Hexarelin
Examorelin · Hex
The most potent GHRP, and the fastest to stop working if you run it continuously.
Typical dose
100 mcg
1-2x daily
Range
50–200
mcg
Half-life
55 min
see Dosing
Evidence
Early human
Subcutaneous · Intramuscular · Intranasal · Intravenous
What it is
Hexarelin is GHRP-6 with a methyl group added to the tryptophan at position two, a small change that makes it the most potent of the classic growth hormone releasing peptides. Microgram for microgram it produces the largest GH pulse of the four, and it was studied in humans through the 1990s by intravenous, subcutaneous, intranasal and even oral routes.
The catch is tachyphylaxis. Sixteen weeks of twice-daily subcutaneous hexarelin in adults roughly halved the GH response to a test dose, with the decline already significant by week four. Four weeks after stopping, the response had recovered to baseline. Hexarelin is a short-cycle compound: run continuously it fades, and building the break in is the single most important thing to plan around.
It also raises cortisol, ACTH and prolactin more than GHRP-2 at comparable GH output. Separately it binds CD36 in cardiac tissue, a GH-independent mechanism behind a body of cardioprotective animal work that is interesting but not a reason to run it.
How it works
Hexarelin agonises GHS-R1a on pituitary somatotrophs and in the hypothalamus, releasing GH directly and lifting the somatostatin brake. Mechanically it is the same as the other GHRPs, just with higher affinity and higher efficacy at the receptor.
That extra potency costs selectivity: hexarelin drives the corticotroph and lactotroph response harder, so ACTH, cortisol and prolactin rise more than they would for an equivalent GH pulse from ipamorelin. Sustained receptor exposure downregulates the response, which is why GH output fades over weeks rather than months.
Dosing
Twice daily is the practical ceiling. Three or more doses a day accelerates desensitisation without adding meaningful GH, and the cycle break is not optional with this one.
Reconstitution calculator
Pre-loaded with Hexarelin’s vial size, water volume and typical dose. Change anything.
Typical: 100 mcg · range 50–200
Draw to
10 u
0.1 mL · 100 mcg
Concentration
1 mg/mL
10 mcg per unit
Doses per vial
20
Vial lasts
10 days
Draw to 10 units on the barrel.
Once mixed
Store at 2-8 C out of light and use within 3-4 weeks. Do not freeze once reconstituted.
Run the bacteriostatic water down the vial wall and swirl until dissolved, never shake. A 2 mg vial in 2 mL gives 1,000 mcg/mL, so a 100 mcg dose is a clean 10 units on a 100-unit insulin syringe.
Storage
Before mixing
Keeps for months sealed and dry at 2-8 C and for years at -20 C; short room-temperature shipping does no real harm.
After mixing
Store at 2-8 C out of light and use within 3-4 weeks. Do not freeze once reconstituted.
Reported benefits
- ▪Largest GH pulse per microgram of any of the classic GHRPs
- ▪Well documented in human studies across IV, subcutaneous and intranasal routes
- ▪Strong synergy with GHRH analogues for short, high-output blocks
- ▪Milder appetite stimulation than GHRP-6
- ▪GH-independent cardiac effects via CD36 in a sizeable animal literature
- ▪Effective at low absolute doses, so a 2 mg vial goes a long way
Side effects
- ▪Rapid desensitisation, with the GH response measurably blunted within weeks of continuous use
- ▪The largest cortisol, ACTH and prolactin rise of the four GHRPs
- ▪Water retention and puffy hands
- ▪Head rush, flushing and sweating shortly after injecting
- ▪Tingling or numb fingers, more common than with the milder GHRPs
- ▪Reduced insulin sensitivity on longer runs
- ▪Lethargy or low libido if prolactin climbs
Do not use if
- ▪Active or suspected malignancy
- ▪Uncontrolled diabetes or significant insulin resistance
- ▪Existing hyperprolactinaemia or any adrenal disorder
- ▪Untreated pituitary or hypothalamic disease
- ▪Pregnancy and breastfeeding
Evidence level — Early human
Small or early-phase human studies only.
Not approved for human use in any market, sold as a research chemical, and prohibited by WADA at all times.
Commonly run with
CJC-1295 no-DAC
Short-acting GHRH fragment that sharpens one GH pulse, almost always run with a GHRP.
100 mcg · 1-3x daily
CJC-1295 with DAC
Albumin-binding GHRH analogue that lifts GH and IGF-1 for days from one injection.
1000 mcg · 1-2x weekly
Sermorelin
The first 29 amino acids of human GHRH, once approved as Geref and now compounded.
300 mcg · once nightly, 5-7 nights per week
Tesamorelin
The only FDA-approved GHRH analogue, proven to shrink visceral abdominal fat.
2 mg · once daily
Hexarelin FAQ
How fast does hexarelin actually stop working?+
Human data on twice-daily subcutaneous dosing at 1.5 mcg/kg showed the GH response already significantly reduced by week four and roughly halved by week sixteen. Four weeks after stopping it had returned to baseline. Most people plan four to six week blocks with a full month off rather than testing where their own ceiling is.
Is it worth it over GHRP-2?+
Only for short blocks where peak GH output is the point. Hexarelin gives a bigger pulse but carries more cortisol and prolactin and desensitises far faster. For anything you intend to run for months, GHRP-2 or ipamorelin is the more sensible tool.
Does the cortisol rise matter at 100 mcg?+
In a healthy person a single 100 mcg dose produces a modest, transient ACTH and cortisol bump. It matters more when you dose twice daily for weeks, are already in a large calorie deficit, or are running anything else that pushes cortisol. Watch sleep, mood and recovery as your early warning.
What about the heart claims?+
Hexarelin binds CD36 in cardiac tissue independently of GH, and animal studies show reduced infarct size and improved cardiac function. None of that has been established in humans at the doses used here, so treat it as an interesting mechanism rather than a benefit you are buying.
Can I stack it with another GHRP?+
No. They compete for the same receptor, so you get no additive GH and a faster path to desensitisation. The productive stack is a GHRP with a GHRH analogue such as CJC-1295 no-DAC, which acts on a different receptor entirely.
References
- 1.Growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal, and oral administration in man — The Journal of Clinical Endocrinology and Metabolism (1994) PMID 8126144
- 2.Growth hormone-releasing activity of hexarelin in humans. A dose-response study — European Journal of Clinical Pharmacology (1994) PMID 7957536
- 3.Growth hormone status during long-term hexarelin therapy — The Journal of Clinical Endocrinology and Metabolism (1998) PMID 9589671
More gh secretagogues
CJC-1295 no-DAC
Short-acting GHRH fragment that sharpens one GH pulse, almost always run with a GHRP.
100 mcg · 1-3x daily
CJC-1295 with DAC
Albumin-binding GHRH analogue that lifts GH and IGF-1 for days from one injection.
1000 mcg · 1-2x weekly
GHRP-2
Potent, well-studied GHRP with a bigger pulse than ipamorelin and more cortisol.
100 mcg · 2-3x daily
GHRP-6
The original GHRP: solid GH release and the strongest hunger response of the group.
100 mcg · 2-3x daily