K 41498 is a selective peptide antagonist targeting both corticotropin-releasing factor receptor 2α (CRF2α) and CRF2β, demonstrating high affinity with Kis of 0.66 and 0.62 nM, respectively, in HEK293 cells expressing these human receptors. Its selectivity is evident as it exhibits a significantly reduced affinity for CRF1 receptor (Ki = 425 nM in HEK293 cells expressing the human CRF1 receptor). Additionally, K 41498, when administered intravenously at 1.84 µg/animal, effectively mitigates urocortin-induced hypotension in rats. Furthermore, its intrathecal delivery ranging from 0.075 to 0.5 µmol/animal significantly lowers the mechanical paw withdrawal threshold in a rat model, indicating its potential utility in managing nociception triggered by complete Freund's adjuvant.