In enzymology, indole-3-acetaldehyde reductase (NADPH) () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are [tryptophol and oxidised nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>). Its products are indole-3-acetaldehyde, reduced NADPH, and a proton.
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 (indol-3-yl)ethanol:NADP<sup>+</sup> oxidoreductase. Other names in common use include indoleacetaldehyde (reduced nicotinamide adenine dinucleotide, phosphate) reductase, indole-3-acetaldehyde reductase (NADPH), and indole-3-ethanol:NADP<sup>+</sup> oxidoreductase. This enzyme participates in tryptophan metabolism.