GHRP-6 is a synthetic hexapeptide growth hormone secretagogue studied for its effects on GH release and appetite; the information below compiles reported examples for educational use only, not medical advice.
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GHRP-6 Guide: Available Now
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
Reported in research contexts for growth hormone release, appetite stimulation, and body-composition studies
Plasma half-life
Measured in the one published human study: distribution 7.6 ± 1.9 min, elimination 2.5 ± 1.1 h (nine healthy men, intravenous)
Regulatory status
No FDA-approved product; Category 2 (significant safety risks) on the FDA's 503B list for outsourcing facilities, Category 3 on its 503A list for pharmacies; prohibited by WADA at all times under S2.2.4
Educational reference. This page does not publish dose ranges or reconstitution arithmetic.
What it is / mechanism
GHRP-6 is a synthetic hexapeptide that acts as a growth hormone secretagogue by binding the growth hormone secretagogue receptor (GHS-R1a), the same receptor targeted by the endogenous hormone ghrelin. Through this receptor it is reported to stimulate the pituitary to release growth hormone (GH) in pulses and to promote GH release with a mechanism distinct from GHRH analogues. Because it activates the ghrelin pathway, GHRP-6 is also reported to strongly stimulate appetite via neuropeptide Y (NPY) and agouti-related peptide (AgRP) neurons in the arcuate nucleus. As an early-generation GHRP, it is reported in research to also raise cortisol and prolactin to some degree, unlike more selective later secretagogues. Two naming details matter when checking any of this against a registry. GHRP-6 is an amide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, and the free-acid form is a different molecule; and PubChem carries the same hexapeptide under two records — CID 4345065, titled Ghrp-6 and holding no CAS number, and CID 9919153, titled Growth hormone releasing hexapeptide and holding CAS 87616-84-0 — both C46H56N12O6, 873.0 g/mol. CID 4345065 also lists GHRP-2 Acetate among its synonyms, which is wrong: GHRP-2 is pralmorelin, CID 6918245, C45H55N9O6, 818.0 g/mol, a separate compound this library covers separately. These are described mechanisms and registry facts, not statements of clinical benefit.
Researched effects
In research and community reports, GHRP-6 is associated with increased pulsatile growth hormone release, pronounced appetite stimulation, and interest in recovery and body-composition contexts; it is often studied alongside GHRH analogues for a synergistic GH pulse. These are research findings and community-reported observations, not guaranteed outcomes, and GHRP-6 is not approved to treat, cure, or prevent any condition.
Evidence & regulatory status
Best-documented human use is diagnostic, not therapeutic. The combined GHRH + GHRP-6 test is an established alternative to the insulin tolerance test for assessing growth hormone deficiency. In a reference-value study of 296 adults from the general population, 49 of whom took both tests (Eskes et al., Neth J Med 2009;67(4):127-33, PMID 19581656), the GH response was significantly higher in the GHRH/GHRP-6 test than in the insulin tolerance test, showed no sex difference, and was influenced by body mass index rather than by age. The test is used as a research and clinical measuring instrument; that is a different thing from GHRP-6 being a treatment.
Human pharmacokinetics rest on very little. A PubMed search for GHRP-6 and pharmacokinetics returns 36 records, and on review only one of them is a dedicated human pharmacokinetic study of the compound. Cabrales et al. (Eur J Pharm Sci 2013;48(1-2):40-6, PMID 23099431) gave nine healthy men a single intravenous bolus at three dose levels and measured plasma concentrations by validated LC-MS. Disposition fitted a two-compartment model (R-squared above 0.99); averaged across the three levels the distribution half-life was 7.6 ± 1.9 minutes and the elimination half-life 2.5 ± 1.1 hours. The authors also report unexplained concentration spikes during the elimination phase in four of the nine men.
The cortisol and prolactin effect is a class finding, and it is not uniform across species. A review of growth hormone secretagogues (Arvat et al., Endocrine 2001;14(1):35-43, PMID 11322500) states that the endocrine effects of this class are not fully specific for GH and include prolactin-, ACTH- and cortisol-releasing effects. The counter-observation is worth stating: in healthy Beagle dogs, GHRP-6 raised GH but produced no significant elevation of ACTH, cortisol, TSH, LH or prolactin (Bhatti et al., Vet J 2006;172(3):515-25, PMID 15951209).
