A synthetic hexapeptide growth hormone secretagogue (a GHRP) that acts on the ghrelin/GHS receptor to potently release growth hormone, studied mostly in 1990s-2000s human pharmacology work.
Reviewed for accuracy · Last reviewed July 8, 2026Hexarelin is a synthetic hexapeptide that acts on the growth hormone secretagogue (ghrelin) receptor to trigger growth hormone release from the pituitary. In human studies it released roughly twice the GH of an equal dose of GHRH, which is why it is grouped with the GH-secretagogue peptides alongside sermorelin, tesamorelin, and CJC-1295/ipamorelin. It has real human pharmacology data but was never developed into an approved therapeutic product.
Beyond GH, hexarelin also transiently raises cortisol and prolactin, and a small set of studies reported short-lasting positive effects on cardiac contractility that appear largely independent of GH. A known caveat for this whole peptide class is that the GH-releasing effect tends to attenuate (partially desensitize) with continued use, more so with continuous than intermittent dosing.
Human studies gave hexarelin intravenously at roughly 1 to 2 mcg/kg (about 100 mcg) and subcutaneously at similar mcg/kg doses. It is investigational, so there is no approved dose, and the GH response can attenuate with continued use.
Read the full Hexarelin dosage guide →Reported effects include facial flushing, transient rises in cortisol and prolactin, and injection-site reactions. As a GH-secretagogue class effect, water retention and changes in insulin sensitivity are also discussed.
Read the full Hexarelin side effects guide →Keep unmixed vials refrigerated and away from light. Once reconstituted, peptides like this are generally kept refrigerated and used within a few weeks. See the full storage & safety guide for handling and disposal basics.
This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Talk to a doctor before starting any compound.