GHRP-6
From PeptidePlaza, the free peptide reference · Entry #025 · Recovery · Hand-curated entry · Editorial standards
GHRP-6 (also known as GHRP6, Hexapeptide, GH-releasing hexapeptide) is a recovery research peptide. A synthetic ghrelin-mimetic hexapeptide that potently stimulates GH release through the ghrelin receptor. One of the first growth hormone secretagogues developed, with over 25 years of research history.
GHRP-6 is a synthetic hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) developed in the 1980s as a growth hormone secretagogue. It acts as a ghrelin receptor (GHS-R1a) agonist, potently stimulating pituitary GH release and amplifying GH pulse amplitude. Beyond its endocrine effects, research has explored its cytoprotective and tissue-repair actions, including cardioprotection, wound healing, and organ-protective effects in ischemia models. It was the first GHRP to reach clinical testing and remains a widely studied reference compound in GH research.
1 Mechanism of action
Binds the growth hormone secretagogue receptor (GHS-R1a), activating phospholipase C and intracellular calcium release, leading to GH exocytosis from pituitary somatotrophs. Also activates hypothalamic GHRH neurons and suppresses somatostatin tone.
Primary targets: GHS-R1a (ghrelin receptor)
2 Reported effects
Effects below are those reported in the published literature cited on this page. They are not claims of clinical benefit and not medical advice.
2.1 Reported benefits
- Potent GH release in clinical and preclinical studies
- Amplifies endogenous GH pulse amplitude
- Cardioprotective effects in ischemia models
- Tissue-repair and organ-protection research
2.2 Side effects
- Marked appetite stimulation (ghrelin agonism)
- Cortisol and prolactin elevation at higher doses
- Transient blood pressure changes
- Injection site reactions
3 Chemical and physical properties
| CAS number | 87616-84-0 |
|---|---|
| Molar mass | 872.0 g/mol |
| Purity (typical) | >99% |
| Half-life | ~20–30 minutes |
| Storage | −20 °C, lyophilised powder, desiccated |
| Solubility | Sterile water / bacteriostatic water |
| Receptors / targets | GHS-R1a (ghrelin receptor) |
3.1 Amino acid sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
4 Research dosages
100–300 μg SC, 1–3× daily in common research protocols.
5 Research studies (6)
- Growth hormone releasing peptide-6 (GHRP-6) prevents doxorubicin-induced myocardial and extra-myocardial damages by activating prosurvival mechanisms.
Frontiers in pharmacology (2024) · Review - Use of growth-hormone-releasing peptide-6 (GHRP-6) for the prevention of multiple organ failure.
Clinical science (London, England : 1979) (2006) · ReviewNovel therapies for the treatment of MOF (multiple organ failure) are required. - Growth hormone-releasing peptide (GHRP).
Cellular and molecular life sciences : CMLS (1998) · ReviewGrowth hormone-releasing peptides and non-peptides (GHRPs. - Growth hormone releasing hexapeptide-6 (GHRP-6) test in the diagnosis of GH-deficiency.
Journal of pediatric endocrinology & metabolism : JPEM (1996) · ReviewPituitary GH reserve can be assessed by substances that act directly at the somatotroph, such as GHRH, or by a variety of metabolic and neuropharmacological tests acting at the hypothalamic level, such as... - Growth hormone responses to GH-releasing peptide (GHRP-6) in hypothyroidism.
Clinical endocrinology (1997) · ReviewOBJECTIVE: Both spontaneous and stimulated GH secretion are reduced in patients with hypothyroidism. - Growth hormone-releasing peptide 6 (GHRP-6) hydrogel for acute kidney injury therapy via metabolic regulation.
Journal of nanobiotechnology (2025) · ReviewRenal tubular epithelial cells (TECs), which are highly susceptible to injury during acute kidney injury (AKI), have notable regenerative effects on renal recovery after AKI.
6 Safety and risk profile
6.1 Regulatory status
GHRP-6 is currently classified as Not approved. It has no approved human indication in the United States; availability elsewhere does not imply demonstrated safety or efficacy.
Safety score: 45/100 — moderate concern. Derived from clinical data volume, known risks and regulatory status.
6.2 Contraindications
Conditions and populations in which use is contraindicated:
- Pregnancy or lactation
- Active malignancy
- Prolactinoma or hyperprolactinemia
6.3 Drug interactions
| Drug or class | Interaction | Risk |
|---|---|---|
| Dopamine antagonists | May enhance prolactin elevation. | Moderate |
| Somatostatin analogs | Blunt GHRP-stimulated GH release. | High |
| Other GH secretagogues | Potential additive GH release; design protocols carefully. | Moderate |
6.4 Long-term risks
- Chronic GH elevation may promote insulin resistance
- Prolactin elevation with frequent dosing
- Growth-factor-sensitive tumor risk
6.5 Research best practices
- Store lyophilized at −20 °C
- Reconstitute with bacteriostatic water; use within 2 weeks refrigerated
- Dose on an empty stomach for more consistent GH response
- Monitor cortisol and prolactin in longer protocols
7 Frequently asked questions
- How does GHRP-6 increase growth hormone?
- GHRP-6 is a ghrelin mimetic that binds the GHS-R1a receptor, directly stimulating pituitary GH release and amplifying the amplitude of GH pulses — typically producing a large GH spike within 15–30 minutes of dosing.
- What else is GHRP-6 studied for?
- Beyond GH release, animal studies have examined GHRP-6 for cardioprotection after ischemia, organ protection in multiple organ failure, and improved wound/tissue healing.
- How is it typically dosed in research?
- Common research protocols use 100–300 μg per dose, 1–3 times daily, subcutaneously. The classic hunger-stimulating effect (ghrelin agonism) is a common reported side effect.
8 References
- Growth hormone releasing peptide-6 (GHRP-6) prevents doxorubicin-induced myocardial and extra-myocardial damages by activating prosurvival mechanisms. PubMed (2024). Berlanga-Acosta J, et al.. View source
- Use of growth-hormone-releasing peptide-6 (GHRP-6) for the prevention of multiple organ failure. PubMed (2006). Cibrián D, et al.. View source
- Growth hormone-releasing peptide (GHRP). PubMed (1998). Bowers CY, et al.. View source
- Growth hormone-releasing peptide 6 (GHRP-6) hydrogel for acute kidney injury therapy via metabolic regulation. PubMed (2025). Zhao X, et al.. View source
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