In enzymology, a codeinone reductase (NADPH) () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are codeine and NADP<sup>+</sup>, whereas its 3 products are codeinone, NADPH, and H<sup>+</sup>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is codeine:NADP<sup>+</sup> oxidoreductase. This enzyme participates in alkaloid biosynthesis i.