{"id":"ghrp-6","name":"GHRP-6","aliases":["GH-releasing peptide-6","His-D-Trp-Ala-Trp-D-Phe-Lys"],"url":"https://lyoresearch.com/compounds/ghrp-6","class":{"id":"gh-secretagogues","name":"GH secretagogues (GHRPs)","url":"https://lyoresearch.com/classes/gh-secretagogues"},"summary":"GHRP-6 is the first of the growth-hormone-releasing peptides, a synthetic six-amino-acid ghrelin mimic. In studies it raises growth hormone as reliably as the standard insulin tolerance test, which makes it a useful diagnostic; it also stimulates appetite. As with the rest of its class, there is no controlled human trial showing it builds muscle or reduces fat, and it is banned in sport.","overall_grade":"C","overall_grade_meaning":"weak human evidence","human_trials":"Diagnostic studies + small work","regulatory_status":"Not approved","molecule":{"formula":"C46H56N12O6","molecular_weight":"873.0","cas":null,"pubchem_cid":4345065,"note":null},"pharmacokinetics":{"basis":"human","route":"Intravenous bolus (9 healthy men)","half_life":"About 2.5 hours elimination half-life; distribution half-life about 8 minutes","licensed_regimen":null,"product":null,"source":{"title":"Cabrales A, et al. Pharmacokinetic study of growth hormone-releasing peptide 6 (GHRP-6) in nine male healthy volunteers. Eur J Pharm Sci 2013;48:40–46","url":"https://pubmed.ncbi.nlm.nih.gov/23099431/"}},"outcomes":[{"outcome":"Growth hormone release (diagnostic)","grade":"B","grade_meaning":"probable, not settled","effect_size":"moderate","adverse":false,"human_studies":"Diagnostic comparison studies","evidence":"GHRP-6, alone or with GHRH, stimulated growth hormone as sensitively and specifically as the insulin tolerance test for diagnosing adult GH deficiency.","references":[{"citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","where":"Eur J Endocrinol, 2002;146:667–672","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}],"verbatim":{"text":"The results suggest that testing with GHRP-6 or GHRP-6+GHRH is as sensitive and specific as an ITT for the diagnosis of adult GH deficiency.","citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}},{"outcome":"Appetite","grade":"C","grade_meaning":"weak human evidence","effect_size":"small","adverse":false,"human_studies":"Small human studies","evidence":"As a ghrelin-receptor agonist it increases hunger; the human appetite data are smaller and less quantified than for GHRP-2.","references":[{"citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","where":"Eur J Endocrinol, 2002;146:667–672","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}]},{"outcome":"Body composition","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":false,"human_studies":"None","evidence":"No controlled trial has tested whether repeated GHRP-6 changes muscle or fat in people.","references":[{"citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","where":"Eur J Endocrinol, 2002;146:667–672","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}]},{"outcome":"Safety in humans","grade":"C","grade_meaning":"weak human evidence","effect_size":"small","adverse":true,"human_studies":"Diagnostic use","evidence":"As a single diagnostic dose, flushing was the only side effect reported. Repeated-use safety is not established.","references":[{"citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","where":"Eur J Endocrinol, 2002;146:667–672","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}],"verbatim":{"text":"During administration of GHRP-6, the only side effects observed were flush symptoms.","citation":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/"}}],"regions":[{"region":"European Union","status":"Unauthorised medicinal product","note":"No marketing authorisation in any member state. Supplying it for human use is an offence under national medicines law; a 'research use only' label does not change that."},{"region":"United States","status":"Not approved","note":"Not an approved drug and not a dietary-supplement ingredient. Sold as a 'research chemical' outside the medical system; the FDA has warned against several compounds in this class."},{"region":"United Kingdom","status":"Unlicensed medicine","note":"Not licensed by the MHRA. Selling or supplying it for human use is an offence under the Human Medicines Regulations 2012."},{"region":"Australia","status":"Prescription-only / unapproved","note":"Not on the ARTG. Supply without a prescription is unlawful; imports are seized."},{"region":"Canada","status":"Not authorised","note":"No Drug Identification Number; selling it for human use is illegal."},{"region":"Sport (WADA)","status":"Prohibited at all times","note":"WADA class S2.2: growth-hormone secretagogues and GH-releasing peptides are banned in and out of competition."}],"faq":[{"q":"What is GHRP-6 actually good for?","a":"As a diagnostic stimulus for growth-hormone deficiency it performs as well as the standard insulin tolerance test. That is its only evidence-backed use."},{"q":"Does it build muscle?","a":"No controlled human trial has tested it. Like the rest of the class, it raises growth hormone acutely but has no outcome data for body composition."},{"q":"How is it different from GHRP-2?","a":"They are close cousins. GHRP-2 has a formal diagnostic approval in Japan and better-quantified appetite data; GHRP-6 is the older molecule and drives hunger somewhat more prominently."}],"references":[{"cite":"Petersenn S, et al. Diagnosis of growth hormone deficiency in adults by testing with GHRP-6 alone or with GHRH: comparison with the insulin tolerance test.","where":"Eur J Endocrinol, 2002;146:667–672","url":"https://pubmed.ncbi.nlm.nih.gov/11980622/","note":"20 patients; diagnostic performance equal to the ITT."}],"last_reviewed":"2026-09-03","literature_searched_to":"2026-09-03","changelog":[{"date":"2026-09-03","note":"Initial publication. Grade reflects diagnostic-grade GH data and no outcome trials."}],"license":"CC BY 4.0 — cite as “LYO Research” with a link.","methodology":"https://lyoresearch.com/methodology"}