Active ingredient: Rifampicin

Rifampicin can affect female hormones even in women who are not taking combined oral contraceptives (COCs), although the impact is generally less pronounced. As a potent inducer of liver enzymes, particularly the cytochrome P450 (CYP3A4) system, rifampicin increases the metabolism of various steroid hormones, including estrogen and progesterone. In women not using hormonal contraceptives, rifampicin may speed up the breakdown of endogenous sex hormones, potentially affecting hormonal balance. However, clinical evidence of significant effects on natural menstrual cycles is limited. The most notable impact is typically observed in women using hormonal contraceptives or hormone replacement therapy, where rifampicin reduces hormone levels, potentially leading to ovulatory cycles, irregular periods, or reduced effectiveness of these therapies.