Norfluoxetine is an active metabolite of the antidepressant fluoxetine that inhibits serotonin uptake with a pKi value of 7.35. The S-enantiomer of norfluoxetine has 20-times higher serotonin reuptake blocking potency than the R-enantiomer (pKis = 7.86 versus 6.51, respectively).
