Summary
GHRP-6 is a synthetic hexapeptide described by Cyril Bowers in 1984 that releases growth hormone through what was later identified as the ghrelin receptor. It strongly increases appetite and also raises cortisol and prolactin.
Structure
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. One of the first synthetic GH secretagogues, designed before ghrelin itself was discovered.
How it works
GHRP-6 activates GHS-R1a. Its discovery led to the receptor’s cloning in 1996 and, in 1999, to the identification of ghrelin as the natural ligand.
Research use cases
Areas where GHRP-6 has been studied. Inclusion here does not mean it works for that purpose.
- GH secretion physiology
- Appetite regulation
- Cardioprotection in animal models
What the research found
Original description
Bowers and colleagues showed that the hexapeptide specifically released GH from pituitary cells in vitro and in animals.1
Safety and open questions
Increased hunger, raised cortisol and prolactin, and water retention are reported. Not studied in long-term controlled trials.
Regulatory status
Not approved. Prohibited by WADA (S2). Remains in FDA compounding Category 2.
Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.
GHRP-6: common questions
Why does GHRP-6 cause hunger?
It activates the same receptor as ghrelin, the body’s main hunger hormone.
Is GHRP-6 approved for human use?
Not approved. Prohibited by WADA (S2). Remains in FDA compounding Category 2.
References
- Bowers CY, Momany FA, Reynolds GA, Hong A. (1984). On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology.
Links open a PubMed search for the exact title, or the original source where one is given.