Hexarelin Dosage Guide: Trial Doses, Cycle Evidence & Reconstitution

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

Commonly reported range

100-200 mcg per subcutaneous injection is the range described in community sources (not a recommendation, and not what the trials used)

Reported frequency

Community sources describe 2-3 times daily; the only chronic human study dosed twice daily

Reported cycle

Short cycles are near-universal advice; the single trial that measured this ran 16 weeks and found the blunting fully reversed after 4 weeks off

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

Reported ranges from research/community — examples, not recommendations.

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.

Dosage — reported ranges (overview)

There are two hexarelin dosage conversations and they do not describe the same thing. In the published human literature the dose was 1-2 mcg/kg given intravenously as a single challenge — roughly 70-140 mcg for a 70 kg adult — with an oral comparison at 10 mg. That was a diagnostic test of pituitary responsiveness, administered once, not a regimen. Community sources describe 100-200 mcg per subcutaneous injection given two to three times daily, with entry-level examples near 100 mcg once or twice daily. The numerical overlap is coincidental and slightly misleading: the community figure lands in the same range as the trial dose, but by a different route, at a different frequency, and repeated indefinitely rather than once. The only study that administered hexarelin subcutaneously on a repeated schedule in humans is the 16-week trial described below, and it dosed twice daily rather than three times. None of these figures is a recommendation, and the trial dose is not a licence to self-administer — it is context for reading the numbers everyone else quotes without provenance.

A printable protocol sheet with a reconstitution reference and an injection log comes with All-Access Lifetime.

Reconstitution — bac-water math

Hexarelin is supplied as a lyophilised (freeze-dried) powder and is reconstituted with bacteriostatic water before any measurement. Because it is dosed in micrograms, the useful figure is concentration in mcg per mL: concentration (mcg/mL) = (vial mg x 1000) / mL of water added. On a U-100 insulin syringe, 100 units = 1 mL, so a dose in units = dose (mcg) / concentration (mcg/mL) x 100. Worked example: a 5 mg vial reconstituted with 2 mL of water gives 5000 mcg / 2 mL = 2500 mcg/mL. A 200 mcg example would then be 200 / 2500 x 100 = 8 units on a U-100 syringe. Note how small these readings are — at 1 mL of water a 100 mcg example is 2 units, which is at the edge of what can be measured accurately on a standard insulin syringe. That is a practical argument for the larger water volumes in the table, and it is concentration math only, not a personal dose.

This is concentration math, not a dose recommendation.

Injection / administration basics

The published human studies administered hexarelin intravenously; the route community sources describe is subcutaneous injection with a U-100 insulin syringe into subcutaneous tissue such as the abdomen, with site rotation and standard aseptic handling. Because GHRPs are reported to blunt GH release when co-administered with food, sources commonly describe administration away from meals. This describes what is reported in a research context and is not instruction for human use.

Half-life & frequency rationale

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.

Stacking — overview

Hexarelin acts on GHS-R1a; GHRH analogs act on a complementary receptor, and the two are reported to amplify the GH pulse more together than either does alone. That is a general GHRP-plus-GHRH strategy rather than a hexarelin-specific clinical protocol, and hexarelin's stronger cortisol and prolactin profile is the reason many sources prefer a milder GHRP such as ipamorelin for extended work and reserve hexarelin for shorter runs. The pairings below reflect what is commonly described, not recommendations.

For how combinations are grouped by research context, the named blends, and why a pre-mixed blend vial cannot be calculated from its total milligrams, see the peptide stacks guide.

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.

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)

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 microgram amount a syringe actually delivers, 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 delivers 159 mcg where 200 mcg was calculated
• No FDA substance registry record exists for any hexarelin salt form

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

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