A highly potent and selective inhibitor of the type 5 17-β-hydroxysteroid dehydrogenase AKR1C3 (IC₅₀ = 94 nM). Displays much weaker inhibitory activity against AKR1C1, AKR1C2 and AKR1C4 (IC₅₀ >30 µM). Does not display any COX (cyclooxygenase) inhibition at 10 µM in whole blood assay.