GHRP-6
In clinical trialsAppetite-stimulating GH releasing peptide
Also known as: Growth Hormone Releasing Peptide-6, SKF-110679
GHRP-6 is one of the original growth hormone releasing peptides, notable for producing the strongest appetite stimulation of the GHRP family alongside its GH-releasing effect.
Molecular & research data
- Sequence
- His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
- CAS number
- 87616-84-0
- Molecular formula
- C46H56N12O6
- Molecular weight
- 873.01 g/mol
- Half-life
- ≈15–60 minutes
- Primary targets
- GHS-R1a (ghrelin receptor)
- Routes (research)
- Subcutaneous
- Storage
- Lyophilised: −20 °C. Reconstituted: 2–8 °C, use within weeks.
Overview
GHRP-6 is one of the original growth hormone releasing peptides and a foundational tool in the discovery of the ghrelin signalling system. Among the GHRP family it is best known for one distinctive property: it produces the strongest appetite stimulation.
Mechanism of action
GHRP-6 binds the GHS-R1a (ghrelin) receptor, stimulating growth hormone release. Because this receptor also governs hunger signalling, GHRP-6 produces a marked increase in appetite — a useful research property in some contexts and an unwanted side effect in others. It can also raise cortisol and prolactin.
This places it at the opposite end of the selectivity spectrum from Ipamorelin, and makes it a frequent point of comparison with the more potent, less hunger-inducing GHRP-2.
Common research uses
- Research into ghrelin signalling and appetite regulation
- Stimulated growth hormone release studies
- As the reference “appetite-stimulating” GHRP in family comparisons
Compare GHRP-6
GHRP-6 FAQ
Why is GHRP-6 known for hunger?+
As a ghrelin mimetic it strongly activates the appetite-signalling role of the ghrelin receptor, producing pronounced hunger — more than GHRP-2 and far more than the selective Ipamorelin.
How potent is GHRP-6 at releasing GH?+
It is an effective GH releaser, though generally considered less potent than GHRP-2 and Hexarelin. Its appetite effect is its most distinctive feature.
Is GHRP-6 selective?+
No. Along with GH release it stimulates appetite and can raise cortisol and prolactin, making it the least selective of the commonly studied GHRPs.
References
Related peptides
GHRP-2
In clinical trialsPotent ghrelin-mimetic GH secretagogue
GHRP-2 (pralmorelin) is a potent growth hormone releasing peptide used clinically as a diagnostic agent in some countries, known for strong GH release with moderate appetite and cortisol effects.
Ipamorelin
In clinical trialsSelective ghrelin-mimetic GHRP
Ipamorelin is a selective growth hormone releasing peptide (GHRP) that stimulates GH release with minimal effect on cortisol, prolactin, or appetite, making it the cleanest of the classic GHRPs.
Hexarelin
In clinical trialsHighly potent GHRP with cardiac research interest
Hexarelin is among the most potent growth hormone releasing peptides and is distinguished by additional research interest in cardiac tissue via the CD36 receptor, though it is prone to receptor desensitisation.
Last reviewed: 2026-06-26. Information is provided for research and educational reference only — see our disclaimer.