LSD1-IN-34 (Compound 7d) is the orally active inhibitor for Lysine-specific demethylase (LSD) and monoamine oxidase (MAO) , with IC 50 of 4.51 and 18.46 nM, for LSD1 and MAO A. LSD1-IN-34 inhibits the Ang II-induced neonatal rat myocardial fibroblasts (NRCFs) activation, without significant toxicity (20 μM). LSD1-IN-34 inhibits TGFβ/Smad signaling pathway, and ameliorates heart failure in mice. LSD1-IN-34 exhibits good pharmacokinetic characteristics in rats.