Hexarelin

Areas of active research — not promised effects

Each tag links to other compounds with research into that goal. Research use only: these are areas of study, not human-use claims.

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Hexarelin is not an FDA-approved drug and was not among the 19 peptides placed on the FDA 503A Category 2 bulk drug substances list in 2023 (fda19 flag: false). It has not been nominated or reviewed under any Section 503A or 503B pathway. It therefore exists in a strict research-use-only status: it may not be compounded as a prescription product, dispensed, or sold for human use. Legitimate procurement is limited to licensed research institutions for non-clinical laboratory research.

Transparent blend · bci-1.0 · never paid-placement

Primary name

Hexarelin

Origin

Hexarelin (examorelin; CAS 140703-51-1) is a fully synthetic six-amino-acid peptide developed by Mediolanum Farmaceutici in the early 1990s as a potent growth hormone secretagogue. It was designed to mimic the GH-releasing action of GHRH and ghrelin at the GHS-R1a receptor. Unlike endogenous ghrelin, hexarelin is not acylated and incorporates a 2-methyltryptophan residue that confers high receptor affinity and proteolytic resistance. It is structurally related to GHRP-2 and GHRP-6 but is generally regarded as the most potent member of the GHRP hexapeptide class. Hexarelin also binds the cardiac scavenger receptor CD36, a pharmacological property distinct from GHS-R1a-mediated GH release.

Registry IDs

PubChem CID

6918297

CAS

140703-51-1

InChIKey

RVWNMGKSNGWLOL-GIIHNPQRSA-N

DrugBank

DB19510

ChEMBL

CHEMBL108335

Molecular formula

C47H58N12O6

Molar mass

887.0 g/mol

Monoisotopic

886.46022762 Da

InChIKey

RVWNMGKSNGWLOL-GIIHNPQRSA-N

Appearance

White to off-white lyophilised powder

Solubility

Soluble in water and dilute aqueous acid (e.g. 0.1–1% acetic acid); limited solu…

Sequence not available in current seed.

Stability: Moderately stable in lyophilised form under cold, dry, dark conditions; susceptible to proteolytic degradation and aggregation in solution, particularly at elev

Vial sizes

2 mg · 5 mg

Purity grades

≥98% HPLC

Salt forms

Free base (primary)

• GHS hazard class on file
• PPE & spill response
• Disposal guidance
• Not-for-human-consumption posture

How much research exists, and of what maturity — never a verdict on whether it works.

Mechanism of action

• Hexarelin acts as a high-affinity agonist at GHS-R1a (the ghrelin receptor), a Gq/11-coupled receptor expressed on pituitary somatotrophs and hypothalamic arcuate neurons
• Binding activates phospholipase C, generates inositol trisphosphate, mobilises intracellular calcium, and triggers exocytosis of stored growth hormone while simultaneously potentiating endogenous GHRH signalling and partially suppressing somatostatin tone
• Hexarelin also activates the ERK1/2 (MAPK) pathway downstream of PKC and GHS-R1a engagement, contributing to proliferative and cytoprotective signalling in non-pituitary tissues
• A second pharmacological target, the cardiac scavenger receptor CD36, mediates direct cardioprotective effects — including positive inotropy, reduction of cardiomyocyte apoptosis following ischaemia–reperfusion injury, and modulation of coronary microvascular tone — independently of GH secretion

Pharmacokinetics (ADME)

Half-life

~55–76 min (species-dependent; ~55 min in humans by IV; ~76 min in rats by IV — PMID 10611139)

Clearance

Proteolytic and renal; subcutaneous bioavailability ~64% in rats (PMID 10611139); Cl/F dose-independent across SC dose range studied

PK–PD note: Peak GH response occurs ~30 min after IV administration in humans; GH returns to baseline within ~240 min. In rats, volume of distribution at steady state was 744 ± 81 mL/kg, suggesting broad tissue d…

Reading the evidence

• Evidence quality and gaps vary by application — see the cited grades above.
• Indexed-article counts span all evidence tiers, not only completed human trials.
• No first-party human-dosing, efficacy, or benefit claims are made here.

