A research-focused Hexarelin guide covering the dose the published human studies actually administered, the one 16-week trial every cycling recommendation traces back to, and what a certificate of analysis establishes — educational use only, not medical advice.
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Hexarelin 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.
Hexarelin at a glance
What it is
A synthetic six-amino-acid growth hormone-releasing peptide (GHRP) and ghrelin-receptor agonist, structurally related to GHRP-6
Researched for
Growth hormone secretion — largely as a diagnostic pituitary challenge agent — and, separately, CD36-mediated cardiovascular research
Dose used in human trials
1-2 mcg/kg intravenously as a single challenge (about 70-140 mcg for a 70 kg adult), or 10 mg orally; not the subcutaneous figure community sources cite
Plasma half-life
Reported at roughly 55-80 minutes — a figure that circulates widely but is not stated in the abstracts of the human trials most often cited for it
Regulatory status
Not FDA-approved; no registered clinical trial is currently listed on ClinicalTrials.gov; WADA-prohibited (S2) in sport; sold for laboratory research use only
Educational reference. This page does not publish dose ranges or reconstitution arithmetic.
What it is / mechanism
Hexarelin is a synthetic hexapeptide in the growth hormone secretagogue class, closely related to GHRP-6 but modified for greater metabolic stability. It acts at the growth hormone secretagogue receptor type 1a (GHS-R1a), the receptor for ghrelin, and is reported as one of the more potent GHRPs, producing GH pulses exceeding those of GHRP-6 and GHRP-2 at equivalent molar doses. Where it acts is the more interesting question, and the trial record answers it directly. In 15 children and 4 adults with growth hormone deficiency (Loche et al., JCEM 1995), hexarelin stimulated GH normally in idiopathic deficiency but the response was absent or blunted in patients whose pituitary was anatomically disconnected from the hypothalamus — evidence the authors described as strongly supporting a hypothalamus-mediated effect rather than a purely pituitary one. A separate study found hexarelin had no effect on TRH-induced TSH secretion (Arosio et al., J Endocrinol Invest 1998), which argues against a simple 'suppresses somatostatin everywhere' account. Hexarelin also interacts with the CD36 scavenger receptor in cardiac tissue, a research thread studied independently of GH release.
Researched effects
In healthy children and adults hexarelin reliably and reproducibly raises growth hormone, and the response is larger than GHRH at the doses compared: in 96 children, 2 mcg/kg intravenously produced a greater GH increase than 1 mcg/kg of GHRH, and the response grew during puberty (77.5 vs 39.4 mcg/L, prepubertal versus pubertal). It is not a selective secretagogue, and this is the point most commercial pages omit. Hexarelin is reported to raise cortisol, prolactin and ACTH more than milder GHRPs, and the paediatric work measured those responses explicitly — a slight prolactin rise in both prepubertal and early pubertal children, with cortisol responses varying by pubertal stage. Selectivity is precisely the property ipamorelin is valued for; hexarelin is the opposite end of that trade-off, and choosing it means accepting the cortisol and prolactin signal alongside the larger GH pulse.
Evidence & regulatory status
Evidence: a genuine human literature exists, but it is almost entirely acute and diagnostic. Studies from the 1990s and early 2000s administered hexarelin as a single intravenous challenge to characterise pituitary function — in healthy children, in growth-hormone-deficient patients, and across pubertal stages. Chronic administration was studied once in humans, in 12 people.
Regulatory: not FDA-approved for any indication, and a search of the FDA drug-label database returns no hexarelin label. It is explicitly named on the WADA Prohibited List (S2, peptide hormones and growth factors) and is prohibited in and out of competition.
Trial status: a search of ClinicalTrials.gov for hexarelin as an intervention returns no registered studies at all. For a compound with an active commercial market, an empty trial registry is itself information — nothing is currently being tested, anywhere, under a protocol.
Research use: sold and labelled strictly for laboratory research use, not for human, clinical or veterinary use. Research-grade labelling does not exempt the molecule from WADA jurisdiction.
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.
