What it is
GHRP-6 is a synthetic hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2, described by Bowers and colleagues in 1984 as a peptide that acts on the pituitary to release growth hormone. It became a widely used research tool in human growth hormone physiology and, later, ghrelin receptor biology. It is not an approved medicine; Cuban groups have tested it in combination with epidermal growth factor in acute stroke trials.
How it works
GHRP-6 is an agonist at the ghrelin receptor GHS-R1a, and in healthy men most of its growth hormone response depended on endogenous GHRH. Animal studies also propose antioxidant, cytoprotective effects in ischaemic heart tissue.
Regulatory status
- Cosmetic ingredient
- Research compound
- In clinical trials
- Approved medicine
Not approved as a medicine by the FDA or the EMA. Some are registered in individual countries. Supplied for laboratory research only.
What published research is studying
- Growth hormone release and its dependence on endogenous GHRH in healthy adults
- Combined GHRH plus GHRP-6 testing for adult growth hormone deficiency
- Acute ischaemic stroke, in combination with epidermal growth factor (Phase 1/2 and Phase 3 trials)
- Myocardial infarct size in a pig coronary occlusion model (preclinical)
Key findings
In 9 healthy young men, pretreatment with a GHRH receptor antagonist cut the peak growth hormone rise after intravenous GHRP-6 from 33.8 to 6.2 micrograms per litre.
Pandya N et al., J Clin Endocrinol Metab 1998In a multicentre study of 125 adults with organic pituitary disease and 125 healthy controls, combined GHRH plus GHRP-6 produced a mean growth hormone peak of 59.2 micrograms per litre in controls versus 4.1 in patients, with 15.0 micrograms per litre as the cut-off.
Popovic V et al., Lancet 2000In 9 healthy male volunteers given single intravenous doses at three levels, GHRP-6 showed a distribution half-life of 7.6 minutes and an elimination half-life of 2.5 hours, with a trend toward dose-proportional exposure.
Cabrales A et al., Eur J Pharm Sci 2013In an open-label Phase 3 trial in 188 patients with acute ischaemic stroke, 7 days of intravenous epidermal growth factor plus GHRP-6 added to standard care missed its primary endpoint, with no intention-to-treat difference in modified Rankin Scale, Barthel Index or survival.
Hernández-Bernal F et al., J Clin Neurosci 2026In anaesthetised pigs given 1 hour of coronary occlusion and 72 hours of reperfusion, GHRP-6 reduced infarct mass by 78% and infarct thickness by 50% compared with saline.
Berlanga J et al., Clin Sci (Lond) 2007
What the studies measured
Study durations
- Phase 3 stroke trial: epidermal growth factor plus GHRP-6 twice daily for 7 days, with outcomes at 3 and 6 months (Hernández-Bernal et al. 2026).
- Phase 1/2 stroke trial: 7 days of twice-daily dosing, with safety followed over 6 months (Hernández-Bernal et al. 2024).
- Pig myocardial infarction model: 1 hour of coronary occlusion followed by 72 hours of reperfusion (Berlanga et al. 2007).
- Rat weight gain studies: once or twice daily dosing for 9 or 25 days (Bowers et al. 1984).
Endpoints
- Peak growth hormone increase and area under the growth hormone curve
- Diagnostic cut-off against the insulin tolerance test
- Distribution and elimination half-life
- Modified Rankin Scale, Barthel Index and survival after stroke
- Infarct mass, CK-MB and oxidative stress markers
How strong is the evidence?
Human data on GHRP-6 alone are limited to acute hormone, diagnostic and pharmacokinetic studies; its only Phase 3 trial tested it with epidermal growth factor and missed its primary endpoint, and the cytoprotection findings come from animals.
Common questions
Is GHRP-6 an approved medicine?
Research compound. Not approved as a medicine by the FDA or the EMA. Some are registered in individual countries. Supplied for laboratory research only.
How much human research is there on GHRP-6?
Human data on GHRP-6 alone are limited to acute hormone, diagnostic and pharmacokinetic studies; its only Phase 3 trial tested it with epidermal growth factor and missed its primary endpoint, and the cytoprotection findings come from animals.
Does UU supply GHRP-6?
Yes, as premium-grade research material for laboratory use. Every batch is tested by an independent lab and the certificate of analysis is published.