Overview
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In plain language
GHRP-6 is a lab-made peptide of 6 amino acids that makes the body release growth hormone. It was one of the first compounds of its kind, made in the 1980s.
It acts on the ghrelin receptor, the same switch used by the body's "hunger hormone," so it also strongly increases appetite. It is not FDA-approved in the United States, and it is banned in sport.
For students
GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, about 873 Da) was reported by Bowers and colleagues in 1984 as a potent GH-releasing hexapeptide derived from earlier enkephalin analogues.
It activates GHS-R1a, synergizes with GHRH to release growth hormone, and is reported to stimulate appetite more strongly than GHRP-2. Its discovery led to non-peptide secretagogues such as ibutamoren (MK-677) and to the cloning of the receptor that ghrelin was later found to activate.
For researchers and instructors
Pharmacology. GH release is dose-dependent and pulsatile; responses are blunted with continuous exposure. Modest increases in cortisol and prolactin occur.
Research use. Studied in models of cardioprotection and as a pharmacological tool for GHS-R biology.
Regulatory and sport. Not FDA-approved. Prohibited by WADA.
Molecular identity
- Amino acids
- 6
- Molecular weight
- ~873.0 Da
- Formula
- Form-dependent; verify
- Sequence
- His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂
Origin and history
In the late 1970s Cyril Bowers at Tulane University, working with computational chemist Frank Momany, modified opioid peptides called enkephalins and stumbled on small peptides that made the pituitary release growth hormone. In 1984 they published GHRP-6, a six-amino-acid peptide.
It worked through an unknown receptor. Merck scientists cloned that receptor in 1996, and in 1999 Masayasu Kojima and Kenji Kangawa in Japan found the body’s own hormone for it: ghrelin, the “hunger hormone” made in the stomach. GHRP-6 is a classic case of a drug leading scientists to a natural hormone.
Key people
- Cyril Y. BowersTulane University
- Frank MomanyComputational chemist
- Masayasu Kojima & Kenji KangawaDiscovered ghrelin (1999)
Timeline
- 1984
GHRP-6 published
- 1996
Its receptor (GHS-R) cloned at Merck
- 1999
Ghrelin discovered as the natural hormone for the receptor
See every peptide on one history timeline.
Human evidence
Human hormone-response studies exist, but long-term therapeutic outcomes remain unproven.
Study design, enrollment, endpoints, outcomes and limitations must be assessed individually; registration is not proof of efficacy.
Explore the literature for GHRP-6 and distinguish in-vitro, animal, and human findings.
Safety and regulatory status
See every compound on the regulatory tracker.
Not FDA-approved for human therapeutic use in the United States.
Long-term risks, formulation differences, and human safety evidence require careful review. Educational content only; not medical advice.
Sources
Hernandez Gener, E. (2026, November 7). GHRP-6: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/ghrp-6.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy