Pamoic acid is a potent agonist of GPR35 orphan receptors (EC50 = 79 nM in a β-arrestin recruitment assay). It induces GPR35 translocation from the plasma membrane to the cytoplasm with an EC50 value of 22 nM. Pamoic acid also increases ERK1/2 phosphorylation in a concentration-dependent manner in U20S cells expressing human GPR35a. In vivo, pamoic acid has antinociceptive effects with an ED50 value of 40.5 mg/kg in a mouse abdominal constriction model of visceral pain perception. Pamoate salts, of which pamoic acid is the main constituent, have been used in drug formulations to extend the duration of action.