Growth hormone secretagogue · Also known as Growth Hormone Releasing Peptide-6, Growth Hormone Releasing Hexapeptide, GHRP6
A synthetic hexapeptide that stimulates the pituitary gland to release growth hormone by activating the ghrelin receptor (GHS-R1a). It produces strong GH pulses along with a notable increase in appetite, making it distinct from more selective secretagogues like ipamorelin.
GHRP-6 was one of the first growth hormone secretagogues developed, emerging from research in the 1980s and 1990s on synthetic met-enkephalin analogs. It helped establish the ghrelin receptor pathway as a target for GH stimulation and paved the way for newer, more selective peptides. Clinical pharmacokinetic studies in healthy volunteers have confirmed its safety profile and GH-releasing potency.
GHRP-6 binds to the growth hormone secretagogue receptor (GHS-R1a), the same receptor targeted by the body's natural hunger hormone ghrelin. This triggers a signaling cascade involving protein kinase C and calcium mobilization (independent of the cAMP pathway used by GHRH), resulting in a powerful pulse of growth hormone from the pituitary. The effect is amplified when combined with endogenous GHRH.
Because GHRP-6 activates the ghrelin receptor, it also stimulates appetite centers in the hypothalamus, producing noticeable hunger within 15 to 30 minutes of injection. It additionally causes modest, transient increases in cortisol and prolactin at doses above 100 mcg. The distribution half-life is about 8 minutes with an elimination half-life of roughly 2.5 hours, so multiple daily doses are needed to sustain elevated GH output.
100 mcg 2x/day
Weeks 1-4100 mcg 2-3x/day
8-12 week cyclesMost side effects tend to improve as your body adjusts.