Question: is nadh the reduced form?
Answer: NAD can exist in two forms: NAD+ and NADH. These two forms of NAD are known as a "redox couple," a term that is used to describe a reduced (the "red" in redox) and oxidized (the "ox" in redox) form of the same atom or molecule. ... For example, NADH can't do what NAD+ does, and vice versa.