A study in 12 healthy young volunteers shows that hexarelin, a new synthetic hexapeptide, releases growth hormone when given into a vein, under the skin, into the nose or by mouth, with an intravenous response about twice that of growth-hormone-releasing hormone. PMID 8126144
A dose-response study in healthy men finds that hexarelin raises prolactin and cortisol as well as growth hormone, so it is not a selective growth-hormone releaser. PMID 8954038
After 16 weeks of twice-daily hexarelin in adults, the growth-hormone response to the peptide is partly blunted and recovers four weeks after stopping; body fat, lean mass and bone density had not changed significantly. PMID 9589671
In seven men with growth hormone deficiency and nine controls, intravenous hexarelin briefly raised the heart's ejection fraction in both groups although the patients released almost no growth hormone, pointing to a direct effect on heart muscle. PMID 10528131
A placebo-controlled sleep study in seven young volunteers finds that hexarelin reduced deep slow-wave sleep while raising growth hormone, ACTH, cortisol and prolactin overnight, unlike ghrelin and growth-hormone-releasing hormone, which promote slow-wave sleep. PMID 15177700
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.
Builds muscle and reduces body fatHuman, non-randomised. In the only adult study long enough to measure it, 16 weeks in healthy older people, fat mass, lean mass and bone density did not change. PMID 9589671
Raises IGF-1Human, non-randomised. IGF-1 did not change over 16 weeks in older adults; it rose in eight short children given a nasal form for up to eight months. PMID 8548949
Strengthens the heartHuman, non-randomised. Single intravenous doses briefly raised ejection fraction in healthy people and during bypass surgery, but not in dilated cardiomyopathy; no long-term heart study exists. PMID 11322491
Deepens sleepHuman, non-randomised. The one sleep-lab study, in seven young volunteers against placebo, found the opposite: deep (stage 4) sleep and delta activity decreased. PMID 15177700
Increases appetiteHuman, non-randomised. In fifteen healthy young men, rating scales showed what the authors called a small, acute rise in appetite. PMID 10404825
Raises cortisol and prolactinHuman, non-randomised. Single doses do raise both; over 16 weeks of repeated use the authors found no over-stimulation, and cortisol output fell before recovering after a break. PMID 10341859
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
Hexarelin's plasma half-life is commonly reported at roughly 55-80 minutes, consistent with a short-acting, pulsatile GH-releasing profile and with the multiple daily administrations community sources describe. It is worth being precise about where that figure sits: the abstracts of the human hexarelin studies most often cited for it report GH response curves rather than a stated elimination half-life, so the number is best treated as a widely repeated approximation rather than a value traceable to a specific published human pharmacokinetic study. The functional observation behind it is not in doubt — the GH pulse rises and falls within hours — but if you see a precise half-life quoted to the minute, the useful question is which study measured it.
Reported side effects & toxicology
Human safety data are limited and derive mostly from short-term and single-dose studies. Among GHRPs, hexarelin is reported to have one of the highest tendencies to raise cortisol, prolactin and ACTH, and the paediatric literature measured those rises directly rather than inferring them. Other effects reported across the GHRP class include transient hunger, water retention, tingling or numbness, head rush and injection-site reactions. The most consequential limitation is attenuation of the GH response with continued use, and the shape of that attenuation is described in the next section rather than asserted here. These are reported observations from a thin human record, not a complete safety profile.
Storage & handling
Lyophilised: reported as stable refrigerated at 2-8°C and can be kept frozen for longer-term storage; keep sealed and protected from light and moisture until reconstituted.
Reconstituted: store refrigerated at 2-8°C, use within roughly 2-4 weeks, keep away from light, and do not freeze the reconstituted solution.
References
Built from primary sources: Bellone et al., JCEM 1995 (PMID 7714074, 96 children, 2 mcg/kg IV versus GHRH); Loche et al., JCEM 1995 (PMID 7673411, GH-deficient patients, hypothalamus-mediated response); Guzzaloni et al., J Pediatr Endocrinol Metab 2000 (PMID 10968479, prolactin and cortisol responses); Rahim and Shalet, Growth Hormone & IGF Research 1998 (PMID 10990150, the 16-week twice-daily subcutaneous study establishing partial, reversible attenuation); Arosio et al., J Endocrinol Invest 1998 (PMID 9624598, no effect on TRH-induced TSH); the current WADA Prohibited List; ClinicalTrials.gov, which lists no registered hexarelin trials; and the FDA drug-label database, which returns no hexarelin label. Registry and label status verified 12 August 2026. All figures are reported examples for educational use only and not medical advice.
