Study wrapper · #226
Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.
Editor's note
A rat pharmacokinetics study comparing ipamorelin with related secretagogues (GHRP-2, GHRP-6, and two NNC compounds) across routes of administration. The standout findings: ipamorelin cleared from plasma about five-fold more slowly than GHRP-6, was excreted mainly in urine (GHRP-6 mainly in bile), and resisted metabolism, with 60-80% recovered intact. After intranasal dosing, ipamorelin's bioavailability was roughly 20%, lower than some comparators (~50%) but still enough to suggest the nasal route can deliver this peptide class systemically. This is disposition and delivery characterisation, not efficacy; it tells us how the molecule moves and is eliminated, which is genuinely useful for formulation, but says nothing about clinical effect. For Ipamorelin and GHRP-6, this is preclinical pharmacokinetic groundwork in rats; human data would be required before any practical or clinical conclusions.
Plain-language abstract
This study measured how ipamorelin and several related growth-hormone-releasing peptides move through and leave the body in rats, given by different routes. After injection into a vein, blood levels of all the peptides fell in two phases. Ipamorelin stood out: the body cleared it about five times more slowly than GHRP-6. Ipamorelin left the body mainly through urine, whereas GHRP-6 left mainly through bile (via the liver and gut). Ipamorelin and two related peptides were fairly resistant to being broken down, with 60-80% recovered intact. When sprayed into the nose, about 20% of an ipamorelin dose reached the bloodstream; some of the other peptides reached higher levels (around 50%). The researchers concluded that these peptides can cross the lining of the nose reasonably well, making a nasal spray a promising delivery route for this family of compounds. This is animal research focused on how the drugs are absorbed and cleared, not on any health effect in people.