Hexarelin
Also known as Examorelin, EP 23905, Hexarelin acetate
Hexarelin is the most potent of the growth hormone releasing peptides on a per dose basis, with a larger pulse than GHRP-2 or GHRP-6. The trade offs are a rise in cortisol and prolactin and the fastest receptor desensitization in the class, which is why it is run in short cycles.
Reviewed by the amino101 editorial team. .
Quick start
What people commonly do. Not a prescription.- Typical dose
- 100 to 200 mcg
- How often
- 1 to 3 times daily
- Where
- Subcutaneous, belly or thigh
- Timing
- Empty stomach, most often before bed; no food for 20 to 30 minutes after; extra doses on waking or after training
- Effects timeline
- flushing and a short burst of hunger within the hour, deeper sleep in the first week, IGF-1 rise by 2 to 4 weeks, then a fading response after week 4
- Storage
- Lyophilized in freezer or fridge away from light; reconstituted in fridge 2 to 8 C, use within 4 weeks
- Cycle length
- 4 to 8 weeks
- Break between
- at least 4 weeks, often filled with ipamorelin
A 2 mg vial in 1 mL gives 2 mg per mL, so 100 mcg is 5 units and 200 mcg is 10 units on an insulin syringe.
Overview
Hexarelin is a synthetic hexapeptide developed in the early 1990s as a more stable analog of GHRP-6, with a methylated tryptophan that makes it more resistant to breakdown. Human studies by Ezio Ghigo's group in Turin showed strong growth hormone release by intravenous, subcutaneous, intranasal and oral routes, and for a while it was the most studied GHRP in European clinical research. It was never approved. Pharmaceutical development stalled in the late 1990s and it has lived in the research market since.
Two findings define how it is used. First, in a 16 week study in healthy men, the growth hormone response to hexarelin fell substantially by week 4 and only partly recovered, with IGF-1 drifting back toward baseline. That desensitization is faster and deeper than with ipamorelin or GHRP-2, so long runs are pointless. Second, hexarelin has effects on the heart that do not depend on growth hormone. In rats it protected heart muscle during ischemia, and in a small human study a single dose raised left ventricular ejection fraction in patients with coronary artery disease. The cardiac work is interesting but small, and no trial has tested chronic use for any heart condition.
In the community hexarelin is run at 100 to 200 mcg one to three times daily, in cycles of 4 to 8 weeks, usually alongside a GHRH analog. People pick it for maximum growth hormone output in a short window, accept the cortisol and prolactin, and rotate to ipamorelin for longer phases. It raises cortisol and prolactin more than GHRP-2 does. This page is educational; it reports what appears in research and community use, not what anyone should take.
How it works
Hexarelin is a potent agonist at the growth hormone secretagogue receptor, GHS-R1a. In the pituitary it triggers growth hormone release directly; in the hypothalamus it stimulates GHRH neurons and suppresses somatostatin, which amplifies the pulse and explains the synergy with GHRH analogs. It is less selective than ipamorelin and activates pathways that release ACTH, cortisol and prolactin. With daily dosing the receptor downregulates and the growth hormone response shrinks over weeks, which is the desensitization problem. Separately, hexarelin binds CD36, a scavenger receptor on heart muscle and blood vessels, and this rather than growth hormone appears to mediate the cardioprotective effects seen in animals.
Where the research stands
Growth hormone releaseStrong evidence
- Dose dependent GH pulse. Multiple human studies show the largest pulse of any GHRP by several routes, with the response fading over weeks of daily use.
- Synergy with GHRH analogs. Human data show the GHRP plus GHRH combination releases more than the sum of either alone.
Heart protectionEmerging
- Ischemia protection. Rat studies show protection of heart muscle through CD36 independent of growth hormone; a single dose human study found a short term rise in ejection fraction in coronary disease.
Body composition and recoveryEmerging
- Lean mass and recovery. No human outcome trials; the 16 week study showed IGF-1 did not stay elevated, which argues against large body composition effects.
Growth hormone deficiency diagnosisModerate evidence
- Stimulation testing. Studied as a diagnostic agent in children and adults in the 1990s with good discrimination, but never adopted into guidelines.
- human RCTHexarelin produced strong, dose dependent growth hormone release in healthy adults by intravenous, subcutaneous, intranasal and oral routes.
