Creating the Smallest Effective Growth Hormone-Releasing Molecules
Researchers created the smallest and most potent growth hormone secretagogues reported, with molecular weight under 500, and mapped the exact 3D shape needed for activity.
Quick Facts
What This Study Found
Novel backbone-modified GH secretagogues with molecular weight under 500 were the most potent reported, with confirmed anabolic efficacy and a defined bioactive conformation.
Key Numbers
How They Did This
Researchers altered GHRP backbone structure to create new compounds. These were tested in vitro for GH release and in vivo in rodents for anabolic effects. NMR was used to determine the 3D structure of a potent cyclic analog.
Why This Research Matters
Identifying the smallest effective GH-releasing molecules means these compounds could potentially be made into pills. Understanding the exact 3D shape needed for activity guides all future GH secretagogue drug design.
The Bigger Picture
Small molecules under 500 MW can typically be taken as pills, while larger peptides need injections. This work was a critical step toward oral growth hormone secretagogues like MK-677, potentially replacing GH injections for certain conditions.
What This Study Doesn't Tell Us
Animal study in rodents. The most potent compounds may not maintain their potency in humans. Intermittent dosing was tested but long-term safety unknown.
Questions This Raises
- ?Do these small GH secretagogues maintain their potency when given orally to humans?
- ?What are the long-term safety profiles of intermittent GH stimulation versus continuous GH administration?
Trust & Context
- Key Stat:
- MW under 500 The smallest effective GH secretagogues reported, small enough for potential oral delivery
- Evidence Grade:
- Strong — comprehensive characterization including in vitro, in vivo rodent efficacy, and structural determination via NMR.
- Study Age:
- Published in 1995. This research directly contributed to the development of MK-677 and other oral GH secretagogues that followed.
- Original Title:
- Growth hormone secretagogues: characterization, efficacy, and minimal bioactive conformation.
- Published In:
- Proceedings of the National Academy of Sciences of the United States of America, 92(24), 11165-9 (1995)
- Authors:
- McDowell, R S, Elias, K A, Stanley, M S, Burdick, D J, Burnier, J P, Chan, K S, Fairbrother, W J, Hammonds, R G, Ingle, G S, Jacobsen, N E, Mortensen, D L, Rawson, T E, Won, W B, Clark, R G, Somers, T C
- Database ID:
- RPEP-00331
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Why does molecular weight matter for drug design?
Molecules under 500 MW generally follow Lipinski's Rule of Five for oral bioavailability, meaning they can potentially be taken as pills rather than requiring injections.
What are growth hormone secretagogues?
They are compounds that stimulate the body to release its own growth hormone, as opposed to injecting synthetic GH directly. This approach may produce more natural GH release patterns.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00331APA
McDowell, R S; Elias, K A; Stanley, M S; Burdick, D J; Burnier, J P; Chan, K S; Fairbrother, W J; Hammonds, R G; Ingle, G S; Jacobsen, N E; Mortensen, D L; Rawson, T E; Won, W B; Clark, R G; Somers, T C. (1995). Growth hormone secretagogues: characterization, efficacy, and minimal bioactive conformation.. Proceedings of the National Academy of Sciences of the United States of America, 92(24), 11165-9.
MLA
McDowell, R S, et al. "Growth hormone secretagogues: characterization, efficacy, and minimal bioactive conformation.." Proceedings of the National Academy of Sciences of the United States of America, 1995.
RethinkPeptides
RethinkPeptides Research Database. "Growth hormone secretagogues: characterization, efficacy, an..." RPEP-00331. Retrieved from https://rethinkpeptides.com/research/mcdowell-1995-growth-hormone-secretagogues-characterization
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.