Sermorelin
Sermorelin, a peptide. Truncated 29-residue N-terminal fragment of native GHRH — retains full GH-releasing activity. Binds GHRH-R on… Subcutaneous half-life 0.1 h.
Truncated 29-residue N-terminal fragment of native GHRH — retains full GH-releasing activity. Binds GHRH-R on somatotrophs → cAMP rise → GH release. Preserves physiologic negative-feedback loop (unlike direct HGH injection) so overtreatment risk is lower. Very short plasma t½ (~11 min) — divided or evening dosing.
PK: Soule 1994 (PMID:7962295), 10 normal men, verbatim "that of GHRH-(1-29)-NH2 was 4.3 +/- 1.4 min" = 0.07 h. ROUTE CAVEAT: that study used constant IV infusion, not subcutaneous dosing. ka 3 /h and V 7 L dropped 2026-09-06, confirming a finding first logged in July: both were unsourced estimates, and V 7 L is refuted by the paper's own arithmetic — its metabolic clearance rate of 39.7 mL/kg/min with a 4.3 min half-life implies roughly 17 L, the same order as the Geref label's ~24 L. The only subcutaneous data for this peptide are RAT (PMID:2866222, SC bioavailability ~4%).
Pharmacokinetics
- Subcutaneous — t½ 4 min
Related compounds
- Ipamorelin — synergistic
Sources: PMID:7962295