Hexarelin

Hexarelin (also known as examorelin) is a synthetic, orally active growth hormone-releasing hexapeptide. It acts as a potent agonist of the ghrelin/growth hormone secretagogue receptor (GHSR) to stimulate the release of growth hormone (GH).

Key Benefits

• May support natural growth hormone release and IGF-1 production
• Commonly researched for improving muscle growth, recovery, and strength development
• May help support tissue repair and recovery following physical stress or injury
• Research suggests potential benefits for body composition, healthy aging, and cardiovascular support

FDA-Approved Uses

Regulatory status (as of May 2026):
– FDA views GH secretagogues as Investigational New Drugs (INDs)
– Hexarelin is NOT on the 503A Bulks List (Category 1) — no confirmed legal 503A compounding pathway
– No PCAC review scheduled for hexarelin specifically as of May 2026
– Status: Grey-market research compound only

Key GHRP class position:
– HIGHEST raw GH output of all injectable GHRPs at equivalent doses
– BUT: FASTEST receptor desensitization (downregulation within 1–2 weeks of continuous use)
– Significant cortisol and prolactin elevation (more than ipamorelin; similar to GHRP-6)
– Less appetite stimulation than GHRP-6 (moderate advantage)

Trade Names in the USA and Manufacturers

No FDA-approved trade name or manufacturer in USA.

Development history:
– Originally formulated in the mid-1980s by Dr. Cyril Bowers and colleagues at Tulane Medical School, New Orleans, LA — seeking a potent GH secretagogue with improved half-life
– Further developed and studied by researchers at the University of Milan (Italy) and Mediolanum Farmaceutici (Milan, Italy)
– INN (International Non-proprietary Name): Examorelin
– Also referred to as developmental codes: EP-23905 and MF-6003

Molecular identity:
– Synthetic hexapeptide (6 amino acids)
– Sequence: His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂
– Derived from GHRP-6 (His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂)
– Key structural difference from GHRP-6: D-tryptophan at position 2 replaced with D-2-methyltryptophan
– This single modification significantly increases potency and half-life vs. GHRP-6
– MW: ~887 Daltons

US availability:
– Grey-market research peptide vendors: Available as lyophilized powder (‘research use only’)
– No licensed 503A compounding pharmacy access (not on Category 1 Bulks List)
– No clinical trial active in US as of May 2026

Dosage

⚠️ No FDA-approved dosing. All protocols from research and grey-market community use.

STRONG CAUTION ON CYCLE LENGTH — Hexarelin desensitizes GHRSR-1a receptors faster than any other GHRP. GH response diminishes significantly after 1–2 weeks of daily use; longer cycles substantially reduce effectiveness.

Subcutaneous injection:
Dose per injection: 100–200 mcg
Frequency: 2–3 times daily (every 3–4 hours for multiple daily protocols)
OR once daily (lower frequency, reduced desensitization risk)
Timing: Upon waking, post-workout, and/or at bedtime
Cycle: Maximum 4–6 weeks (some protocols: 2–4 weeks)
Rest period: Equal time off (minimum 4 weeks)

Key difference from Ipamorelin / CJC-1295:
Ipamorelin: Slow desensitization → can sustain longer cycles
Hexarelin: RAPID desensitization → strict short cycles mandatory for maintained effectiveness

Combination protocols:
Hexarelin 100 mcg + GHRH analogue (CJC-1295 100 mcg) per injection
GHRH + GHRP combination amplifies GH output (synergistic effect)
⚠️ Combined GH output with hexarelin is exceptionally high — monitor for excessive GH/IGF-1

Reconstitution:
Lyophilized powder; reconstitute with Bacteriostatic Water
Store at -20°C lyophilized; stable in solution 14–21 days at 4°C

Pricing

No FDA-approved commercial pricing.

Research peptide vendors (unregulated):
Typical vials: 2 mg, 5 mg
Per vial: ~$30–$60 (5 mg)
Monthly cost at standard protocols: ~$100–$250/month
[Generally priced similarly to GHRP-2 and GHRP-6; slightly higher than ipamorelin in some vendors]

No 503A compounding source available.
All sources are grey-market / research use only.

