Non-Peptide GH Secretagogue Maintains Effectiveness Over 15 Days of Daily Dosing in Dogs
L-692,585 produced 4-7 fold GH increases in dogs with maintained efficacy over 15 days of daily dosing and significantly elevated IGF-1 by day 15.
Quick Facts
What This Study Found
L-692,585 produced 4.3 to 7-fold increases in peak GH with maintained efficacy over 15 days of daily dosing and elevated IGF-1 by day 15.
Key Numbers
How They Did This
Eight beagle dogs received single IV doses of L-692,585 at three dose levels or saline in a balanced study. A separate group received daily doses for 15 days with GH, IGF-1, ACTH, cortisol, prolactin, insulin, and thyroxine measured.
Why This Research Matters
Non-peptide GH secretagogues can be taken by mouth, unlike peptide versions that need injection. This study showed L-692,585 maintains its effect with repeated dosing, a key requirement for practical clinical use.
The Bigger Picture
For a GH secretagogue to work clinically, it must not lose effectiveness with repeated dosing. This study proved that a non-peptide GH-releasing drug can sustain its effects over time — a crucial milestone toward drugs like MK-677.
What This Study Doesn't Tell Us
Animal study in dogs. Beagle GH physiology differs from humans. Only 15 days of repeated dosing was tested. Intravenous route used rather than oral.
Questions This Raises
- ?Does efficacy persist beyond 15 days?
- ?Would oral bioavailability allow practical human use?
Trust & Context
- Key Stat:
- 15 days, no tolerance Daily L-692,585 dosing maintained GH release and raised IGF-1 — no desensitization over 15 days
- Evidence Grade:
- Moderate — animal study in dogs with repeated-dose design. 8-dog balanced study with multiple endpoints.
- Study Age:
- Published in 1994 (32 years ago). This work contributed to MK-677 development, which has longer-term human data.
- Original Title:
- Effects of acute and repeated intravenous administration of L-692,585, a novel non-peptidyl growth hormone secretagogue, on plasma growth hormone, IGF-1, ACTH, cortisol, prolactin, insulin, and thyroxine levels in beagles.
- Published In:
- The Journal of endocrinology, 143(2), 399-406 (1994)
- Authors:
- Jacks, T(3), Hickey, G(4), Judith, F, Taylor, J, Chen, H, Krupa, D, Feeney, W, Schoen, W, Ok, D, Fisher, M
- Database ID:
- RPEP-00295
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Why does maintaining effectiveness matter?
Many drugs lose their effect with repeated use (tolerance). For a GH secretagogue to be clinically useful, it must keep working day after day. This study showed L-692,585 does — a key milestone.
What is IGF-1 and why did it rise?
IGF-1 (insulin-like growth factor 1) is the downstream hormone that carries out many of GH's effects on growth, muscle, and metabolism. Its rise by day 15 proves the GH release is biologically meaningful.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00295APA
Jacks, T; Hickey, G; Judith, F; Taylor, J; Chen, H; Krupa, D; Feeney, W; Schoen, W; Ok, D; Fisher, M. (1994). Effects of acute and repeated intravenous administration of L-692,585, a novel non-peptidyl growth hormone secretagogue, on plasma growth hormone, IGF-1, ACTH, cortisol, prolactin, insulin, and thyroxine levels in beagles.. The Journal of endocrinology, 143(2), 399-406.
MLA
Jacks, T, et al. "Effects of acute and repeated intravenous administration of L-692,585, a novel non-peptidyl growth hormone secretagogue, on plasma growth hormone, IGF-1, ACTH, cortisol, prolactin, insulin, and thyroxine levels in beagles.." The Journal of endocrinology, 1994.
RethinkPeptides
RethinkPeptides Research Database. "Effects of acute and repeated intravenous administration of ..." RPEP-00295. Retrieved from https://rethinkpeptides.com/research/jacks-1994-effects-of-acute-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.