Hexarelin
A potent synthetic growth-hormone-releasing peptide (GHRP) that strongly stimulates the body’s own GH. It is among the most powerful of the GHRPs but is prone to tolerance and to raising cortisol and prolactin. Not an approved drug.
Quick take
- What it is: a potent synthetic growth-hormone-releasing peptide (GHRP) that mimics ghrelin.
- What people use it for: strongly stimulating natural GH release for recovery and body composition.
- What we actually know: it raises GH powerfully short-term, but tends to lose effect over time and can raise cortisol and prolactin.
- Status: not FDA-approved and banned in competitive sport.
What it is
Hexarelin is a synthetic growth-hormone-releasing peptide (GHRP) — a short peptide that mimics the hormone ghrelin and stimulates the pituitary to release the body’s own growth hormone (GH). It is generally regarded as one of the most potent of the GHRPs.1
That potency comes with trade-offs: Hexarelin is less selective than newer secretagogues, more likely to also raise cortisol and prolactin, and notably prone to tolerance (a fading response) with repeated use.
How it works
Hexarelin binds the ghrelin/GH-secretagogue receptor and triggers a strong pulse of GH release, which raises IGF-1.1,2 Because it acts on a different receptor than GHRH analogues (such as CJC-1295 or sermorelin), it is sometimes discussed in combination with that class. Hexarelin has also drawn research interest for possible direct effects on cardiac and vascular tissue independent of GH, though that work is preliminary.
What the evidence shows
Animal studies
Preclinical studies show potent GH release and have explored Hexarelin’s cardiovascular effects, which appear partly independent of GH.2 These findings are mechanistically interesting but early.
Human studies
Short-term human studies confirm that Hexarelin strongly raises GH, but they also document desensitization — a decline in the GH response with continued administration — and effects on cortisol and prolactin.3 There are no long-duration outcome trials establishing benefit for recovery, body composition or aging, and long-term safety is not characterized. Popular use rests on short-term physiology plus anecdote.
Dosages reported in the literature
Informational only. The figures below describe doses reported in research and clinical settings. They are not a recommendation or a prescription, and appropriate use should be determined by a qualified healthcare professional who can account for your individual situation.
| Setting | Route | Reported range |
|---|---|---|
| Research | Subcutaneous / IV | Microgram-per-kilogram amounts as single or short-term doses |
| Anecdotal / clinic-reported | Subcutaneous | Commonly ~100 mcg per dose, one to several times daily |
Reported protocols vary, and the tendency toward tolerance complicates any sustained-use schedule. None are supported by long-term outcome trials.
Safety & side effects
Reported short-term side effects include injection-site reactions, flushing, headache and water retention. Distinctive concerns for Hexarelin specifically are elevations in cortisol and prolactin (more than with selective secretagogues) and desensitization with continued use.3 Its cardiovascular effects are under study and not fully understood. Because there are no long-term controlled human studies, the overall risk profile is not well characterized.
As with all peptides from the unregulated market, product purity and dose accuracy vary between sources.
Legal & regulatory status
Hexarelin is not approved by the FDA for any use. It is banned in competitive sport — the World Anti-Doping Agency prohibits growth-hormone secretagogues at all times (category S2).4 Rules vary by country and change over time.
References
- Berlanga-Acosta J, Abreu-Cruz A, Garcia-del Barco Herrera D, et al. Synthetic Growth Hormone-Releasing Peptides (GHRPs): A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects. Clin Med Insights Cardiol. 2017;11:1179546817694558. [PMID 28469491, doi:10.1177/1179546817694558]
- Locatelli V, Rossoni G, Schweiger F, Torsello A, De Gennaro Colonna V, Bernareggi M, Deghenghi R, Muller EE, Berti F. Growth hormone-independent cardioprotective effects of hexarelin in the rat. Endocrinology. 1999 Sep;140(9):4024-4031. [PMID 10465272, doi:10.1210/endo.140.9.6948]
- Massoud AF, Hindmarsh PC, Brook CG. Hexarelin-induced growth hormone, cortisol, and prolactin release: a dose-response study. J Clin Endocrinol Metab. 1996 Dec;81(12):4338-4341. [PMID 8954038, doi:10.1210/jcem.81.12.8954038]
- World Anti-Doping Agency. The Prohibited List — S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics (GH-releasing peptides [GHRPs] including examorelin [hexarelin] prohibited at all times). WADA, 2026. [wada-ama.org]