Regulatory, United States — two lists, two placements. FDA keeps separate lists of bulk drug substances for outsourcing facilities under section 503B and for pharmacies under section 503A. On the 503B list (updated 21 March 2025), GHRP-6 is in Category 2, substances that raise significant safety risks. The reason FDA gives is specific: compounded drugs containing GHRP-6 may pose a risk for immunogenicity for certain routes of administration, because of the potential for aggregation and for peptide-related impurities. Ibutamoren mesylate, ipamorelin acetate and GHRP-2 (for its injectable and nasal routes only) sit in the same 503B category. On the 503A list (updated 14 May 2026), GHRP-6 is in Category 3 — nominated without adequate support — not Category 2.
Regulatory, sport: the World Anti-Doping Agency prohibits GHRP-6 at all times, in and out of competition, under section S2.2.4 (growth hormone releasing factors), where it is named explicitly alongside GHRP-1 through GHRP-5 and the secretagogue mimetics.
Registered trials of GHRP-6 do exist, but not on ClinicalTrials.gov and not of GHRP-6 alone. This page previously said that no registered trial exists; that was wrong, and it is withdrawn. ClinicalTrials.gov does return 0 studies for GHRP-6 (the control search growth hormone secretagogue returned 1,241 on 25 September 2026, so the query works). The trials sit in the Cuban Public Registry of Clinical Trials: a Phase I/II trial in 36 patients with acute ischaemic stroke, run July 2017 to January 2018 and registered as RPCEC00000214 (Front Neurol 2024, PMID 38638315), and its Phase III successor, COURAGE-2, which randomised 188 patients and missed its primary endpoint — no difference in disability, daily-living scores or survival at six months across all patients (J Clin Neurosci 2026, PMID 42462342). A better result in a subgroup of 27 patients with severe stroke is offered by the authors as a reason for a further trial, not as a finding. Both trials gave GHRP-6 intravenously together with epidermal growth factor, so neither measures GHRP-6 on its own, and both were run by the Havana centre that develops the combination. Outside that programme, PubMed indexes 786 records mentioning GHRP-6, 55 typed as clinical trials, most of them small physiological and diagnostic studies from the 1990s and 2000s.
No US drug label exists. An openFDA drug-label search for GHRP-6 returns no matches; the same query for semaglutide returns 5, so the absence is real rather than a failed query.
Research-use: sold and handled as a research chemical only; not intended for human or veterinary therapeutic use, and not approved to treat, cure or prevent any condition.
Research timeline
Dated milestones taken from the primary records: the molecule's discovery, its first registered human study, the trials that shaped the evidence and the regulatory decisions. Each entry links to the record it comes from.
Cyril Bowers and colleagues describe a new synthetic hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, that released growth hormone in rats, monkeys, lambs and calves without releasing LH, FSH, TSH or prolactin; it becomes known as GHRP-6. PMID 6714155
In 18 healthy men the hexapeptide raises growth hormone in proportion to the amount given and acts synergistically with growth-hormone-releasing hormone; no adverse clinical effects or laboratory abnormalities were seen with the peptide. PMID 2108187
A placebo-controlled overnight study in healthy men finds that GHRP-6 raised not only growth hormone but also ACTH and cortisol, unlike growth-hormone-releasing hormone. PMID 7617137
A multicentre study in The Lancet of 125 adults with pituitary disease and 125 healthy controls proposes the combined GHRH plus GHRP-6 injection as a convenient, safe and reliable test for adult growth hormone deficiency. PMID 11030292
FDA places GHRP-6 in Category 2 of its outsourcing-facility (503B) list, substances that raise significant safety risks, citing immunogenicity and safety concerns that include effects on cortisol and higher blood glucose through reduced insulin sensitivity. FDA · compounding safety risks, Apr 22, 2026
COURAGE-2, an open-label randomised Phase 3 trial, finds no difference in disability, daily-living scores or survival when GHRP-6 combined with epidermal growth factor was added to standard stroke care in 188 patients; benefit was claimed only in a small severe-stroke subgroup. PMID 42462342
Records checked Oct 4, 2026
Claims at a glance
The claims most often made about this compound, each with the strongest kind of evidence we found for it. The grade says what was studied, not whether the claim is true; the line beside it says what that study showed.
