GHRP-6
experimentalAlso known as: Growth Hormone Releasing Peptide-6
**Mechanism of Action** GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that acts as a first-generation agonist of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R1a). By binding to this receptor, it mimics the endogenous hormone ghrelin, leading to activation of the GHS-R1a in the pituitary gland and hypothalamus. This triggers a downstream signaling cascade that stimulates the release of growth hormone (GH) from somatotroph cells, independent of growth hormone-releasing hormone (GHRH). Additionally, GHRP-6 potently increases appetite via central mechanisms, likely through modulation of neuropeptide Y (NPY) and agouti-related peptide (AgRP) in the arcuate nucleus. **Key Research Findings** Preclinical studies demonstrate that GHRP-6 induces a robust, dose-dependent rise in serum GH levels in both animal models and human subjects, with effects peaking within 15–30 minutes of administration. Its orexigenic (appetite-stimulating) properties are well-documented, with research showing significant increases in food intake and body weight in cachectic or underweight subjects. However, its clinical utility is limited by rapid desensitization of the GHS-R1a upon repeated dosing, leading to diminished GH responses over time. Experimental studies have also explored its potential in conditions like muscle wasting, aging-related sarcopenia, and GH deficiency, but robust human efficacy data remain scarce. **Clinical Relevance** GHRP-6 remains an experimental compound with no approved therapeutic indications. Its strong appetite-stimulating effect has been investigated for cachexia and anorexia, but safety concerns—including potential for hyperprolactinemia, cortisol elevation, and tachyphylaxis—restrict its clinical translation. Current research focuses on optimizing dosing regimens or combining it with GHRH analogs to sustain GH release. Without large-scale, long-term human trials, its risk-benefit profile is poorly defined. For research purposes only — not medical advice.
Key data
C46H56N12O6Research & studies
GHRP-6 reduced neutrophilic alveolitis and attenuated lung compliance failure in acute lung injury models.; GHRP-6 improved alveolar-capillary permeability and decreased interleukin-1 beta serum levels.; In the chronic scenario, GHRP-6 preserved lung parenchymal integrity with minimal collagen accumulation.; This is the first assessment of GHRP-6's protective potential in lung damage models.
GHRP-6 hydrogel treatment enriched spermidine, L-glutamine, and acetyl-CoA in AKI mouse kidneys.; The hydrogel enhanced survival of renal tubular epithelial cells in ischemic conditions.; Metabolic reprogramming via mTOR-P70 pathway activation was identified as the mechanism.; GHRP-6 hydrogel offers a novel therapeutic strategy for protecting tubular cells in AKI.
Calorie restriction increases chromogranin A-positive and ghrelin+ cells in the mouse stomach.; This effect is accompanied by increased Notch target Hes1 and ligand Jag1, and is reversed by Notch inhibition with DAPT.; Calorie restriction decreases gastric Lgr5+ stem cells but increases a FOXO1/Neurog3+ endocrine progenitor subpopulation in a Notch-dependent manner.; Notch inhibitor PF-03084014 or ghrelin receptor antagonist GHRP-6 reverses the phenotypic effects of calorie restriction in mice.
GHRP-6 prevented myocardial fiber loss and ventricular dilation, preserving LV systolic function.; GHRP-6 attenuated extra-cardiac damage, preserving epithelial organ integrity and reducing fibrosis.; GHRP-6 sustained cellular antioxidant defense and upregulated the prosurvival gene Bcl-2.; GHRP-6 preserved cardiomyocyte mitochondrial integrity and reduced morbidity and mortality.
GHS are potent GH and IGF-1 stimulators that can improve body composition and reduce fat gain and muscular atrophy.; Testosterone remains the gold standard for hypogonadism, but its benefits on body composition are not consistent across all populations.; Current data on the clinical efficacy of GHS are lacking, limiting understanding of their role in treatment.; GHS may have a complementary role in managing hypogonadal and eugonadal males with metabolic syndrome or subclinical hypogonadism.
Six metabolites of GHRP-1 were identified; parent GHRP-1 was not detected, but GHRP-1 (2-4) free acid was found up to 27 hours.; GHRP-2, its free acid, and GHRP-2 (1-3) free acid were detectable up to 47 hours post-administration.; GHRP-6 was mostly excreted unchanged and detected for 23 hours, with metabolites only detectable for 12 hours.; Hexarelin and Ipamorelin were extensively metabolized, with metabolites like Hexarelin (1-3) free acid and Ipamorelin (1-4) free acid persisting after parent compounds were undetectable.
[D-Lys3]-GHRP-6 increased beclin-1 protein and LC3 II-to-I ratio in normal and doxorubicin-injured muscle.; It reduced doxorubicin-induced muscle apoptosis and prevented centronucleated fiber increase.; No histological abnormalities were observed in treated muscle.; Pro-autophagic effects were abolished by CXCR4 antagonist, suggesting CXCR4 mediation.
Frequently asked questions
What is GHRP-6?
**Mechanism of Action** GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that acts as a first-generation agonist of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R1a). By binding to this receptor, it mimics the endogenous hormone ghrelin, leading to activation of the GHS-R1a in t
How does GHRP-6 work?
First-generation ghrelin receptor agonist hexapeptide that stimulates GH release and strongly increases appetite.
What is the research status of GHRP-6?
GHRP-6 is currently classified as experimental, with 636 research references on record. This is for research purposes only and is not medical advice.
What is the molecular weight of GHRP-6?
GHRP-6 has a molecular weight of approximately 873 g/mol (formula C46H56N12O6).
Related peptides
Endogenous cyclic peptide that inhibits GH, insulin, glucagon, and gastric secretion via SSTR1-5 receptors.
Endogenous 28-aa 'hunger hormone' from the stomach; activates GHS-R1a to stimulate GH release and appetite.
Potent GHRP-family ghrelin receptor agonist with studied cardioprotective effects independent of GH release.
Synthetic hexapeptide ghrelin receptor agonist that potently stimulates GH secretion; also raises appetite, cortisol, and prolactin.
Stabilized GHRH analog approved for HIV-associated lipodystrophy; reduces visceral adipose tissue via GH/IGF-1 axis stimulation.
Selective ghrelin receptor (GHS-R1a) agonist that stimulates GH release with minimal effect on cortisol or prolactin.
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