What it is

GHRP-6 is the hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. It fits the ghrelin receptor GHS-R1a in the pituitary and hypothalamus, and it also binds CD36, a scavenger receptor on heart and blood vessel cells. The first gives the growth hormone pulse and hunger; the second gives a separate tissue-protective effect. In people it clears from the blood within about an hour.