GHRP-6 is a synthetic hexapeptide, first described by Cyril Bowers’ group in 1984, that releases growth hormone by activating the ghrelin receptor.
The 1984 Endocrinology paper reported that His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 released growth hormone in rats, monkeys, lambs and calves without releasing LH, FSH, TSH or prolactin (Bowers et al., 1984). Merck researchers cloned the receptor these secretagogues act on in 1996 (Howard et al.), and its natural ligand, ghrelin, was identified in 1999 (Kojima et al.). Later studies use GHRP-6 as a ghrelin receptor agonist (Zheng et al., 2008).
Human data come from short studies. In 1989 a Smith Kline & French team infused GHRP-6 into 17 healthy men and recorded dose-related growth hormone rises (Ilson et al.), and a 1990 Tulane study found it acted synergistically with GHRH (Bowers et al., 1990). The appetite effect rests mainly on animal work: injected into the brain ventricles of rats, GHRP-6 triggered eating without changing plasma growth hormone (Locke et al., 1995).
No FDA-approved drug contains GHRP-6, the FDA lists it as a compounding safety risk, and WADA prohibits it in and out of competition.
The FDA added GHRP-6 to category 2 of its 503B compounding policy in September 2023, citing immunogenicity risk from aggregation and peptide-related impurities (FDA). WADA’s 2026 Prohibited List names GHRP-6 under section S2.2.4, growth hormone releasing factors, a non-Specified class banned at all times (WADA).
GHRP-6’s hunger effect is often treated as proof a vial is genuine. It is not. GHRP-2 also raised food intake in a 2005 human study (Laferrère et al.), and hexarelin differs from GHRP-6 by a single methyl group on one tryptophan. Hunger suggests something active at the ghrelin receptor; it does not show which peptide, how much of it, or what else is in the vial. An identity result from mass spectrometry and a measured purity figure answer those questions.
Check a batch’s published result before trusting its label. Recent certificates are on our latest tests page, and Janoshik’s public results database lets you look up a specific test. No results are published for GHRP-6 in our index yet. When the first published result arrives, a vendor leaderboard appears above.