Valproic acid-d15 is the deuterium labeled Valproic acid. Valproic acid (VPA, 2-Propylpentanoic Acid) is an HDAC inhibitor, with IC50 in the range of 0.5 and 2 mM, also inhibits HDAC1 (IC50, 400 µM), and induces proteasomal degradation of HDAC2. Valproic