Head-to-Head Comparison of GHRP-2 and Hexarelin for Growth Hormone Release in Humans
GHRP-2 and hexarelin both potently stimulate GH release in humans with slight effects on prolactin, ACTH, and cortisol — their first direct head-to-head comparison.
Quick Facts
What This Study Found
GHRP-2 and hexarelin both showed potent GH-releasing activity with slight stimulatory effects on prolactin, ACTH, and cortisol; their GH-releasing activities were directly compared for the first time.
Key Numbers
How They Did This
Randomized clinical trial comparing GHRP-2, hexarelin, GHRH, TRH, and CRH administration in healthy men, measuring GH, prolactin, ACTH, and cortisol responses.
Why This Research Matters
This head-to-head comparison helps clinicians and researchers choose between the two most popular GHRPs and understand their hormonal side effect profiles.
The Bigger Picture
This comparative study helped establish the relative positioning of different GHRPs and inform clinical decision-making about which secretagogue to use.
What This Study Doesn't Tell Us
Acute single-dose study in healthy men only. No women included. Long-term effects and functional outcomes not assessed.
Questions This Raises
- ?Which GHRP has the best GH-specificity with fewest off-target hormonal effects?
- ?Do the prolactin and cortisol effects of GHRPs diminish with chronic use?
Trust & Context
- Key Stat:
- First head-to-head comparison GHRP-2 and hexarelin were directly compared for the first time in humans for GH and multiple other hormone effects
- Evidence Grade:
- Strong evidence from a randomized clinical trial with multiple comparators. Comprehensive hormonal profiling provides clinically useful data.
- Study Age:
- Published in 1997, this remains a key reference for comparing GHRP-2 and hexarelin hormonal profiles.
- Original Title:
- Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Comparison with the effects of GHRH, TRH and hCRH.
- Published In:
- Peptides, 18(6), 885-91 (1997)
- Authors:
- Arvat, E(6), di Vito, L, Maccagno, B, Broglio, F, Boghen, M F, Deghenghi, R, Camanni, F, Ghigo, E
- Database ID:
- RPEP-00397
Evidence Hierarchy
Frequently Asked Questions
Which is better — GHRP-2 or hexarelin?
Both are potent GH releasers. This study provided their first direct comparison. GHRP-2 tends to be slightly more potent based on other studies, but both have similar hormonal profiles with slight prolactin and cortisol stimulation alongside GH release.
Why do GHRPs also affect prolactin and cortisol?
GHRP receptors are not exclusively on GH-producing cells. They're also present on cells that produce prolactin and ACTH (which drives cortisol). The effects on these hormones are typically mild compared to the GH response, but they're important to monitor.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00397APA
Arvat, E; di Vito, L; Maccagno, B; Broglio, F; Boghen, M F; Deghenghi, R; Camanni, F; Ghigo, E. (1997). Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Comparison with the effects of GHRH, TRH and hCRH.. Peptides, 18(6), 885-91.
MLA
Arvat, E, et al. "Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Comparison with the effects of GHRH, TRH and hCRH.." Peptides, 1997.
RethinkPeptides
RethinkPeptides Research Database. "Effects of GHRP-2 and hexarelin, two synthetic GH-releasing ..." RPEP-00397. Retrieved from https://rethinkpeptides.com/research/arvat-1997-effects-of-ghrp2-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.