Not approved; on an FDA safety listGHRP-6 has no FDA approval.[1] The FDA places it in 503B Category 2 and writes that the available data "reveal safety concerns including potential effect on cortisol and increase in blood glucose due to decreases in insulin sensitivity".[3] This page does arithmetic and reports the record; it does not suggest amounts.
What is GHRP 6?
GHRP 6 is a synthetic six-amino-acid peptide that makes the pituitary release growth hormone by acting on the ghrelin receptor, the same receptor ipamorelin uses.[20]
- Sequence
- His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, 6 residues, two of them D-amino acids, with an amide end[20]
- Formula and weight
- C46H56N12O6, 873.0 g/mol; CAS 87616-84-0[20]
- Our engine
- C46H56N12O6, 873.03 g/mol. D-amino acids are mirror images, so they weigh the same as the L forms a sequence calculator assumes
- Other names
- Growth hormone releasing hexapeptide, SK&F-110679[20]
A caution for anyone checking PubChem: a second record for "Ghrp-6" has no stereochemistry and wrongly lists GHRP-2 acetate as a synonym. CID 9919153 is the correct one.[20] For how the amide end changes the weight, see the molecular weight calculator.
Is GHRP 6 legal or FDA-approved?
No GHRP-6 product is approved, and the FDA has placed it on two compounding lists: 503B Category 2 for outsourcing facilities and 503A Category 3 for pharmacies.[1][5][4]
| List | Category | What it means |
|---|---|---|
| 503B outsourcing facilities[5] | Category 2, since Sept 29, 2023 | Substances that raise significant safety concerns; the FDA cites immune-reaction risk plus cortisol and blood-sugar effects |
| 503A pharmacies[4] | Category 3, on every list from Apr 2019 to May 2026 | "Nominated without adequate support", so the FDA has not been given enough information to evaluate it |
| Advisory committee[4] | Never reviewed | Unlike BPC-157 or kisspeptin, GHRP-6 has not been taken to the compounding advisory committee |
| HHS policy, Oct 2026[6] | Not included | The enforcement-discretion policy lists six peptides; GHRP-6 is not one |
- Warning letters. Two 2019 letters to pharmacies said plainly that "GHRP-2 and GHRP-6 were not nominated with adequate support for FDA to evaluate the substances".[7][8] A 2020 letter noted the firm had removed both from its formulary.[9]
- Import alert. FDA Import Alert 66-41 has carried a GHRP-6 entry for a Beijing supplier since August 2012, allowing detention without physical examination.[10]
- Orphan designation. None found.[2]
The practical reading: GHRP-6 is an unapproved drug substance, and a pharmacy that compounds with it is outside the exemptions. See are peptides legal? and are peptides safe?
What the GHRP 6 studies actually tested
All published GHRP-6 research used it as a short-term growth hormone stimulus in a clinic; no trial has tested it as a treatment for any condition.[11]
| Study | Design and people | Route | Reported |
|---|---|---|---|
| Ilson 1989[12] | 17 healthy men plus 8 on saline | Intravenous infusion | Growth hormone rose in a dose-dependent way; LH, FSH, TSH and ACTH unchanged. Described as well tolerated |
| Bowers 1990[13] | 18 healthy men, alone or with GHRH | Intravenous bolus | Growth hormone rose and acted synergistically with GHRH. Prolactin and cortisol roughly doubled at the highest amount tested |
| Bellone 1995[14] | 13 children of normal short stature | Oral, as a diagnostic test | Growth hormone peak similar to an intravenous GHRH test |
| Cabrales 2013[15] | Pharmacokinetics, 9 healthy men | Single intravenous bolus | Distribution half-life 7.6 minutes, elimination half-life 2.5 hours; unexplained concentration spikes in 4 of the 9 |
- Cortisol and prolactin. The doubling Bowers reported is the basis of the FDA's cortisol concern; it is why GHRP-6 is not a clean growth hormone stimulus.[13][3]
- Insulin sensitivity. The FDA cites an increase in blood glucose from reduced insulin sensitivity among the safety concerns.[3]
- No registered trials. ClinicalTrials.gov lists no study with GHRP-6 as an intervention.[11]
Compared with the other growth hormone peptides on this site, that is a thin record: see HGH peptides compared, where tesamorelin has two phase 3 trials and an FDA label.
GHRP 2 vs GHRP 6, and ipamorelin vs GHRP 6
All three act on the ghrelin receptor, but the FDA treats them differently and only ipamorelin has been through an advisory committee: GHRP-2 is split by route of administration, GHRP-6 is in 503B Category 2 outright, and ipamorelin was voted down in 2024.[5][17]
| GHRP-6 | GHRP-2 (pralmorelin) | Ipamorelin | |
|---|---|---|---|
| Length | 6 amino acids | 6 amino acids | 5 amino acids, 711.85 g/mol[21] |
| 503B category | Category 2[5] | Category 2 for injectable and nasal routes; Category 1 for other routes[5] | Category 2[5] |
| Advisory committee | Never reviewed | Never reviewed | Voted against, October 2024[17] |
| Selectivity | Raises cortisol and prolactin as well as GH[13] | Not assessed here; we found no primary source on its hormone selectivity | Described by the FDA as more selective for GH[16] |
| Human evidence | Single-dose GH studies only[12][13] | Not reviewed on this page | Intravenous studies, including a phase 2 after bowel surgery[16] |
| WADA 2026 | S2.2.4, named[18] | S2.2.4, named as pralmorelin[18] | S2.2.4, named[18] |
The one meaningful difference between GHRP-6 and ipamorelin is selectivity: the FDA's own review describes ipamorelin as the more selective growth hormone secretagogue, while GHRP-6 roughly doubled prolactin and cortisol in healthy men.[16][13] Neither has a treatment trial behind it. The ipamorelin page has that record in full.
