Tafluprost acid (AFP-172), the active metabolite of Tafluprost, is a selective agonist of the prostanoid FP receptor, with Ki and IC50 of 0.4 nM and 0.53 nM, respectively, for the human prostanoid FP receptor. It also exhibits 126-fold weaker binding affinity for the prostanoid EP3 receptor, with an IC50 of 67 nM, compared to the FP receptor.