21-hydroxyprogesterone + oxidized [NADPH--hemoprotein reductase] + H2O + H(+) => progesterone + reduced [NADPH--hemoprotein reductase] + O2
21-hydroxyprogesterone + oxidized [nadph--hemoprotein reductase] + h2o + h(+) => progesterone + reduced [nadph--hemoprotein reductase] + o2