Evra virker ligesom p- pillen, idet det ændrer kroppens hormonbalance for at hindre ægløsning, det ændrer cervixslimhinden og gør livmoderslimhinden tyndere.
Evra works like the pill by changing the body ’ s hormonal balance to prevent ovulation, by altering the cervical mucus and by thinning the endometrium (the lining of the womb).