Table 3.

Characteristics of kisspeptin receptor antagonists

Kisspeptin receptor antagonists	Sequence	Affinity	Half-life (t½)	Potency (in vivo and in vitro)	BBB permeability	Related studies
P234	(D-Ala)-Asn-Trp-Asn-Gly-Phe-Gly-(D-Trp)-Arg-Phe-NH2	Reference	Unclear	90% inhibition of KP10 activated signalings	Unclear	(Roseweir et al. 2009 [9]; Pineda et al. 2010 [70]; Albers-Wolthers et al. 2017 [106])
P271	Arg-Arg-Met-Lys-Trp-Lys-Lys-Tyr-(D-Ala)-Asn-Trp-Asn-Gly-Phe-Gly-(D-Trp)-Arg-Phe-NH2	Comparable with P234	Unclear	Comparable with P234	Probably Yes	(Pineda et al. 2010 [70]; Smith et al. 2011 [107]; Albers-Wolthers et al. 2017 [106])
Compound 15a	2-Acylamino-4,6-diphenylpyridine	Comparable with P234	Unclear	Lower than P234	Probably Yes	(Kobayashi et al. 2010 [108, 109])