Evidence File
Hexarelin Evidence File: Every Circulating Number Traced Back to Its Sentence
Hexarelin's human literature is small, old, and almost entirely quoted second hand. This file rebuilds it from the primary abstracts: what each study administered, to whom, by which route, and what it reported. It traces the figures the market repeats most often, the half-life, the potency ranking, the subcutaneous dose band and the cycle length, back to the sentence each one came from, including one case where a 2026 peer-reviewed review can be shown repeating the error. It names the exact registry queries behind the empty ClinicalTrials.gov result, records which development codes were searched, and sets out five places where the free guide's own cited papers do not say what the guide reports them as saying.
Zero registered trials across seven name forms, EP-23905 and MF-6003 included
Published human subcutaneous doses are per kilogram: 1.5 and 3 mcg/kg
The 55 minute half-life is the GH response decaying, not hexarelin
A third daily injection added nothing to 24-hour GH (PMID 11888836)
The Empty Registry, and the Name Forms It Was Searched Under
The First-in-Human Dose-Response, and the Genuinely Disputed Top of the Curve
The Sixteen-Week Study, and the Two Human Courses That Ran Longer
Two Injections a Day Versus Three: the Comparison Was Actually Run
Where the 55 to 80 Minute Half-Life Comes From, and Who Is Still Repeating It
The Only Human Head-to-Head, and What It Does to the Potency Ranking
Five Corrections to the Free Guide's Own Citations
Named Absences: the Searches, Stated as Searches
8 more sections in the Evidence File for Hexarelin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Hexarelin 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
Hexarelin Sourcing File: One Methyl Group, One Dalton, and the Salt Nobody Names
Hexarelin is unusually easy to substitute and unusually easy to mis-weigh, and the two problems hide behind different fields on a certificate. This file assembles the identity block from fetched database records, sets out the exact masses that separate hexarelin from the three peptides most often sold beside it, works the salt arithmetic line by line from a labelled milligram figure to the micrograms of peptide actually in the vial, and reads a constructed certificate field by field against those reference values. It also documents a naming ambiguity in the public chemistry databases themselves, and a status word in a federal registry, that a certificate can inherit without anybody noticing.
Hexarelin is GHRP-6 plus one CH2: exactly 14.0157 Da apart
One database name returns three masses spanning 887.0 to 1067.2
A 5 mg TFA di-salt vial holds about 20 percent less peptide than its label
No FDA substance registry record exists for any hexarelin salt form
The Identity Block, Field by Field, as Fetched
The Fourteen-Dalton Problem: Hexarelin Is GHRP-6 Plus One Methyl Group
The One-Dalton Problem: the Adduct That Is Never Named
The Epimer That No Certificate Catches
Salt Arithmetic: What a 5 mg Label Does Not Say
Three Molecular Weights Under One Name, and the Registry Word That Is Misread
A Constructed Certificate, Read Line by Line
7 more sections in the Sourcing File for Hexarelin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Hexarelin 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
Hexarelin Benefit Review: What Was Measured, in Whom, by Which Route
The growth hormone pulse hexarelin produces is real, large and reproducible, and it is the most securely evidenced thing about the compound. This review asks the separate question of what happened downstream when someone measured, and grades each marketed claim against what was actually measured, in whom, over what period and by which route. The downstream record splits cleanly along those last two axes, and the split is the reason the same claim can be found supported in one paper and null in another. It separates acute challenge findings from repeated dosing and from chronic dosing, and it identifies five populations in whom the response is blunted or absent, one of them defined by a variable most buyers can already measure.
