Hexarelin: uses, evidence and status

compound file

The answer, first. A synthetic hexapeptide close in structure to GHRP-6, methylated for greater potency. Studied in Italian and British human experiments through the 1990s, never approved. The strongest evidence is for growth hormone release, graded B — one well-powered human trial. Twelve men, double-blind and placebo-controlled.

Intravenous doses of 0.5, 1 and 2 micrograms per kilogram lifted peak GH from 3.9 to 26.9, 52.3 and 55.0 nanograms per millilitre ².

The curve plateaus near 1 microgram per kilogram. The other use — body composition in adults — grades D or E: a claim the human trials have already tested and not supported.

What it is used for

Every use graded on its own evidence, not the compound as a whole. 5 outcomes, ranked by what the human record supports.

#outcome · human · animal · gradewhat the best evidence actually shows

01Growth hormone release12 men, double-blind · extensivegrade BTwelve men, double-blind and placebo-controlled. Intravenous doses of 0.5, 1 and 2 micrograms per kilogram lifted peak GH from 3.9 to 26.9, 52.3 and 55.0 nanograms per millilitre ². The curve plateaus near 1 microgram per kilogram.

02Sustained GH release over months16 weeks, single-arm · matchinggrade CThe response fades. Sixteen weeks of twice-daily subcutaneous hexarelin at 1.5 micrograms per kilogram cut the GH area under the curve by nearly half ³. From 19.1 to 10.5 micrograms per litre per hour, recovering four weeks after stopping.

03Growth and skinfold in short children8 children, open-label · supportinggrade CEight short children on intranasal hexarelin, 60 micrograms per kilogram three times daily for up to eight months. IGF-I rose 10.4 to 14.1 nanomoles per litre and growth velocity 5.3 to 8.3 centimetres a year ⁵. Skinfold thickness fell. Uncontrolled.

04Cardiac contractility24 bypass patients · rat infarct modelsgrade CTwenty-four men with coronary artery disease, during bypass surgery. Two micrograms per kilogram intravenously raised ejection fraction, cardiac index and cardiac output within 10 minutes ⁶. The rise held 90 minutes. Growth hormone and GHRH did not produce it ⁷.

05Body composition in adults16 weeks, measured · no outcome datagrade EMeasured directly and nothing moved. Across the same 16 weeks, total body fat, lean body mass, bone mineral density, IGF-I and IGFBP-3 were all unchanged from baseline ³. Single-arm, no placebo group.

gradewhat it means

ARegulatory approval, or multiple adequately-powered trials agreeing with each other

BAt least one well-powered human randomised trial, with the direction replicated

CSmall or open-label human trials only

DAnimal or mechanism data only, with no controlled human outcome

EA claim the human trials have already killed

How it works

The proposed mechanism, in three steps. A mechanism is a reason to run a trial, never a substitute for one.

1targetBinds the growth hormone secretagogue receptor GHSR-1a on pituitary and hypothalamus, and separate secretagogue receptors on myocardium.

2signalDrives a GH pulse that is dose-dependent to a ceiling near 1 microgram per kilogram, with prolactin and cortisol on their own curves.

3effectRepeated dosing partly desensitises the pituitary inside four weeks, and the response recovers four weeks after stopping.

What it does not do

Claims the current record does not support. Worth knowing before you set expectations.

not supported by the evidence

Builds muscle in adults. Measured and absent. Sixteen weeks of twice-daily subcutaneous dosing left lean body mass and total body fat unchanged ³.
Raises IGF-1 over a cycle. Sixteen weeks of dosing left IGF-I and IGFBP-3 unchanged across 20 weeks of follow-up in the same adults ³.
The GH response holds if you keep dosing. It roughly halves. The GH area under the curve fell from 19.1 to 10.5 micrograms per litre per hour by week 16 ³.
Selective for growth hormone. Prolactin peaked 180 percent above baseline and cortisol stepped up about 40 percent, both dose-dependently ⁴¹¹.

How it is used

What published protocols administered, and what the community reports doing. Descriptive on both counts, and never a recommendation.

routeSubcutaneous injection in the community record. Published human work used intravenous, subcutaneous, intranasal and oral routes.

formatLyophilised powder in a multi-dose vial, reconstituted with bacteriostatic water. Sold by the milligram.

published dosesHuman studies used intravenous 0.5 to 2 micrograms per kilogram, subcutaneous 1.5 to 3, intranasal 20, and oral 20 to 40 milligrams ¹². Bioavailability was 77 percent subcutaneously, 4.8 percent nasally, 0.3 percent orally ¹. The 16-week study dosed 1.5 micrograms per kilogram subcutaneously twice daily ³.

human pharmacokineticsPlasma GH peaks near 30 minutes and returns to baseline by 240 minutes, decay half-life about 55 minutes ². Hexarelin's own half-life is unpublished.

reported conventionsAs reported on bodybuilding forums catalogued in a 2026 clinical review, 2025 to 2026: 100 to 200 micrograms subcutaneously, one or two injections a day. Cycles run eight to twelve weeks with four weeks off ⁸. That review presents these as behavioural data, not treatment strategies. Convention, not guidance.

commonly paired withCJC-1295

This site does not publish protocols to follow. The doses above are what studies administered or what users report, stated as facts about the literature and the market. How protocols are structured, mixing and storage and the reconstitution calculator cover the arithmetic.

