Hexarelin

Hexarelin, also known as examorelin or exarelin, is a synthetic six-amino-acid methylated relative of GHRP-6. It stimulates the ghrelin/secretagogue receptor and is marketed for recovery/body composition despite never becoming an approved drug.

It also binds CD36 in cardiovascular tissue. Repeated exposure can partially reduce the GH response; that does not establish irreversible receptor burnout or a validated cycling schedule.

One study in healthy men found that hexarelin produced a larger GH rise than GHRH and acted synergistically with it. This was a study-specific hormone response, rather than a clinical outcome or a universal potency ranking. An acute seven-adult IV comparison found similar GH responses to hexarelin and GHRP-2 under its conditions, with prolactin, ACTH and cortisol increases. This does not support universal potency ranking, GH-only selectivity or a standard subcutaneous half-life.

The 16-week study did not find significant changes in total body fat, lean mass or bone density. IGF-I and IGFBP-3 were not significantly changed over 20 weeks. Biological activity is distinct from an established muscle/recovery outcome.

In seven young volunteers, repeated evening IV exposure reduced first-half-night stage-4 sleep and overall EEG delta power while raising several hormones. That finding does not support a general deep-sleep benefit.

In 24 men undergoing coronary bypass, acute IV exposure briefly improved ejection fraction, cardiac index and output while also increasing mean arterial pressure. It was not a chronic event-reduction study.

Rat membrane/perfused-heart experiments identified CD36 involvement and increased coronary perfusion pressure, absent in CD36-deficient hearts. A receptor or vasoconstrictive response is not automatically human cardioprotection.

The longer study used 1.5 micrograms/kg subcutaneously twice daily. Mean GH-response areas were 19.1, 13.1, 12.3 and 10.5 micrograms/L·hour at baseline and weeks 1, 4 and 16, returning to 19.4 four weeks after treatment. Weeks 4 and 16, but not week 1, were identified as significant decreases in the abstract. A related 12-person report described partial, reversible attenuation; these should not be counted as separate large trials.

Shorter studies maintained GH responses in seven older adults over 8 days intranasally and seven older women over 15 days orally. Oral treatment slightly increased IGF-I/IGFBP-3, with no prolactin/cortisol change or side effects reported. Small short studies cannot establish chronic SC safety.

The sleep experiment used four 50-microgram IV doses; the surgical study used 2 micrograms/kg IV. Those routes and populations do not define a general injection amount, pre-workout/bedtime rule, stack or receptor-reset calendar.

Hexarelin has no FDA approval and is described as ineligible for routine 503A compounding. It is not approved for performance or anti-aging, and WADA prohibits hexarelin/examorelin at all times.

Acute non-GH hormone responses and the unfavorable sleep finding remain important. No side effects in small short oral/intranasal studies is not proof of rare-event safety, years of use or superiority to GHRP-2/GHRP-6. The marketed clinical benefits remain unproven.