Key reviews & evidence-gap sources

• IUPHAR/BPS Guide to Pharmacology — Ghrelin receptor (GHSR) — Authoritative pharmacological annotation of the ghrelin/GHSR receptor target that hexarelin agonizes.
• Wikipedia — Growth hormone secretagogue receptor — Aggregator overview of GHSR and synthetic GHRPs (GHRP-6, hexarelin).
• Hexarelin improves lipid metabolic aberrations in MKR mice (PMC5659698) — Primary animal (mouse) mechanistic study, not a review; included as recent mechanistic reference and source of the Sivakumar 2011 systematic-review citation.
• Growth hormone-releasing activity of hexarelin in humans (Ghigo et al., 1994) — Foundational primary human pharmacology study; not a review.

No registered human trials found for this compound.

Status

No registered trials found

Summary (literature)

In the human pharmacological studies performed during development, hexarelin was generally well tolerated at single IV doses up to 2 mcg/kg in healthy adults. The most consistently reported effects are transient cortisol and prolactin elevation, which are more pronounced than tho…

WADA status

Prohibited at all times (in- and out-of-competition) under WADA 2026 Prohibited List, Section S2 — Peptide Hormones, Growth Factors, Related Substances and Mime…

Dominant research route: Subcutaneous (most cited in PK/disposition literature, with the rat DMD kinetics study and the human Ghigo 1994 crossover both anchoring SC); intravenous is the reference comparator route.

Human — 12 healthy young volunteers; IV doses of 1 and 2 μg/kg evaluated for GH-releasing activity (Ghigo et al., 1994, J Clin Endocrinol Metab).

Bioavailability: Reference (100%) route for GH-releasing activity comparisons in the human multi-route study; IV saline used as negative control.

Comparative study design (not an RCT); IV served as the reference comparator for SC, IN, and PO routes in the same subjects.

Human — 12 healthy young volunteers; SC doses of 1.5 and 3 μg/kg (Ghigo et al., 1994). Rat PK — SC bioavailability ~64%, rapidly absorbed, first-order kinetics up to 50 μg/kg (Drug Metab Dispos, rats).

Bioavailability: In rats, SC absolute bioavailability approximately 64% (DMD rat kinetics study). In humans, SC GH-releasing activity compared against IV in the same crossover study.

Most frequently cited route in PK literature; rat disposition study indicates biliary excretion as primary elimination pathway and rapid SC absorption.

Human — 12 healthy young volunteers at 20 μg/kg (Ghigo et al., 1994); short children growth-promotion trial (Laron et al., 1995, Clin Endocrinol); elderly subjects short-term IN dosing without GH-response desensitization (Ghigo et al., 1996, Eur J Endocrinol).

Bioavailability: IN route demonstrated GH-releasing activity in man; no absolute bioavailability figure retrieved from primary sources.

Multiple independent human studies confirm IN activity; Laron 1995 was a clinical trial in short children, Ghigo 1996 a clinical trial in aging subjects.

Human — 12 healthy young volunteers at 20 and 40 mg (Ghigo et al., 1994); oral bioavailability factors evaluated in man (Westberg et al., 2001, J Pharm Pharmacol).

Bioavailability: Biological bioavailability (estimated from GH levels) of 0.3 ± 0.1% after oral administration in man (Westberg 2001).

Oral activity demonstrated but with very low biological bioavailability; Westberg 2001 attributes this to degradation by gastrointestinal enzymes and poor membrane permeability. Oral-stability note (not absorption): hexarelin is susceptible to GI enzymatic degradation.

Not established in retrieved primary literature; appears only in non-primary aggregator/community sources.

Bioavailability: No peer-reviewed PK or bioavailability figure retrieved for IM hexarelin.

Community/aggregator sources mention IM injection, but no primary human or animal PK study was located; treat as unsourced anecdote.

Animal & human figures are kept visibly separate so studied animal doses are never misread as human guidance.

Sorted A–Z by vendor — never by price

Weekly median $/mg from the live vendor crawl.

Researched storefront prices, bucketed

p25 $7.45 · median $9.20 · p75 $9.90 · 8 researched vendors

Legit, COA-backed band: $6.90–$9.99/mg.

Value rule: don't just buy the cheapest — a price under $3/mg is a red flag. Pair price with COA and independent-test grade.