Strongly increases hungerAnimal studies only. Food intake rose in animals such as goldfish; no human study has given people GHRP-6 and measured how much they ate. PMID 22349352
Builds muscle and supports recoveryNo study found. A PubMed search for GHRP-6 with muscle, body-composition, lean-mass or fat-mass terms in humans returned 11 records, all reviews, mechanism or animal work. PubMed search, Oct 6, 2026
Releases growth hormone, more so with GHRHHuman, non-randomised. In 18 healthy men, growth hormone rose with each step up, and together with GHRH the release was more than the two added up. PMID 2108187
Raises growth hormone without raising cortisolHuman, non-randomised. Given overnight to healthy men against placebo, it raised ACTH and cortisol as well as growth hormone, the opposite of GHRH. PMID 7617137
Deepens sleepHuman, non-randomised. In the one sleep-lab study, in healthy men, light (stage 2) sleep increased and deep slow-wave sleep did not change. PMID 7617137
Improves recovery after strokeHuman, randomised trial. An open-label randomised phase 3 trial in 188 people, with GHRP-6 always given together with EGF, missed its primary endpoint. PMID 42462342
The reasoning behind each grade, study by study, is in this guide's Benefit & Outcome Review.
Grades checked Oct 6, 2026
A printable reference sheet with the compound's key facts, storage guidance and a vial record comes with All-Access Lifetime.
Half-life & pharmacokinetics
The figure widely repeated for GHRP-6 — a plasma half-life of about 15 to 20 minutes — is not what the published human measurement says, and this page previously repeated it. In the one human pharmacokinetic study we could find (Cabrales et al., Eur J Pharm Sci 2013;48(1-2):40-6, PMID 23099431), nine healthy men received a single intravenous bolus and plasma GHRP-6 was measured by a validated LC-MS method. Disposition fitted a two-compartment model, and averaged over three dose levels the distribution half-life was 7.6 ± 1.9 minutes and the elimination half-life 2.5 ± 1.1 hours. So the fast phase is shorter than the repeated figure and the slow phase is not a fringe claim but the measured elimination half-life. Three conditions travel with those numbers and are usually dropped: the route was intravenous, not subcutaneous; the sample was nine men, with no women studied; and the authors report unexplained concentration spikes during the elimination phase in four of the nine. Treat them as the best available human measurement rather than as a settled constant.
Reported side effects & toxicology
Human safety data are limited, and GHRP-6 is not an approved drug. As an early-generation GHRP it is reported to cause strong appetite and hunger, and to raise cortisol and prolactin more than the selective secretagogues do. That second point is a class finding rather than a GHRP-6-specific measurement (Arvat et al., Endocrine 2001, PMID 11322500), and it does not hold in every species: in healthy dogs GHRP-6 raised GH without significantly moving ACTH, cortisol, TSH, LH or prolactin (Bhatti et al., Vet J 2006, PMID 15951209). Other reported effects include water retention, tingling or numbness in the hands, temporary drops in blood sugar, flushing, head-rush sensations, and injection-site reactions. These are reported observations, not a complete safety profile, and long-term human safety has not been established.
Storage & handling
Lyophilized (powder): reported stable refrigerated at 2-8 C, and can be kept frozen for longer-term storage; keep away from light and moisture.
Reconstituted (liquid): reported to be kept refrigerated at 2-8 C and used within about 2-4 weeks; do not freeze after reconstitution and avoid shaking.
References
Sources opened for this page: Cabrales et al., Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers, Eur J Pharm Sci 2013;48(1-2):40-6 (PMID 23099431); Eskes et al., Establishment of reference values for endocrine tests, Part VII: growth hormone deficiency, Neth J Med 2009;67(4):127-33 (PMID 19581656); Arvat et al., Endocrine 2001;14(1):35-43 (PMID 11322500); Bhatti et al., Vet J 2006;172(3):515-25 (PMID 15951209); Esposito et al., J Pept Sci 2015;21(1):1-9 (PMID 25469748); Hernández-Bernal et al., Front Neurol 2024 (PMID 38638315, Cuban Public Registry RPCEC00000214); the COURAGE-2 Phase III report, J Clin Neurosci 2026 (PMID 42462342); PubChem CID 4345065 and CID 9919153; the FDA list of bulk drug substances for use in compounding that may present significant safety risks (Category 2); and the WADA Prohibited List, section S2.2.4. Absence statements on this page name the search that was run and the control search that returned results. Educational research use only, not medical advice.
Evidence File
The GHRP-6 Evidence File: 804 Papers, a Third of Them About a Different Molecule, and One Treatment Trial That Missed
GHRP-6 looks like one of the best-studied compounds in this library: PubMed indexes 804 records once every name is searched, 55 of them typed as clinical trials. Read them and the picture changes. 284 of the 804 also concern [D-Lys3]-GHRP-6, a different molecule that blocks the receptor GHRP-6 activates, and since 2020 more of the new papers involve that blocker than do not. Of the 55 trial-typed records, six are animal studies and eleven gave people a different substance. The remaining 38 are almost all hormone-response tests lasting hours. Exactly one is a treatment trial with a clinical outcome — a 2026 Phase III stroke trial run in Cuba, which missed its primary endpoint. This file takes the corpus apart and says what each piece can support.
