Fylrevy is a medicine containing estetrol, which is the subject of a European Public Assessment Report (EPAR) with an up-to-date opinion.[1][2] It is a combined hormonal contraceptive similar to other combined hormonal drugs.[1][2] The main criterion for effectiveness was the Pearl Index, which measures the number of unwanted pregnancies in 100 women per year of use.[1][2] In the first study of 1553 women aged 18-50, the Pearl index was 0.44 for women 18-35 and 0.38 for the whole group, which is considered low enough.[1][2] In a second study of 1,864 women aged 16-50, the Pearl index was higher - 2.42 for women aged 16-35 and 2.30 for the whole group.[1][2] Overall, the EMA recognized the drug as effective in preventing unwanted pregnancy.[1][2] Side effects are similar to other combined hormonal contraceptives.[1][2]