Note that hexarelin nasal spray has been estimated to result in 5% bioavailability compared to 77% with subcutaneous injections, so nasal administration would require much higher dosing [12]
These are estimates, not confirmed prices
Mem Inst Oswaldo Cruz 110, 2347
Every published in-vivo dose was given intravenously or intraperitoneally, and nobody has measured how much of a subcutaneous dose reaches circulation
Green BW, Labagnara K, Macdonald E, Feiertag N, Zhu M, Gupta K, Mohan C, Watts KL, Rai A, Small AC (2022) Evaluating the association between food insecurity and risk of nephrolithiasis: an analysis of the National health and nutrition examination survey