804 records in the corpus; 284 of them also concern a receptor-blocking analogue
55 trial-typed records; 38 in which people were actually given GHRP-6
1 treatment trial with a clinical outcome, and it missed its primary endpoint
How large this literature is, and how much of it is about something else
When it was studied, and in whom
The 55 trial-typed records, sorted by what was actually given to whom
The Cuban stroke programme: the only place GHRP-6 was tested as a treatment
What has never been measured
5 more sections in the Evidence File for GHRP-6
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for GHRP-6 for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Sourcing File
The GHRP-6 Sourcing File: Three Molecules Within 60 Daltons, Two PubChem Records, and the Impurities the FDA Named
GHRP-6 is a defined synthetic hexapeptide, which makes it easier to verify than an extract — but only if you know which neighbours to rule out. Within 60 daltons of it sit hexarelin, which differs by one methyl group and is sold as a separate product, and [D-Lys3]-GHRP-6, a receptor blocker that does the opposite. PubChem keeps GHRP-6 under two records, one of which lists GHRP-2 as a synonym by mistake. And two of the six amino acids are the mirror-image D form, so an impurity with one of them flipped has exactly the same mass and passes a mass check. The FDA's stated reason for listing GHRP-6 among substances with significant safety risks is specific: aggregation and peptide-related impurities. This file turns all of that into questions to put to a certificate of analysis.
873.0 g/mol — and two neighbours at 887.0 and 930.1 that a certificate must rule out
2 PubChem records for one molecule, one listing GHRP-2 as a synonym
2 of 6 residues in the D form, so a mirror-image impurity has the same mass
1 FDA reason, stated in writing: aggregation and peptide-related impurities
What GHRP-6 is, and the two registry records that describe it
The three near neighbours a mass spectrum must rule out
The impurities a mass check cannot see
What the FDA said, and why it points at the certificate
What to ask a supplier, in the order to read it
5 more sections in the Sourcing File for GHRP-6
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for GHRP-6 for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Benefit & Outcome Review
The GHRP-6 Benefit & Outcome Review: What It Does in Hours Is Well Measured; What It Is Bought For Has Never Been Tested
GHRP-6 is bought for appetite, for muscle and recovery, and for a stronger growth-hormone pulse. The human research answers the third question thoroughly and the first two not at all. Across 38 studies that gave people GHRP-6, it reliably raises growth hormone within minutes, works with GHRH more than additively, and also raises cortisol, ACTH and prolactin. No human study measured appetite or food intake after it. No human study measured muscle, fat or strength. The only treatment trial with a clinical outcome — a 188-patient stroke trial giving GHRP-6 with epidermal growth factor — missed its primary endpoint in 2026. This review takes each claimed benefit in turn and separates what was measured from what is inferred.
38 studies in which people were given GHRP-6; 37 measured hormones, not outcomes
0 human studies of appetite, muscle or body composition after GHRP-6
188 stroke patients in the only outcome trial — no difference overall at six months
71% sensitivity, 78% specificity — its accuracy as an adrenal test against the reference
The growth hormone pulse: the one claim the evidence fully supports
Cortisol, ACTH and prolactin: an effect that became a diagnostic test
Its real medical use: measuring the pituitary, not treating anything
Appetite, muscle and recovery: the reasons it is bought, measured nowhere in people
The one outcome trial, and the honest negative it delivered
What no benefit claim here can rest on
6 more sections in the Benefit & Outcome Review for GHRP-6
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for GHRP-6 for $14 — or every compound in the library, plus the printable reference sheets, for $99.
Quick answers about guide scope, access, and educational use context.
What is GHRP-6 and how does it work?
GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide growth hormone secretagogue. It is reported to bind the ghrelin receptor (GHS-R1a) and stimulate pulsatile growth hormone release, while also strongly stimulating appetite. This is described mechanism from research, not a claim of clinical benefit.
How is GHRP-6 different from ipamorelin?
Both are ghrelin-receptor agonists, but GHRP-6 is an early-generation GHRP reported to raise cortisol, prolactin, and appetite alongside GH, whereas ipamorelin is reported to be more selective with fewer of those effects. Some users pick GHRP-6 specifically for the appetite stimulation. These are reported differences, not recommendations.
