Hexarelin
Hexarelin, a peptide. Most potent GHSR-1a agonist among the GHRPs (2-MeTrp substitution drives receptor affinity). Also binds CD36 —… Subcutaneous half-life 1.3 h.
Most potent GHSR-1a agonist among the GHRPs (2-MeTrp substitution drives receptor affinity). Also binds CD36 — distinct from pure GHSR action — explaining reported cardioprotective preclinical effects. Rapidly desensitises the receptor with daily use.
PK is RAT and labelled as such. Roumi 2000 (PMID:10611139), male Sprague-Dawley rats, IV and SC, verbatim "a half-life of 75.9 +/- 9.3 min" (1.27 h) and "Hexarelin bioavailability given s.c. was 64%" — a true plasma bioavailability, and both values come from one study so they stay mutually consistent. The human figure previously stored, 0.77 from Ghigo 1994 (PMID:8126144), is a BIOLOGICAL bioavailability derived from growth-hormone release, a pharmacodynamic ratio rather than a plasma measurement, and is not interchangeable with a PK F. The stored half-life of 0.6 h matched no species: rat is 75.9 min, dog 120 min (PMID:8545255). V 14 L and ka 2 /h dropped — the rat volume is 744 mL/kg, roughly 52 L at 70 kg, and no absorption constant is published in any species.
Pharmacokinetics
- Subcutaneous — t½ 1.3 h · F 64%
Sources: PMID:8126144, PMID:10611139