Growth hormone-releasing effect of oral growth hormone-releasing peptide 6 (GHRP-6) administration in children with short stature

This study investigated the efficacy of oral GHRP-6 administration in stimulating growth hormone secretion in 13 children with short stature. The research was motivated by the search for non-invasive alternatives to recombinant GH injections, particularly relevant for pediatric patients where adherence to injectable treatment can be problematic.

The researchers administered GHRP-6 orally at a dose of 300 µg/kg and compared the GH response with that obtained after intravenous administration of GHRH (growth hormone-releasing hormone) at the maximum effective dose of 1 µg/kg. The results demonstrated that oral GHRP-6 produced GH secretion elevation comparable to intravenous GHRH, with clinically significant GH peaks.

A notable aspect of this study is the demonstration of oral bioavailability of GHRP-6, since peptides generally undergo enzymatic degradation in the gastrointestinal tract. The efficacy via the oral route suggests that GHRP-6 absorption is sufficient to achieve therapeutic plasma concentrations, possibly due to its hexapeptide structure being relatively resistant to proteolysis.

The authors concluded that oral GHRP-6 represents a promising diagnostic and potentially therapeutic tool for children with GH deficiency, offering the convenience of oral administration with efficacy comparable to parenteral routes. This study was one of the first to validate the oral route for GH secretagogues in a pediatric population.