Is there an established GHRP-6 dose?
No. The published human work gave GHRP-6 intravenously — as a single bolus in a pharmacokinetic study and as part of a diagnostic pituitary test — and the amounts quoted in community sources come from no dose-finding study, so this page does not reproduce them. Education only, not a personal dose or medical advice.
Is GHRP-6 legal or FDA-approved?
There is no FDA-approved GHRP-6 product and no US drug label for it — an openFDA label search returns no matches, while the same search for semaglutide returns 5, so the absence is real. GHRP-6 is also named on the FDA's Category 2 list of bulk drug substances nominated for compounding that may present significant safety risks; the stated concern is immunogenicity for certain routes of administration, arising from the potential for aggregation and peptide-related impurities. Always follow the laws and regulations that apply to you.
Has GHRP-6 ever been used in mainstream medicine?
Yes, but as a measuring instrument rather than as a treatment. The combined GHRH + GHRP-6 test is an established alternative to the insulin tolerance test for assessing growth hormone deficiency. In a reference-value study of 296 adults, 49 of whom took both tests, the GH response was significantly higher in the GHRH/GHRP-6 test than in the insulin tolerance test, was influenced by body mass index rather than age, and showed no difference between men and women (Eskes et al., Neth J Med 2009, PMID 19581656). That is the best-documented human use of the compound, and it is diagnostic.
Are there registered clinical trials of GHRP-6?
Yes, two, though not where most people look and not of GHRP-6 alone — and this page previously said there were none, which was wrong. ClinicalTrials.gov returns 0 studies for GHRP-6. The Cuban Public Registry of Clinical Trials holds a Phase I/II stroke trial in 36 patients (RPCEC00000214; Front Neurol 2024, PMID 38638315), and a Phase III successor, COURAGE-2, randomised 188 patients with acute ischaemic stroke and missed its primary endpoint: no difference in disability, daily-living scores or survival at six months (J Clin Neurosci 2026, PMID 42462342). Both gave GHRP-6 intravenously together with epidermal growth factor, so neither tests GHRP-6 by itself. The rest of the human literature — 55 PubMed records typed as clinical trials — is mostly small physiological studies from the 1990s and 2000s, which predate trial registration.
Is GHRP-6 detectable in anti-doping testing?
Yes. It is prohibited at all times under section S2.2.4 of the WADA Prohibited List, named explicitly alongside GHRP-1 to GHRP-5, and anti-doping laboratories have studied its metabolism specifically to improve detection of short-lived peptides (Esposito et al., J Pept Sci 2015, PMID 25469748). A short half-life is not the same as being undetectable, because testing can target metabolites rather than the parent peptide.
Compliance and trust notes
Educational content only; no personalized health or outcome claims.
No personalized use recommendation outputs.
Use this material for general learning and research-context literacy.
A certificate of analysis (COA) is a laboratory’s report on one sample of one batch. The single most useful thing to know about it is that purity and identity are two separate results that fail in different ways. A high purity figure says the sample was mostly one substance; it does not say that substance was GHRP-6. Identity — normally a mass-spectrometry result matching the expected molecular weight — is what establishes what the material actually is, and a certificate reporting purity alone has not answered that question.
Two further limits are worth holding onto. Mass per vial is its own test: a vial can be 99% pure and still contain less material than the label claims. And sterility, endotoxin, heavy metals and residual solvent screening are separately commissioned tests, usually priced individually — so a “third-party tested” badge asserts none of them unless the certificate names them. Check that the batch or lot number on the document matches the vial in front of you; an unmatched certificate describes someone else’s material.
Medibact does not test, endorse or resell peptides, and publishes no rating of any laboratory. How to read a peptide certificate of analysis walks through the document section by section, and what each COA field establishes covers the field-by-field detail and the laboratories that publish their methods.
You’ll need bacteriostatic water
The diluent for reconstituting GHRP-6
Reconstitution is volume arithmetic — it assumes a lyophilized vial is dissolved in bacteriostatic water, which is sterile water preserved with 0.9% benzyl alcohol. The preservative is what allows a vial to be entered more than once; plain sterile water carries none and is single-entry by design. Medibact supplies USP-grade Bacteriostatic Water for Injection in a 30 mL multi-dose vial, made in the United States and shipped from the United States, for research use only. One 30 mL vial covers 30 reconstitutions at 1 mL each, 15 at 2 mL, or 10 at 3 mL — division only, not a dosing recommendation.
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