Tips

• Hexarelin’s primary practical limitation is RAPID DESENSITIZATION. Unlike ipamorelin (which can sustain longer protocols), hexarelin’s effectiveness drops significantly after 1–2 weeks of continuous daily use. Strictly limit cycles to 2–6 weeks with equal time off.
• If body composition improvement is the goal and cortisol elevation is a concern: Ipamorelin is a cleaner GHRP choice (no meaningful cortisol or prolactin elevation). Hexarelin’s higher cortisol burden may offset some anabolic benefits.
• Hexarelin’s UNIQUE ADVANTAGE: CD36 receptor activity, cardiovascular effects not shared by other GHRPs. For patients with interest in the cardiovascular/cardioprotective research angle (atherosclerosis, post-ischemic cardiac recovery), hexarelin is the only GHRP with this secondary mechanism.
• Monitor IGF-1 every 4–6 weeks during use. Do not allow IGF-1 to exceed the upper limit of the normal reference range — elevated IGF-1 carries theoretical cancer risk.
• Cortisol and prolactin elevation: These hormonal effects are less pronounced than with GHRP-6 but more pronounced than with ipamorelin. Patients with anxiety, cortisol-related conditions, or adrenal considerations should prefer ipamorelin.

Side Effects

From Phase 1–2 clinical research (Mediolanum Farmaceutici, Italian university studies) and community use:

Hormonal effects (class-level concern):
– Cortisol elevation: Dose-dependent increase in cortisol — more pronounced than ipamorelin; similar to GHRP-6. Stimulates HPA axis via arginine vasopressin (AVP) pathway (distinct from GH-releasing mechanism)
– Prolactin elevation: Mild-to-moderate; dose-dependent; less clinically significant than cortisol
– ACTH elevation: Associated with HPA stimulation

Common:
– Injection site reactions: Redness, swelling, mild pain (most common)
– Facial flushing / warmth post-injection
– Mild headache (transient)
– Water retention / peripheral edema: GH-mediated; more pronounced in first 2–4 weeks
– Mild increased appetite: Less than GHRP-6 (lower ghrelin mimicry); more than ipamorelin
– Vivid dreams (GH pulse during deep sleep)

Less common:
– Elevated blood glucose / insulin resistance: GH elevation; less concern at short cycles than with continuous use
– Elevated IGF-1: Theoretical cancer risk with sustained elevation
– Numbness / tingling (paresthesia): Fluid retention

Contraindications

No formal FDA contraindications (no approved label).

Based on pharmacology and clinical exclusion criteria:

Absolute avoid:
– Active malignancy or significant cancer history: GH/IGF-1 elevation may promote tumor growth
– Athletes subject to WADA/USADA testing: S2 prohibited at all times — absolute contraindication
– Pregnancy and breastfeeding: No safety data

Use with caution:
– Diabetes mellitus or insulin resistance: GH worsens glucose metabolism; monitor blood glucose
– Anxiety disorders or HPA axis disorders: Cortisol and ACTH elevation may worsen symptoms
– Cardiovascular disease: While CD36 activity may be cardioprotective in theory, the cortisol and fluid retention effects are unfavorable in cardiac patients; use with caution
– Children with open epiphyses: Risk of abnormal linear growth from GH excess
– Active intracranial lesion or pituitary tumor
– Hypothyroidism (untreated): Blunts GH response; correct first
– Hypersensitivity to hexarelin or its components

Pharmacology

Hexarelin (INN: Examorelin) is a synthetic hexapeptide (6 amino acids) GHRP and selective ghrelin receptor (GHSR-1a) agonist. Sequence: His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂. MW ~887 Daltons. Derived from GHRP-6 with a key substitution: D-tryptophan (position 2) → D-2-methyltryptophan. This modification significantly increases potency and enzymatic stability vs. GHRP-6.