What to expect

Where a trial measured it, the trial. Where only the community reports it, that is said out loud.

onsetGH peaks about 30 minutes after an intravenous dose and is back to baseline by four hours ². Cardiac output rose inside 10 minutes and held 90 minutes in bypass patients ⁶. The GH response is already significantly smaller by week four ³.

most common reportAs reported: a flush and a head rush after injection, and hunger. The measured effects are a GH pulse with prolactin and cortisol alongside it.

adverse effectsProlactin rose 180 percent and cortisol about 40 percent above baseline, dose-dependently, in a human dose-response study ⁴. Subcutaneous bioavailability is 77 percent, so an injected dose carries the full endocrine load ¹. As reported: flushing, hunger, water retention.

the stop signalNo trial defined a stop rule. The published stop signal is pharmacological: the GH response roughly halves by week 16 and needs about four weeks off to recover ³.

Approval and status

What regulators and sport bodies have actually said, separately from what the evidence shows.

approvalNot approved anywhere, for any indication.

FDANot approved. Not named on FDA's compounding category 2 list as of 22 April 2026, which is an absence of review rather than an endorsement ⁹.

sport [WADA]Prohibited at all times under S2.2.4, named as examorelin ¹⁰. Urinary metabolites are mapped ¹².

sold asresearch chemical

Check the vial

The grade above describes a molecule studied under controlled conditions. It says nothing about the powder in a particular vial.

That gap is the one part of this market a reader can actually close. How to read a certificate of analysis covers the five measures in five minutes, and the 2026 audit grades vendors on the documents they publish against a rubric printed in full.

Questions we get

What is Hexarelin used for?

Raising growth hormone, and per microgram it is the most potent of the peptide secretagogues studied in people. Twelve men, double-blind: 1 microgram per kilogram intravenously took peak GH from 3.9 to 52.3 nanograms per millilitre ².

It also raises cardiac output independently of growth hormone ⁶. What it did not do, over 16 weeks in adults, is change lean mass or body fat ³.

How is Hexarelin used?

Published human work covered four routes. Intravenous 0.5 to 2 micrograms per kilogram, subcutaneous 1.5 to 3, intranasal 20, oral 20 to 40 milligrams ¹².

Bioavailability was 77 percent subcutaneously, 4.8 percent nasally, 0.3 percent orally ¹. The 16-week study used 1.5 micrograms per kilogram subcutaneously twice daily ³. As reported on forums catalogued in a 2026 review: 100 to 200 micrograms subcutaneously once or twice daily ⁸. Convention, not guidance.

How long does Hexarelin take to work?

GH peaks about 30 minutes after an intravenous dose and is back to baseline by four hours ². Cardiac output rose inside 10 minutes in bypass patients ⁶.

The more useful number runs the other way. The GH response is already significantly smaller by week four and roughly halved by week 16 ³. It recovers four weeks after the last dose.

Is Hexarelin an approved drug?

No. Hexarelin is sold as a research chemical, not as an approved medicine. On our index it is graded early human on clinical evidence and niche on community adoption, and those two are rated separately on purpose.

It is not named on FDA's compounding category 2 list, which is an absence of review rather than an endorsement ⁹. It is prohibited in sport at all times as examorelin ¹⁰.

References

Ghigo E, Arvat E, Gianotti L, et al. Growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal and oral administration in man. J Clin Endocrinol Metab. 1994;78:693-698. PMID 8126144
Imbimbo BP, Mant T, Edwards M, et al. Growth hormone-releasing activity of hexarelin in humans. A dose-response study. Eur J Clin Pharmacol. 1994;46:421-425. PMID 7957536
Rahim A, O'Neill PA, Shalet SM. Growth hormone status during long-term hexarelin therapy. J Clin Endocrinol Metab. 1998;83:1644-1649. PMID 9589671
Massoud AF, Hindmarsh PC, Brook CG. Hexarelin-induced growth hormone, cortisol and prolactin release: a dose-response study. J Clin Endocrinol Metab. 1996;81:4338-4341. PMID 8954038
Laron Z, Frenkel J, Deghenghi R, et al. Intranasal administration of the GHRP hexarelin accelerates growth in short children. Clin Endocrinol [Oxf]. 1995;43:631-635. PMID 8548949
Broglio F, Guarracino F, Benso A, et al. Effects of acute hexarelin administration on cardiac performance in patients with coronary artery disease during by-pass surgery. Eur J Pharmacol. 2002;448:193-200. PMID 12144941
Bisi G, Podio V, Valetto MR, et al. Cardiac effects of hexarelin in hypopituitary adults. Eur J Pharmacol. 1999;381:31-38. PMID 10528131
Dominikowski A, Rekos Z, Olejarz M, et al. The emerging landscape of performance-enhancing peptides modulating the GH-IGF1 axis. Front Endocrinol. 2026;17:1822475. PMID 42395176
US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of 22 April 2026. fda.gov
World Anti-Doping Agency. Prohibited List 2026, International Standard, effective 1 January 2026. wada-ama.org
Arvat E, di Vito L, Maccagno B, et al. Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Peptides. 1997;18:885-891. PMID 9285939
Semenistaya E, Zvereva I, Thomas A, et al. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, hexarelin and ipamorelin. Drug Test Anal. 2015;7:919-925. PMID 25869809

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