Hexarelin
Performance, Muscle Building
In short
- The most potent GH-releasing peptide of the GHRP family on a weight basis.
- Notable for rapid desensitisation — GH response falls substantially with continued daily use, more so than the other GHRPs.
- Has documented cardiac effects independent of GH, mediated through CD36, and was studied for cardioprotection.
- Raises cortisol and prolactin, similar to GHRP-2.
- Prohibited at all times in sport under WADA class S2.
Structure
How it works
Hexarelin is a synthetic hexapeptide agonist at GHS-R1a, producing strong GH release. It also binds CD36, a scavenger receptor expressed in cardiac tissue, which is the basis for the cardiovascular effects reported independently of growth hormone.
The CD36 interaction distinguishes it from the rest of the class and is why it was investigated for cardioprotection rather than only for GH release.
What the research shows
Human studies confirm potent GH release, with the notable finding that the response attenuates markedly during continued daily administration — reported reductions of well over half within a couple of weeks in some studies.
Cardiac studies reported improvements in left ventricular function in some settings, including in GH-deficient adults. This literature is small and did not lead to approval.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — GH release studies | 1–2 µg/kg produces robust GH response | intravenous or subcutaneous | PubMed |
| Human — desensitisation studies over continued dosing | GH response substantially attenuated during repeated daily administration | — | PubMed |
| Human — cardiac function studies | See source for administered schedules | — | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported, usually in short courses | 100 µg, one to two times daily | subcutaneous |
No published human pharmacokinetic study establishes a dose, interval, or duration for this compound. Community figures below have no trial behind them and are reports of practice, not evidence. The desensitisation finding is the practically important one here: continuous daily use is documented to reduce the GH response over time, which is why short courses are the commonly described pattern.
Handling and storage
Supplied as a lyophilised powder requiring reconstitution with bacteriostatic water. The powder is comparatively stable; once reconstituted it is refrigerated and used within weeks. Track the date you reconstitute each vial — the Inventory section does this, and it is the difference between knowing a vial is three weeks old and guessing.
Subcutaneous injection. Short courses with breaks are the usual described pattern, reasoned from the documented desensitisation rather than from a dosing study.
Side effects
Reported: flushing, head-rush, water retention, increased appetite, and tingling in the extremities. Cortisol and prolactin elevation occur.
The cardiac activity via CD36 cuts both ways — it was the basis for investigating cardioprotection, and it also means this compound has direct cardiovascular activity that the other GHRPs do not, which has not been characterised for long-term use in healthy people.
Combinations
Paired with GHRH analogues on the usual two-receptor rationale. Stacking with other GHRPs is redundant at the receptor and adds cortisol load.
Given the desensitisation profile, rotating within the GHRP class rather than combining is the more commonly described approach.
Research status
Studied through the 1990s and 2000s for GH release, cardiac function, and CD36 biology, largely by Italian and Canadian groups. Never approved.
Legal status
Not approved for human use in any jurisdiction. Sold for research use only.
WADA status
PROHIBITED AT ALL TIMES under WADA class S2 — growth hormone secretagogues, their releasing factors and mimetics are explicitly named. Any tested athlete should treat this as an anti-doping violation.
Conclusion
Hexarelin is the strongest GH releaser in the family and the one that stops working fastest, which is an awkward combination. Its CD36-mediated cardiac activity makes it pharmacologically the most interesting GHRP and also the least characterised for casual use.
Sources
Track your own Hexarelin protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.