Rat CGRP-(8-37) (VTHRLAGLLSRSGGVVKDNFVPTNVGSEAF) is a highly selective CGRP receptor antagonist. IC50 & Target: CGRP receptor^[1] In Vitro: CGRP-(8-37) is a truncated version of calcitonin gene-related peptide (CGRP) that binds to the CGRP receptor with similar affinity but does not activate the receptor^[1]. In Vivo: CGRP-(8-37) is effective in alleviating mechanical and thermal allodynia in a dose-dependent manner. The 50 nM dose is most efficacious for both forelimb and hindlimb responses. The period of efficacy is 10 min to onset for a duration of 20 min. Post-drug washout responses are not statistically significant compared to pre-drug responses^[1]. Intrathecal administration of 5 nmol or 10 nmol of CGRP-(8-37), but not 1 nmol, induces a significant increase in hindpaw withdrawal latency. Intrathecal administration of CGRP-(8-37) not only reverses the SP-induced decrease in latency to both withdrawal responses but also mediates a significant increase in response latency compared to basal levels^[2].