplify GH release, but peak response requires intact GHRH input (the two pathways are additive/synergistic). The four compounds have well-characterized but distinct binding profiles: Hexarelin (His-D-2MeTrp-Ala-Trp-D-Phe-Lys-NH₂, MW 887.06 Da, CAS 140703-51-1) is the most potent synthetic GHS-R1a agonist with an additional CD36 cardioprotective binding site not shared by the others; GHRP-2 (pralmorelin; MW 817.97 Da; CAS 158861-67-7) is high-potency and was approved in Japan as a GH deficiency diagnostic; GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂, MW 873.02 Da, CAS 87616-84-0) was the first GHRP discovered and is notable for strong appetite/ghrelin-axis stimulation; Ipamorelin (Aib-His-D-2MeTrp-D-Phe-Lys-NH₂, MW 711.86 Da, CAS 170851-70-4) is the most GH-selective GHRP with minimal effect on cortisol, prolactin, or ACTH at research doses.
Key comparative research parameters across GHRP compounds: **Potency (GH release per molar dose):** Hexarelin > GHRP-2 > GHRP-6 > Ipamorelin. **Selectivity (GH vs cortisol/prolactin stimulation):** Ipamorelin (high selectivity, minimal cortisol/prolactin) > GHRP-2 > GHRP-6 > Hexarelin (stimulates cortisol, prolactin, and ACTH in parallel with GH). **Cardiovascular effects:** Hexarelin has unique cardioprotective effects via CD36 binding (cardioprotection in ischemia models, myocardial survival independent of GH axis) — unique to Hexarelin; not a class effect. **Appetite stimulation (ghrelin axis):** GHRP-6 > Hexarelin > GHRP-2 > Ipamorelin (Ipamorelin has the least appetite/orexigenic effect). **Receptor desensitization with chronic exposure:** GHRP-6 > GHRP-2 > Hexarelin > Ipamorelin (Ipamorelin desensitizes most slowly in chronic administration models). These differences make compound selection a critical experimental design decision in GHRP research.
Published research applications across the GHRP class include: GH axis characterization and GHRH-synergy studies (all four GHRPs); body composition research in GH-deficient animal models (GHRP-2 / pralmorelin extensively in clinical and pre-clinical settings; Japan-approved diagnostic); cardiac ischemia and cytoprotection research (Hexarelin specifically, via CD36 binding); neuroprotection and aging research (all GHRPs, especially Hexarelin and GHRP-2); IGF-1 axis research (GH → liver IGF-1 production; all GHRPs elevate IGF-1 in animal models via GH axis activation); and appetite/metabolic axis research (GHRP-6 and ghrelin-pathway studies). DMV Research supplies Hexarelin, GHRP-2, GHRP-6, and Ipamorelin as individual research compounds, each with per-batch Certificate of Analysis. For GHRP + GHRH combinatorial research, CJC-1295 (a GHRH analog) is also available in the DMV Research compound library.
Frequently asked questions
What are GHRP peptides?+
GHRP (Growth Hormone Releasing Peptide) peptides are synthetic agonists of the GHS-R1a receptor (the ghrelin receptor), stimulating pituitary GH release independently of GHRH. The four primary GHRP class research compounds are: Hexarelin (most potent, has additional CD36 cardiac binding), GHRP-2 / pralmorelin (high potency, clinical diagnostic in Japan), GHRP-6 (first discovered, strong appetite stimulation), and Ipamorelin (most GH-selective, minimal cortisol/prolactin effect). All are supplied by DMV Research as research compounds for in-vitro and pre-clinical laboratory research use only.
How does Hexarelin compare to GHRP-2 and GHRP-6 in research?+
Potency ranking: Hexarelin > GHRP-2 > GHRP-6. Hexarelin is the most potent GHS-R1a agonist in the class, but also the least selective — it significantly stimulates cortisol, ACTH, and prolactin alongside GH. Hexarelin's unique property is dual binding: GHS-R1a (GH secretagogue) AND CD36 (cardioprotective, GH-independent). GHRP-2 (pralmorelin) is nearly as potent as Hexarelin and was approved in Japan as a GH deficiency diagnostic. GHRP-6 is moderately potent and notable for pronounced ghrelin-axis appetite stimulation (the strongest among the four). For GH-focused, minimal-off-target research, Ipamorelin is often preferred; for cardiac/GH dual-axis research, Hexarelin is the compound of interest.
What makes Ipamorelin different from other GHRPs?+
Ipamorelin (Aib-His-D-2MeTrp-D-Phe-Lys-NH₂, MW 711.86 Da) is distinguished by exceptional GH selectivity — at research doses that stimulate significant GH release, Ipamorelin produces minimal to no measurable cortisol, ACTH, or prolactin stimulation, unlike Hexarelin, GHRP-2, and GHRP-6. It also desensitizes the GHS-R1a receptor most slowly among the four GHRPs in chronic administration models. This selectivity makes Ipamorelin a preferred tool for isolating GH axis effects from HPA axis effects in research designs. The tradeoff vs Hexarelin: lower absolute potency and no CD36 cardiac activity. For GHRH-synergy research, Ipamorelin + CJC-1295 is the most commonly published combination in contemporary peptide research literature.
Are GHRP peptides available at DMV Research?+
Yes. DMV Research carries all four primary GHRP research compounds — Hexarelin, GHRP-2, GHRP-6, and Ipamorelin — as individual lyophilized research peptides with per-batch Certificate of Analysis confirming identity by mass spectrometry and purity ≥99% by HPLC. All are supplied for in-vitro and pre-clinical laboratory research use only — not for human consumption. CJC-1295 (a GHRH analog, synergistic with all GHRPs) is also available in the DMV Research compound library.
Research use only
All products are intended for laboratory and research use only (RUO) and are not for human consumption, ingestion, or any in-vivo use.
The statements on this page have not been evaluated by the FDA. GHRP Peptides — Research Comparison Hub is not intended to diagnose, treat, cure, or prevent any disease. Content is provided for laboratory research reference only.