- human pilotOver 16 weeks of twice daily subcutaneous hexarelin in healthy men, the growth hormone response was markedly attenuated by week 4 and IGF-1 did not stay elevated.
- human pilotA single intravenous dose of hexarelin increased left ventricular ejection fraction in patients with coronary artery disease, independent of growth hormone.
- rodentHexarelin protected the heart against ischemia and reperfusion injury in rats, including in animals without a functioning growth hormone axis.
- in vitroCD36 was identified as the receptor mediating the direct cardiac effects of growth hormone releasing peptides.
- human RCTAcross acute human studies, hexarelin raised cortisol and prolactin alongside growth hormone, more than GHRP-2 and far more than ipamorelin.
Rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Levels over time
Modeled from the half-life. Illustrative, not measured.A half-life of 1 h against dosing every 24 h means each dose has cleared before the next. Nothing stacks; you start from zero every time, and the tissue effect is what carries over.
The pulse is short and sharp, so one to three doses a day do not overlap. The practical limit is not the half-life but the receptor, which stops responding after a few weeks of daily dosing.
Hexarelin dosage and protocols
Short cycles are the rule: 4 to 8 weeks of daily dosing, then at least 4 weeks off. The human 16 week study is the reason, since the growth hormone response had fallen markedly by week 4. Many people use hexarelin as a short high output block within a longer ipamorelin or GHRP-2 run, then rotate back. Bloodwork for IGF-1, prolactin and morning cortisol is sensible at the end of a block.
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Stacked with a GHRH analog | 100 mcg | once daily before bed, with 100 mcg CJC-1295 no DAC | Subcutaneous, same syringe |
| Solo nightly dose | 200 mcg | once daily before bed | Subcutaneous |
| Short high output block | 100 mcg | 3 times daily for 4 weeks, on waking, after training, before bed | Subcutaneous |
| Every other day to slow desensitization | 100 to 200 mcg | once every other day before bed | Subcutaneous |
Fasted dosing matters: eating within 30 minutes on either side blunts the pulse. Bedtime lines up with the natural nighttime surge and a post-training dose is common because somatostatin is low after exercise. Some people dose every other day on the theory that it slows receptor downregulation, which is plausible but untested. When stacked with a GHRH analog, both go in one syringe.
Trials used about 1 to 2 mcg per kg, which lands at 100 to 200 mcg for most adults. More than 200 mcg adds cortisol and prolactin without much extra growth hormone.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 2 mg | 1 mL | 2 mg/mL | 5 units |
| 5 mg | 2 mL | 2.5 mg/mL | 4 units |
How to reconstitute Hexarelin
- 1
Wash your hands and wipe the work surface. Swab both vial stoppers with alcohol and let them dry.
- 2
Pick the water volume with the calculator above and write it on the vial. The concentration means nothing without it.
- 3
Draw the bacteriostatic water into a mixing syringe.
- 4
Insert at an angle and let the water run down the inside wall. Never squirt it straight onto the powder.
- 5
Swirl gently or leave it to dissolve. Do not shake.
- 6
Label with the date and water volume. Store in the fridge at 2 to 8 C and use within about 4 weeks.
- 7
Unmixed vials keep for months in the fridge and longer in the freezer, sealed and out of light.
- Full walkthrough with syringe reading and site rotation: reconstitution guide.
- ✓White, fluffy cake
Lyophilized powder should look like a small white puck or fluffy cake at the bottom of the vial. That is a proper freeze-dry.
- ✓Clear after mixing
Once dissolved the solution should be water-clear with nothing floating in it.
- !Slight clumping
Small clumps that dissolve with gentle swirling are fine. Shipping compacts powder.
- ✕Collapsed or melted
Powder stuck to the sides, glassy, or shrunken means it got hot in transit. Contact the vendor.
- ✕Cloudy or particles
Persistent cloudiness or visible particles after mixing means degraded or contaminated product. Do not use it.
- Week 1 to 2
The strongest response of the cycle: flushing, a short burst of hunger, deeper sleep and vivid dreams, some water retention at higher doses.
- Week 2 to 4
IGF-1 measurably higher on bloodwork, recovery feels quicker, early side effects settle; the pulse is already starting to shrink by the end of this window.
- Week 4 to 8
Diminishing returns as the receptor downregulates; cortisol and prolactin related complaints surface in the people prone to them, and most people stop or rotate here.
