Presence of endogenous prednisolone in human urine

► Prednisolone endogenous presence in bovine and horse urine has already been shown. ► A study on the presence of prednisolone in human urine was carried out. ► It was always detected in 34 untreated volunteers at concentrations lower than 1 ng/mL. ► In one volunteer urine, prednisolone was suppressed by betamethasone administration. ► The prednisolone to cortisol ratio was always roughly 1/100.