Hexarelin

Structure: Synthetic hexapeptide (His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2). Binds the ghrelin receptor (GHSR-1a) for GH release and the CD36 scavenger receptor for cardiovascular effects.

Dosage:

• Standard GH effect: 100mcg 1 to 3 times per day, SubQ
• Cardioprotective angle (anecdotal): 50 to 100mcg 1 to 2 times per day
• Cycle: 4 weeks on, 4 weeks off (mandatory due to rapid receptor desensitisation)

Administration:

• SubQ injection, 27 to 30g insulin syringe
• Take on empty stomach (food blunts GH response)
• Pre-bed dose captures natural sleep GH pulse
• Reconstitute with bacteriostatic water, refrigerate

Key Notes:

• Strongest acute GH releaser of the early GHRPs (Hexarelin > GHRP-2 > GHRP-6 > Ipamorelin in raw GH amplitude).
• Severe receptor desensitisation: continuous use beyond ~4 weeks blunts the GH response sharply. Mandatory cycling distinguishes it from Ipamorelin (which is much more forgiving).
• Cortisol and prolactin elevation is meaningful. Not a "clean" GHRP. Avoid if prolactin or cortisol are already elevated (e.g. on 19-nor compounds like nandrolone or trenbolone).
• Cardioprotective effect via CD36 is genuinely interesting and not shared by Ipamorelin or MK-677. Small human trials show improved left ventricular function after acute administration. This is the unique selling point versus other GHRPs.
• Largely superseded by Ipamorelin (cleaner) and MK-677 (oral, more convenient) for general GH optimisation.
• Often stacked with a GHRH analog (CJC-1295 without DAC, Tesamorelin) for additive GH release.
• Monitor: IGF-1, cortisol, prolactin, fasting glucose.

References:

• Locatelli, V., Rossoni, G., Schweiger, F., Torsello, A., De Gennaro Colonna, V., Bernareggi, M., Deghenghi, R., Müller, E. E., & Berti, F. (1999). Growth hormone-independent cardioprotective effects of hexarelin in the rat. Endocrinology, 140(9), 4024-4031. DOI: 10.1210/endo.140.9.6948
• Imbimbo, B. P., Mant, T., Edwards, M., Amin, D., Dalton, N., Boutignon, F., Lenaerts, V., Wüthrich, P., & Deghenghi, R. (1994). Growth hormone-releasing activity of hexarelin in humans. European Journal of Clinical Pharmacology, 46(5), 421-425. DOI: 10.1007/BF00191904
• Bisi, G., Podio, V., Valetto, M. R., Broglio, F., Bertuccio, G., Aimaretti, G., Pelosi, E., Del Rio, G., Muccioli, G., Ong, H., Boghen, M. F., Deghenghi, R., & Ghigo, E. (1999). Cardiac effects of hexarelin in hypopituitary adults. European Journal of Pharmacology, 381(1), 31-38. DOI: 10.1016/S0014-2999(99)00543-8
• Rahim, A., O'Neill, P. A., & Shalet, S. M. (1998). Growth hormone status during long-term hexarelin therapy. Journal of Clinical Endocrinology and Metabolism, 83(5), 1644-1649. DOI: 10.1210/jcem.83.5.4812