At sixteen weeks: IGF-I, body fat, lean mass and bone density all unchanged
Chronic cortisol AUC fell 18.9 percent, and the authors call it not significant
Fat mass alone explained 61 percent of the variance in peak GH response
GH rose 19.6-fold in the study where cortisol rose 1.19-fold
The Adult Result: Sixteen Weeks, Twelve People, Four Outcomes, None Moved
The Result That Points the Other Way, and Why It Is Not a Contradiction
The Three Honest Objections to the Adult Null
Cortisol and Prolactin on Three Timescales, With Three Different Verdicts
The Two Ratios That Calibrate the Adrenal Claim
Five Populations in Whom the Response Is Blunted or Absent
The GHRH Pairing Is a Dose-Sparing Result, Not an Amplification Result
The Cardiovascular Thread: Real, Acute, and Null Where It Would Matter Most
Sleep, Appetite, and the Claims Graded Against What Was Measured
9 more sections in the Benefit & Outcome Review for Hexarelin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Hexarelin 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 the hexarelin dosage used in published human trials?
1-2 mcg/kg intravenously, given as a single challenge — approximately 70-140 mcg for a 70 kg adult — with an oral comparison at 10 mg. Those studies were diagnostic tests of pituitary responsiveness rather than treatment regimens. The subcutaneous figures that circulate in community sources are not the trial dose; they differ in route, frequency and duration.
How often is hexarelin dosed?
Community sources describe two to three subcutaneous administrations per day, on the reasoning that the GH pulse is short-lived. The only study that administered hexarelin repeatedly to humans dosed twice daily over 16 weeks. Three-times-daily schedules do not correspond to any published human protocol.
Does hexarelin stop working, and how long is a hexarelin cycle?
There is one human study of this, and it is unusually clear. Rahim and Shalet (Growth Hormone & IGF Research, 1998) gave twice-daily subcutaneous hexarelin to 12 healthy elderly participants for 16 weeks. The area under the GH curve fell from 19.1 at baseline to 13.1 at week 1, 12.3 at week 4 and 10.5 at week 16 — roughly a 45% decline, statistically significant from week 4 onward. Four weeks after the study ended hexarelin was administered again and the response had returned to 19.4, not significantly different from baseline. So the attenuation is real, sets in within the first week, is partial rather than total, and is fully reversible after a four-week break. Every 'cycle hexarelin' recommendation traces back to this trial, but the common 'two weeks on, two weeks off' pattern does not: the only measured recovery interval was four weeks.
How does hexarelin differ from GHRP-6 or ipamorelin?
Hexarelin is reported as the most potent of the group, producing larger GH pulses than GHRP-6 or GHRP-2 at equivalent molar doses. The trade-off is selectivity: it raises cortisol and prolactin more than milder options, and the paediatric trial data measured those rises rather than assuming them. Ipamorelin is the selective alternative — a smaller pulse without the same adrenal and prolactin signal. Choosing between them is choosing which side of that trade-off matters more.
Is hexarelin being studied in any current clinical trial?
No. A search of ClinicalTrials.gov for hexarelin as an intervention returns no registered studies. The human literature is concentrated in the 1990s and early 2000s, when it was investigated as a diagnostic GH-secretagogue and a potential therapeutic; that development did not continue. An empty trial registry alongside an active commercial market is worth noticing.
Is hexarelin legal or FDA-approved?
Hexarelin is not FDA-approved for any indication and the FDA drug-label database returns no hexarelin label. It is sold only for laboratory research use, not human consumption. It is explicitly named on the WADA Prohibited List (S2) and is banned for athletes both in and out of competition — research-grade labelling does not change that.
Why does hexarelin raise cortisol and prolactin?
Its action at GHS-R1a is not confined to the somatotroph population that releases growth hormone, and the ghrelin-receptor axis interacts with corticotroph and lactotroph signalling as well. The paediatric studies measured the result directly: a slight prolactin increase in both prepubertal and early pubertal children, with cortisol responses varying by pubertal stage. This is a property of the molecule rather than a dosing artefact, which is why it does not disappear at lower amounts.
Does hexarelin work through the pituitary or the hypothalamus?
Both, but the hypothalamic contribution appears necessary. In patients whose pituitary was anatomically disconnected from the hypothalamus — stalk interruption, pituitary cyst, empty sella — the GH response to hexarelin was absent or blunted, while patients with idiopathic GH deficiency responded normally. The authors read this as strong support for the GH-releasing effect of GHRPs being hypothalamus-mediated in humans.
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 Hexarelin. 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 Hexarelin
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.
