GHRP-1 is a synthetic heptapeptide that prompts the pituitary to release growth hormone (GH). It belongs to the growth hormone secretagogue (GHS) family, the same broad group as GHRP-2, GHRP-6, hexarelin and ipamorelin. Its CAS number is 141925-59-9. You may also see it written as GHRP 1 or under its UNII code 39EVI31P0W.
The defining feature of this whole class is that it raises GH through a different door than growth hormone–releasing hormone (GHRH). GHRPs share no structural similarity with GHRH and act on their own receptor, which when it was cloned showed no sequence homology with other known G-protein-coupled receptors. That receptor is now identified as the ghrelin receptor (GHS-R1a). In short pharmacology terms, GHRP-1 is a ghrelin-receptor agonist that drives GH secretion.
What the research actually shows
GHRP-1 was characterized in the 1990s, when several GHRPs were synthesized for human study alongside the more thoroughly investigated GHRP-2 and GHRP-6.
The clearest experimental data come from cell work. In a 1994 study on ovine (sheep) pituitary cells in culture, GHRP-1 stimulated GH release in a dose-dependent way, with a half-maximal effective dose around 10⁻⁷ M, similar to GHRP-6. Blocking calcium channels with cadmium fully and reversibly shut down the releasing effect, which points to calcium-dependent signaling. The same study noted that a GHRH antagonist did not block GHRP-1's action, reinforcing that it works through a separate pathway (Bowers-era cell study, PubMed).
Reviews from the period describe GHRPs, GHRP-1 included, as active across several routes: intravenous, subcutaneous, intranasal and even oral, with reproducible dose-related GH responses. Effects vary with age, rising from birth toward puberty and tapering in later decades (European Journal of Endocrinology review, PubMed). For the broader GHS picture and how these molecules signal through an IP₃/calcium pathway distinct from GHRH, see the overview at ScienceDirect Topics.
Where GHRP-1 differs from its siblings is depth of evidence. GHRP-2 (pralmorelin) and GHRP-6 were studied far more extensively and remain reference compounds in the literature. GHRP-1 appears mostly in early comparative work and review articles rather than in a substantial body of its own human trials. There is no approved GHRP-1 drug product. DrugBank lists it as experimental, not an approved medicine.
Regulatory and anti-doping status
GHRP-1 is not an approved drug in the US, EU or elsewhere that public records show. It is sold only as a research chemical, labeled research use only and not for human consumption.
For athletes, the status is unambiguous. Growth hormone secretagogues and GH-releasing peptides are banned at all times under section S2 of the WADA Prohibited List. Secondary references summarizing S2 name the GHRP series (GHRP-1 through GHRP-6) explicitly as prohibited (drugs.com WADA S2 summary).
The buyer's quality angle
Because GHRP-1 is a niche research peptide rather than a pharmaceutical, there is no regulated supply chain behind it. Whatever ships in a vial is only as good as the lab that made it and the testing that backs it. Two things matter most:
- Identity and purity. A certificate of analysis (COA) from third-party testing, ideally mass spectrometry for identity plus HPLC for purity, tied to the specific batch you are buying.
- Independent verification. Vendor self-reported numbers are not the same as an outside lab confirming the peptide is what the label claims, at the stated purity.
This site aggregates public COAs and the assessments of independent raters so you can compare what vendors actually document rather than what they assert. None of that is an endorsement to use the compound.
Nothing here is medical, dosing or efficacy advice. GHRP-1 is not approved for human use, and the published human research on this specific peptide is thin compared with the better-studied members of its family.