Unique dual receptor activity (distinguishes from all other GHRPs):
1. GHSR-1a (ghrelin receptor): Same target as ipamorelin, GHRP-2, GHRP-6 → GH release
2. CD36 receptor (scavenger receptor): Expressed in cardiac tissue, macrophages, and fat cells. Hexarelin is the ONLY GHRP known to also activate CD36 — explaining its unique cardiovascular effects not shared by other GHRPs.

Pharmacokinetics: Short plasma half-life (~30–60 min); rapid pituitary effect; produces transient GH pulse. Administered subcutaneously or IV (research). Lyophilized powder; reconstituted with Bacteriostatic Water; stable in solution 14–21 days at 4°C.

Mechanism of action

Hexarelin acts through two distinct receptor systems:

1. GHSR-1a (Ghrelin Receptor) — Primary GH-releasing mechanism:
Binding → phospholipase C activation (Gq/11 pathway) → IP3/DAG → intracellular Ca²⁺ release → GH synthesis and release from pituitary somatotrophs
ALSO activates hypothalamic GHSR-1a → GHRH release + somatostatin suppression → dual hypothalamic/pituitary GH amplification
Result: HIGHEST GH output per dose of any injectable GHRP in the class
Rapid GHSR-1a desensitization: Receptor downregulation begins within days of continuous use — explains why short cycles are mandatory

2. CD36 (Cardiac/Macrophage Scavenger Receptor) — Cardiovascular mechanism:
Hexarelin binds CD36 in cardiac ventricles, atria, aorta, and coronary vessels (highest concentration in ventricles)
CD36 activation: Prevents oxidized LDL (oxLDL) uptake into macrophages → reduces foam cell formation → anti-atherosclerotic effect
Cardioprotective effects in ischemia/reperfusion models: Reduces cardiomyocyte apoptosis, improves cardiac function post-MI
This CD36 pathway is INDEPENDENT of GH/IGF-1 — occurring even at non-GH-releasing doses

3. HPA Axis Activation (side effect mechanism):
Hexarelin stimulates ACTH and cortisol release via arginine vasopressin (AVP) pathway — distinct from the GH-releasing GHSR-1a pathway
This is the mechanism underlying hexarelin’s cortisol and prolactin side effects that exceed those of ipamorelin

Result Claims from Different Companies

Mediolanum Farmaceutici / University of Milan (primary research):

Clinical GH stimulation studies (human):
– Dose-dependent, statistically significant GH increases in both healthy adults and GH-deficient patients
– GH response to hexarelin exceeds that of GHRP-6 at equivalent doses — confirmed in direct comparison studies
– GH response exceeds GHRH alone at equivalent doses in adult sham-operated rats; in vivo comparison in humans also favored hexarelin
– PubMed-indexed studies (1990s–2000s): Established hexarelin as potent GHSR-1a agonist with specific HPA axis effects

Cardiovascular research:
– Mao et al. (Journal of Geriatric Cardiology): Documented CD36-mediated cardiovascular effects; hexarelin shown to improve cardiac function in ischemia models independent of GH
– ScienceDirect overview (2024 reference): ‘Hexarelin has been shown to improve atherosclerotic lesions by its ability to bind the scavenger receptor CD36, preventing the uptake of oxidized LDL’

Comparative GHRP class position (from research community consensus):
– ‘Hexarelin exceeds GHRP-6 in raw GH output but produces the fastest desensitization and the heaviest cortisol burden’
– GH output ranking: Hexarelin > GHRP-6 ≈ GHRP-2 > Ipamorelin
– Cortisol burden ranking: Hexarelin ≈ GHRP-6 > GHRP-2 >> Ipamorelin
– Appetite stimulation: GHRP-6 >> Hexarelin ≈ GHRP-2 >> Ipamorelin
– Desensitization speed: Hexarelin >> all others (fastest)

Disclaimer

This content about “Hexarelin (Examorelin / INN) Synthetic Hexapeptide GHRP (GHRP-6 Analogue)” is for informational and educational purposes only, is not medical advice, does not replace consultation with a licensed healthcare professional, and affiliate links may result in compensation at no additional cost to you.