How long does it take for the steroids in an ESI to start working? How long for the temporary anesthetic to wear off? L3/L4

Epidural steroids. Normally they act in about 2-3 days but may take as long as 10 days to show the effect depending on the amount of inflammation. The local anesthetic wears off in 2-4 hours depending on which was used. If you continue to have numbness after such a procedure beyond a few hours, it is a concern and should be evaluated. Please see the physician who did your procedure.