GHRP-6
GHRP-6 is a synthetic hexapeptide that helped establish the growth hormone secretagogue field after its description in the 1980s. It reliably releases growth hormone and strongly stimulates appetite via ghrelin-receptor activation, but it has never been approved for any therapeutic indication; human data come mainly from pharmacology and physiology studies.
Mechanism
In plain terms, GHRP-6 acts like the hunger hormone ghrelin, prompting the pituitary to release growth hormone and increasing appetite. Technically, it is a synthetic hexapeptide agonist of the growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor); receptor activation on pituitary somatotrophs drives pulsatile growth hormone release, while central ghrelin-receptor signalling stimulates food intake. It can also cause modest increases in prolactin and cortisol.
Regulatory Status by Region
- United States (FDA)Not approved for any indication; an unapproved growth hormone secretagogue with no marketed product.
- Australia (TGA)Not on the Australian Register of Therapeutic Goods (ARTG); an unapproved substance with no registered product.
- European Union (EMA)No EMA marketing authorisation; not an approved medicine in the EU.
- WADAProhibited at all times under Section S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics); growth hormone secretagogues including GHRP-6 are explicitly covered.
Key Studies
- On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone (original description of the growth hormone-releasing hexapeptide later known as GHRP-6) (Bowers CY, Momany FA, Reynolds GA, Hong A. Endocrinology. 1984.)