Phenylethylidenehydrazine

Phenylethylidenehydrazine (PEH), also known as 2-phenylethylhydrazone or β-phenylethylidenehydrazine, is a GABA transaminase inhibitor. It is a metabolite of the antidepressant phenelzine and is responsible for its elevation of GABA concentrations. PEH may contribute to phenelzine's anxiolytic effects.