GHRP-6 (Growth Hormone Releasing Peptide-6)

What is GHRP-6?

GHRP-6 is a synthetic hexapeptide growth hormone secretagogue with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 that acts as an agonist at the ghrelin receptor (growth hormone secretagogue receptor, GHSR-1a). It was one of the earliest met-enkephalin-derived secretagogues, developed before ghrelin itself was identified, and its discovery led directly to the cloning of the GHSR.

Unlike GHRH analogues such as sermorelin, GHRP-6 stimulates GH release through a separate receptor pathway and also produces ghrelin-like effects on appetite signalling, gastric motility and cortisol and prolactin release in animal models. This broader profile makes GHRP-6 a widely used tool compound in neuroendocrine research.

GenoPept supplies GHRP-6 in the UK as a lyophilised research peptide in 5mg and 10mg vials, each batch verified by independent HPLC and LC-MS analysis and supplied for laboratory research only.

GHRP-6 research applications

Ghrelin receptor pharmacology

GHRP-6 is a standard agonist in GHSR-1a binding and functional assays, used to map receptor signalling, desensitisation and the pharmacology of newer secretagogues.

GH secretion and synergy studies

Animal and pituitary cell models use GHRP-6 to study GH release and its synergy with GHRH analogues, since the two pathways act through different receptors.

Appetite and gastric motility

Because it mimics ghrelin, the peptide is studied in feeding behaviour and gastrointestinal motility models in rodents.

Cardiovascular and cytoprotection models

Published preclinical research has investigated it in models of myocardial ischaemia and tissue injury, exploring GHSR-independent binding to CD36.

Neuroendocrine stress axis

GHRP-6 raises cortisol and prolactin in animal models, providing a tool for studying secretagogue cross-talk with the hypothalamic-pituitary-adrenal axis.

Mechanism of action (preclinical)

GHRP-6 binds the ghrelin receptor GHSR-1a, a Gq-coupled receptor on pituitary somatotrophs and hypothalamic neurons. Activation triggers phospholipase C, inositol trisphosphate signalling and calcium release, which stimulates GH exocytosis. GHRP-6 also acts in the hypothalamus to promote GHRH release and reduce somatostatin tone.

In preclinical models, combining this secretagogue with a GHRH analogue produces a greater GH response than either alone, reflecting the two independent receptor systems. GHRP-6 is less selective than ipamorelin and also increases circulating cortisol, prolactin and appetite signalling, which is relevant to experimental design.

GHRP-6 product specifications

Available sizes

• 5mg vial
• 10mg vial

Laboratories running larger studies can order bulk boxes of 10 vials, which save 20-50% against single-vial pricing; see the bulk and wholesale page. Orders over £200 ship free by tracked Royal Mail Special Delivery within the UK.

Reconstitution, handling and storage (laboratory)

GHRP-6 is supplied as a lyophilised powder that is stable for long-term storage at -20 °C. Unopened vials may be kept at 2-8 °C for short periods, protected from light. Allow a vial to reach room temperature before opening to avoid condensation on the powder.

For reconstitution, add bacteriostatic water or a sterile diluent slowly down the inside wall of the vial, then swirl gently until the powder dissolves. Never shake a peptide vial, because mechanical stress can damage the molecule and reduce measured purity.

After reconstitution, keep the solution at 2-8 °C and use it within the period stated in your laboratory protocol. Full guidance is available in our articles on how to reconstitute research peptides and how to store research peptides.

Quality assurance and Certificate of Analysis

Every batch of GHRP-6 sold by GenoPept is tested by an independent ISO/IEC 17025 laboratory (Puralytix). HPLC confirms purity of 99% or higher and LC-MS confirms molecular identity, so the compound in the vial matches the label.

Each product page carries a “View Certificate of Analysis” button, and the complete library is published at genopept.co.uk/coa-certificates. Vials are batch-identified with lot number and expiry date, and our guide to what a Certificate of Analysis shows explains how to read the report.

Related research compounds

• GHRP-2 (Pralmorelin): a more potent hexapeptide secretagogue from the same GHRP family.
• Ipamorelin: a selective pentapeptide GHSR agonist with reduced cortisol and prolactin effects in models.
• Hexarelin: a methylated GHRP-6 analogue studied in cardiovascular models.
• CJC-1295 No DAC (Modified GRF 1-29): a GHRH analogue often co-investigated with GHRPs for synergy studies.

GHRP-6 frequently asked questions

What is GHRP-6 used for in research?

GHRP-6 is used as a reference ghrelin receptor agonist in laboratory research. Typical applications include GHSR-1a receptor assays, pituitary GH release experiments, synergy studies with GHRH analogues, and rodent models of appetite, gastric motility and myocardial protection. Its wide activity profile makes it a useful comparator for more selective secretagogues. Supplied strictly for in-vitro laboratory research.

How is GHRP-6 supplied and what purity does it have?

GenoPept GHRP-6 is supplied as a lyophilised powder in sealed, sterile glass vials of 5mg or 10mg. Each batch is analysed by an independent ISO/IEC 17025 laboratory using HPLC for purity, which must be 99% or higher, and LC-MS to confirm molecular identity. The batch Certificate of Analysis is available on the product page and in our COA library.

How should GHRP-6 be stored in the laboratory?

Store unopened lyophilised GHRP-6 at -20 °C for long-term stability, or at 2-8 °C for short periods away from light. After reconstitution with bacteriostatic water, keep the solution at 2-8 °C and use it within the timeframe defined in your laboratory protocol. Add diluent slowly down the vial wall, swirl gently, and never shake.

Is GHRP-6 for human use?

No. GHRP-6 from GenoPept is a research compound supplied for in-vitro laboratory use only. It is not a medicine, is not for human or veterinary use, and is not intended for diagnostic or therapeutic purposes. GenoPept does not provide dosing or administration guidance and requires that purchasers are buying for legitimate research within the UK.

What is the difference between GHRP-6 and GHRP-2?

Both are synthetic hexapeptide agonists of the ghrelin receptor, but they differ in sequence and potency. GHRP-2 (pralmorelin) contains a D-2-naphthylalanine residue and produces a stronger GH release in animal models, while GHRP-6 shows a more pronounced ghrelin-like effect on appetite signalling. Both increase cortisol and prolactin in preclinical models, unlike the more selective ipamorelin.

Research use only. This product is supplied for in-vitro laboratory research only. It is not for human or veterinary use, not a medicine, and not for diagnostic or therapeutic use. See our research use only policy and UK legal guide.