GHRP-6

Definition

GHRP-6 is a synthetic hexapeptide that releases growth hormone through the ghrelin receptor. It is the older and more widely studied of the two growth hormone-releasing peptides this index tracks, and it was the compound that established the receptor pathway itself: the earliest human work showed that the peptide releases growth hormone independently of growth hormone-releasing hormone and acts synergistically with it.

Like its sibling, it is sold in the United States as research-use-only material. Its federal file is the same two-list arrangement, and the same two-list arrangement is what a single-source summary of its status gets wrong.

Evidence

Across five name variants PubMed returns 801 indexed records, of which 316 carry the Humans subject heading, 56 the clinical-trial publication type, and 25 the randomized-controlled-trial type ^[1]. The publication-type filter was proved live in the same run against a control term returning 8,906 records under the clinical-trial type and 6,115 under the randomized type; the invalid tag returned zero for that control term; and a deliberately invalid record identifier errored in the same run ^[1].

Fifty-six is not fifty-six trials of this compound, and the reading is the reason to say so. All 56 titles were retrieved and opened. The union draws in hexarelin, ghrelin itself, the non-peptide mimetics that were developed from the hexapeptide, and animal work in cattle, dogs and rats, because the phrase that identifies the compound also identifies its whole pharmacological neighborhood ^[1]. A count published without that reading would attribute a receptor family's literature to one molecule sold from it.

What is left, after reading, is a provocation and diagnostic literature. The characteristic study administers the peptide and measures growth hormone, adrenocorticotropic hormone or cortisol release, often in comparison with growth hormone-releasing hormone or the insulin tolerance test; a trial in growth hormone-deficient adults proposed the combination as a diagnostic alternative to that test ^[2]. A separate study measured its effect on sleep architecture alongside the hormonal response ^[3]. One pharmacokinetic study administered the peptide to nine healthy male volunteers ^[4].

The one indexed record that reports a therapeutic outcome is not a trial of GHRP-6 alone: a 2026 phase 3 open-label randomized trial in acute ischemic stroke tested epidermal growth factor combined with growth hormone releasing hexapeptide, and it was conducted outside the United States ^[5]. A combination product studied for a neurological indication abroad is not evidence for the uses the compound is sold for here, and the distance is worth naming rather than leaving to inference.

Lawful access

There is no lawful United States supply route. Drugs@FDA holds no approved product with GHRP-6 as an active ingredient; in the same session and the same query form, bremelanotide returned one application and liraglutide returned fourteen, and a deliberately invented ingredient name returned none ^[6].

The section 503A bulks list FDA published May 14, 2026 lists GHRP-6 in Category 3, the file for substances nominated without adequate support to evaluate, and in neither of the other two categories ^[7]. Category 3 is a statement about the nomination, not about the published literature and not about safety. A substance can hold eight hundred indexed records and a Category 3 file at the same time, and this one does.

Under the separate section 503B policy, GHRP-6 is in Category 2, added September 29, 2023. FDA states there that compounded drugs containing it may pose a risk for immunogenicity for certain routes of administration due to the potential for aggregation and peptide-related impurities, and that it has identified limited safety-related information, with the available data revealing concerns including a potential effect on cortisol and an increase in blood glucose from decreased insulin sensitivity ^[8]. That is the only place in the federal record where an agency safety view of this compound is stated, and it is stated about outsourcing facilities rather than about pharmacies.

The substance was not among the seven peptides the advisory committee reviewed in July 2026 ^[7]. What is sold is research-use-only material, on the same terms as everything else in that file.

Related molecules

GHRP-6 and GHRP-2 hold the same pair of positions and are the two GH secretagogues in Category 3; the class also holds an approved drug in tesamorelin, a lawfully compounded one in sermorelin, and two whose nominations were withdrawn. The nomination tracker files each of them by what became of its nomination, and the human trial record prints the count this page has just explained is not what it looks like.

Elsewhere in this index