IC50) er 0, 16 (± 0, 05) µM, hvorimod IC50 for COX- 1 er 56 (± 7) µM.
The concentration of firocoxib required to inhibit 50% of the COX-2 enzyme (i. e., the IC50) is 0.16 (± 0.05) µM, whereas the IC50 for COX-1 is 56 (± 7) µM.