Interactions and stacking
CJC-1295 (no DAC)synergistic
The standard pairing; GHRH receptor plus ghrelin receptor gives the largest pulse available from secretagogues.
Sermorelinsynergistic
Same two pathway synergy with a milder GHRH analog.
Ipamorelincompatible
Same receptor, so they are rotated rather than combined; ipamorelin fills the break between hexarelin blocks.
GHRP-2compatible
Same receptor and same side effect family; no reason to run both at once.
HGHcaution
Exogenous growth hormone suppresses the pituitary, leaving little for a secretagogue to release.
Insulin and diabetes medicationscaution
Growth hormone and cortisol both raise glucose for hours after a dose; monitor if you take anything that lowers blood sugar.
Food and sugary drinks near the doseavoid
Insulin and free fatty acids after a meal cut the pulse substantially.
The standard pairing. A GHRH analog on a different receptor multiplies the hexarelin pulse, and the combination gives the largest single pulse available from secretagogues.
Rotation rather than combination: hexarelin for a short high output block, then ipamorelin for longer phases while the ghrelin receptor recovers.
Safety
- ▲Flushing, headache or lightheadedness in the first hour
- ▲Short burst of hunger after a dose, milder than GHRP-6
- ▲Water retention and puffy hands at higher doses
- ▲Tingling in the fingers when stacked heavily
- ▲Raised cortisol, felt by some as restlessness or poorer sleep from daytime doses
- ▲Raised prolactin, which can show as reduced libido or breast tenderness
- ▲Desensitizes faster than any other GHRP. Human data show the response dropping within 4 weeks of daily use, so long cycles waste the compound.
- ▲Raises cortisol and prolactin more than GHRP-2 and far more than ipamorelin; long runs can show up as sleep, mood, libido or breast tissue problems.
- ▲Prohibited in sport by WADA under S2 as a growth hormone releasing peptide.
- ▲The cardiac findings are from rats and one small human study; nobody should use it for a heart condition on that basis.
- ▲Growth hormone pulses raise blood glucose for several hours; people with insulin resistance should watch bloodwork.
- ▲Avoid raising growth hormone and IGF-1 with any active or prior hormone sensitive cancer.
- ■Breast tenderness or nipple changes, which point to prolactin
- ■Numbness or carpal tunnel symptoms that persist after lowering the dose
- ■Fasting glucose or HbA1c rising on bloodwork
- ■IGF-1 above the reference range for your age
- ■Chest pain, palpitations or any new cardiac symptom, since it acts directly on heart tissue
Community poll
Self-reported by visitors. Not clinical evidence.Hexarelin: frequently asked
What hexarelin dosage appears in research and protocols?
Clinical studies used roughly 1 to 2 mcg per kg, which works out to 100 to 200 mcg for most adults, and community protocols report the same range one to three times daily. Going above 200 mcg mostly adds cortisol and prolactin. When stacked with a GHRH analog the common pairing is 100 mcg of each.
Why do people cycle hexarelin so short?
Because the receptor stops responding. In a 16 week human study the growth hormone response had fallen markedly by week 4 and IGF-1 drifted back toward where it started. Community cycles of 4 to 8 weeks followed by a month or more off are an attempt to work around that. Rotating to ipamorelin during the break is common.
Is hexarelin good for the heart?
There is a genuine signal in animals, where hexarelin protected heart muscle during ischemia through a receptor called CD36 rather than through growth hormone, and a small human study found a short term rise in ejection fraction after one dose. That is a long way from evidence that chronic use helps anyone. Treat it as an interesting research finding, not a reason to use it.
Hexarelin or GHRP-2?
Hexarelin gives the bigger pulse and the faster desensitization; GHRP-2 is a little weaker but holds up better over a cycle and causes more hunger. Many people use hexarelin for a short block when they want maximum output, then switch to GHRP-2 or ipamorelin for the longer stretch.
References
- Growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal, and oral administration in man. Journal of Clinical Endocrinology and Metabolism, 1994
- Growth hormone status during long-term hexarelin therapy. Journal of Clinical Endocrinology and Metabolism, 1998
- Effects of acute hexarelin administration on cardiac performance in patients with coronary artery disease. Journal of Clinical Endocrinology and Metabolism, 2002
- Growth hormone-independent cardioprotective effects of hexarelin in the rat. Endocrinology, 1999
- CD36 mediates the cardiovascular action of growth hormone-releasing peptides in the heart. Circulation Research, 2002