Method for measuring the presence of a compound or a physiological parameter in the human or animal body, comprising positioning an intravaginal ring that comprises a sensor for the compound or parameter to be measured in contact with the vaginal mucosa and recording a signal produced by the sensor. It is further disclosed a method for the combined administration and measurement of compounds in the human or animal body, comprising the administration of one or more biologically active compounds and the simultaneous and/or subsequent measurement of the presence and/or concentration of the same and/or another compound and/or physiological parameter that is the result of the administration of the one or more biologically active compounds, wherein the measurement is performed with a sensor that is in contact with the vaginal mucosa.