GHRP-6
Growth hormone secretagogue (ghrelin receptor agonist)
Status
Not approved
Never approved for human use anywhere; FDA lists it in 503B Category 2 (significant safety risks, 2023) and 503A Category 3 (nominated without adequate support), and it circulates only as an online research chemical.
Evidence
Preliminary
Human evidence consists of short studies measuring growth hormone release after single doses; there are no clinical outcome trials.
In sport
WADAProhibited (WADA)
GHRP-6 is a six-amino-acid synthetic peptide from the early 1980s that triggers growth hormone release. Research on it and related compounds led to the discovery of the ghrelin receptor, but it was never developed into a medicine and is sold online as a research chemical.
Structure
6 residuesPoint at a bead, or focus the chain and use the arrow keys, to name it. Pick a chemistry to highlight it.
D-form (mirror image), shown in lower case
Sequence as text
H-H-D-Trp-A-W-D-Phe-K-NH2
What it is used for
- Stimulating growth hormone release in physiology research (studied)
- Muscle gain, appetite stimulation, fat loss or injury recovery (claimed, unproven)
How it works
GHRP-6 activates the growth hormone secretagogue receptor, the receptor for the stomach hormone ghrelin, on pituitary and hypothalamic cells. This releases growth hormone through a pathway separate from GHRH, which is why the two act synergistically. Unlike more selective agents such as ipamorelin, it also raises prolactin and cortisol at higher doses, and FDA notes it can reduce insulin sensitivity and raise blood glucose.
How strong the evidence is
Preliminary
Bowers and colleagues (1984) showed the hexapeptide released growth hormone in rats, monkeys and other species without releasing LH, FSH, TSH or prolactin in pituitary tissue. In 18 healthy men, single intravenous doses raised growth hormone in a dose-dependent way and acted synergistically with GHRH, while prolactin and cortisol roughly doubled only at the highest dose (Bowers 1990). Work on these secretagogues led to cloning of their receptor (Howard 1996), whose natural ligand, ghrelin, was identified in 1999 (Kojima). No controlled trials test GHRP-6 for any clinical outcome.
Risks and side effects
- Raises cortisol and prolactin and may reduce insulin sensitivity, raising blood glucose
- Immunogenicity and impurity risks flagged by FDA
- No long-term human safety data
- Research-chemical products are unregulated and of uncertain identity and purity
- Prohibited in sport at all times (WADA S2)
Regulatory status
Status by country
| Jurisdiction | Status | Source |
|---|---|---|
| USUnited States | No authorised medicine | Source 6 |
| EUEuropean Union | No authorised medicine | Source 9 |
| UKUnited Kingdom | No authorised medicine | Source 10 |
| AUAustralia | No authorised medicine | Source 11 |
| CACanada | No authorised medicine | Source 12 |
Sources
- 01GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) (CID 9919153)(opens the source in a new tab)
- 02On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone(opens the source in a new tab)
- 03Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone(opens the source in a new tab)
- 04A receptor in pituitary and hypothalamus that functions in growth hormone release(opens the source in a new tab)
- 05Ghrelin is a growth-hormone-releasing acylated peptide from stomach(opens the source in a new tab)
- 06Safety Risks Associated with Certain Bulk Drug Substances Nominated for Use in Compounding (Category 2)(opens the source in a new tab)
- 07Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (categories, updated May 14, 2026)(opens the source in a new tab)
- 08World Anti-Doping Code International Standard: Prohibited List 2026(opens the source in a new tab)
- 09Find medicine: centrally authorised medicines(opens the source in a new tab)
- 10MHRA Products: active substances beginning with G(opens the source in a new tab)
- 11Australian Register of Therapeutic Goods (ARTG)(opens the source in a new tab)
- 12Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks(opens the source in a new tab)
Educational information, not medical advice. Talk to a licensed clinician before starting, stopping or changing any medicine.