GHRP 6 and sport
GHRP-6 is prohibited at all times. WADA's 2026 list names it directly in S2.2.4: "GH-releasing peptides (GHRPs) [e.g. alexamorelin, examorelin (hexarelin), GHRP-1, GHRP-2 (pralmorelin), GHRP-3, GHRP-4, GHRP-5 and GHRP-6]".[18]
- Classification. S2 substances are non-Specified and banned both in and out of competition.[18]
- 2027. USADA's advisory keeps GHRPs under S2 on the 2027 list.[19]
- Related. Hexarelin is named in the same entry; it is GHRP-6 with one methyl group added.
More on are peptides banned in sports?
GHRP 6 weight math
At 873.0 g/mol, 1 mg of GHRP-6 is 1,145 nmol. The chart shows concentration for common vial sizes once liquid is added.
| Vial + liquid | mg/mL | mcg per unit | nmol per unit | Units per 100 mcg |
|---|---|---|---|---|
| 2 mg + 1 mL | 2 | 20 | 22.91 | 5 |
| 2 mg + 2 mL | 1 | 10 | 11.45 | 10 |
| 5 mg + 1 mL | 5 | 50 | 57.27 | 2 |
| 5 mg + 2 mL | 2.5 | 25 | 28.64 | 4 |
| 10 mg + 1 mL | 10 | 100 | 114.55 | 1 |
| 10 mg + 2 mL | 5 | 50 | 57.27 | 2 |
Note the acetate question: suppliers often ship peptide acetate salts, so the powder in a vial can weigh more than the peptide it contains. The general rules are on how to reconstitute peptides.
Other peptide pages
The peptides most often looked up alongside this one. Each page gives that peptide's FDA status, compounding status and published human evidence, with sources; the status table has all 23 in one place.
- TesamorelinFDA-approved Egrifta SV and Egrifta WR. Labeled doses, diluents and volumes.
- CJC-1295 / ipamorelinNot approved Two growth-hormone secretagogues, often sold together. Both rejected for compounding in 2024.
- SermorelinDiscontinued Once sold as Geref. Discontinued in 2008, not for safety reasons.
- AOD-9604Not approved Growth hormone fragment. Obesity trials failed; committee voted 0–12.
- HexarelinNot approved GHRP-6 plus one methyl group. Studied in the 1990s, never approved.
- BPC-157Not approved 15-amino-acid peptide. Human data: a few tiny, uncontrolled studies.
Frequently asked questions
Is GHRP 6 FDA-approved?
What does GHRP 6 do?
It acts on the ghrelin receptor to make the pituitary release growth hormone. In healthy men it also roughly doubled prolactin and cortisol at the highest amount tested.[13]
What is the difference between GHRP-6 and GHRP-2?
Sources
- openFDA Drugs@FDA searches for thymalfasin, thymosin, kisspeptin, emideltide, hexarelin, examorelin, GHRP, cathelicidin and Zadaxin (no match)
- Search orphan drug designations and approvals (thymalfasin: 4 designations; kisspeptin, hexarelin, emideltide, cathelicidin: none)
- Certain bulk drug substances for use in compounding that may present significant safety risks
- Bulk drug substances nominated for use in compounding under section 503A (category lists)
- Bulk drug substances nominated for use in compounding under section 503B (category lists)
- Enforcement discretion policy regarding 503A compounding using certain peptide bulk drug substances (91 FR 68526)
- Warning letter: United Pharmacy
- Warning letter: ImprimisRx CA, Inc.
- Warning letter: Tailor Made Compounding LLC
- Import Alert 66-41: unapproved new drugs promoted in the U.S.
- ClinicalTrials.gov searches: hexarelin, GHRP-6, emideltide and DSIP as interventions (0 studies)
- Ilson BE et al. Effect of a new synthetic hexapeptide (GHRP-6) on GH secretion in normal men (J Clin Endocrinol Metab 1989;69:212–214)
- Bowers CY et al. GHRP-6 and GHRH: synergistic GH release in normal men (J Clin Endocrinol Metab 1990;70:975–982)
- Bellone J et al. Oral GHRP-6 in children with normal short stature (Eur J Endocrinol 1995;133:425–429)
- Cabrales A et al. Pharmacokinetics of GHRP-6 in healthy male volunteers (Eur J Pharm Sci 2013;48:40–46)
- FDA briefing document: ipamorelin-related bulk drug substances
- Pharmacy Compounding Advisory Committee, October 29, 2024: transcript (ipamorelin and kisspeptin-10)
- World Anti-Doping Code: Prohibited List 2026
- Athlete advisory: what's new on the 2027 WADA Prohibited List
- PubChem CID 9919153: growth hormone releasing hexapeptide (GHRP-6)
- PubChem CID 9831659: ipamorelin