MPEP Hydrochloride is a potent, selective, noncompetitive, orally active and systemically active mGlu5 receptor antagonist, with an IC50 of 36 nM for completely inhibiting quisqualate-stimulated phosphoinositide (PI) hydrolysis. MPEP Hydrochloride has anxiolytic-or antidepressant-like effects. MPEP (Hydrochloride) is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.