(âÂÂ)-Isopiperitenone reductase () is an enzyme with systematic name (+)-cis-isopulegone:NADP<sup>+</sup> oxidoreductase that is found in peppermint. It catalyses the following chemical reaction:
The three substrates of this enzyme are (-)-isopiperitenone, reduced nicotinamide adenine dinucleotide phosphate (NADPH), and a proton. It converts them to (+)-cis-isopulegone and oxidised NADP<sup>+</sup>.