Estimated cost of research (10 mg)

Vial (best researched price)

$58

Bacteriostatic water (generic estimate)

$6

Syringes / supplies (generic estimate)

$12

What each test proves — general guidance, plus this compound's researched purity data

Purity on the current market (researched)

Vendor-posted third-party (Janoshik/HPLC) Certificates of Analysis for Hexarelin report purity of 99.3–99.5% (e.g., Skye Peptides batch HEX25-5-001: 99.5%; Philadelphia Peptides: 99.3%; Peptide.co lot YPB.261: 99.4%). These are vendor-published COAs, not an independent cross-vendor aggregate, and were not independently retrieved from the issuing lab.

Independent labs cited for this compound

No hexarelin-specific FDA recalls, seizures, warning letters, or criminal enforcement actions were found in FDA enforcement databases or the web search record. None found.

Buyer red-flag checklist

• Hexarelin is not an FDA-approved drug; sold as 'research use only' but frequently marketed with drug-like structure/function claims that trigger unapproved-new-drug status.
• Explicitly prohibited by WADA at all times (S2.3) — risk of anti-doping sanctions.
• HPLC 'purity ≥99%' reflects only UV-detectable species; peptide content can be diluted with non-UV-active fillers (e.g., mannitol) without lowering the purity figure, enabling underdosing that purity testing alone misses.
• Gray-market peptide supply chain has no mandatory testing or FDA oversight; vendor-posted COAs may be forged, cherry-picked, or batch-specific and not representative of ongoing production.
• Janoshik (the primary independent testing option) lacks ISO 17025 accreditation and methodology detail on COAs; results would not be accepted for regulatory submissions.
• No hexarelin-specific enforcement, recall, or counterfeit seizure record was found — absence of enforcement does not indicate absence of risk in an unregulated market.

GMP vs research-grade: the chemistry (SPPS + HPLC + MS) is identical — the difference is the quality system.

Underdosing / mislabeling: No hexarelin-specific underdosing prevalence was found in independent lab data. As an aggregate (not compound-specific) reference, Janoshik Analytical reported that 43% of peptides tested in 2024 failed to meet label purity claims, with lower-tier gray-market vendors showing actual purities of 71–91% despite claiming 99%+. This figure spans all peptides, not Hexarelin specifically.

• Detention Without Physical Examination of Unapproved New Drugs Promoted In The U.S. Authorizes DWPE of unapproved new drug imports; revised 05/19/2026, published 06/24/2026. General unapproved-new-drug authority — Hexarelin is not individually named on the Red List.66-41
• An RUO label is not an import exemption — CBP judges actual intended use.
• Lyophilized powder is ambient-stable in transit; temperature control needed for > 7-day transit.
• US-warehouse vendors dodge import scrutiny — they cost more but ship more reliably.

Every item dated & sourced

Prohibited at all times — S2.2.4 Growth Hormone Releasing Factors; examorelin (hexarelin) explicitly named as a GH-releasing peptide (GHRP) on the WADA 2026 Prohibited List.

No granted patents identified in current seed. Composition-of-matter coverage is limited given the peptide's synthetic origin.

• IACUC / IRB research context
• RUO buyer responsibilities & documentation
• Veterinary / alternative-use where lawful
• Jurisdiction-aware "who may lawfully obtain"

What people discuss

Reported concerns — discussion, not established effects

Reading caveats

• Vendor-affiliated subreddits (ParamountPeptide, USPeptides) publishing promotional guides
• Self-reported anecdotal experiences without controls or blinding
• Survivorship bias in positive testimonials (dissatisfied users less likely to post)
• Aggregator sites (peptides.org, muscleandbrawn) with affiliate links to vendors
• Potency reputation may amplify expectation/placebo effects

Manually researched from reddit, youtube, x— theme weights are research estimates, not live counts; aggregated & de-identified. No individual posts, quotes, or usernames are ever shown.

Relative research / market volume — populated once the activity stream is wired

Inline tooltips for lyophilized, RUO, EU/mg, SPPS, 503A and more.

Toggle plain-language ↔ scientific in the header.

• How to read a COA
• Free base vs acetate
• Understanding evidence grades

Potent synthetic hexapeptide GHS-R1a / CD36 dual agonist that stimulates GH release and exerts direct cardioprotective effects; research use only. Approximately 311 articles are indexed (literature last scanned 2026-05-29). US regulatory status: Not FDA-approved; never nominated for 503A Category 2; RUO only. Research use only.

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