Speaker
Description
Oral contraceptive pills remain widely used for both birth control and the management of reproductive disorders. However, side effects such as thrombosis and myocardial infarction continue to raise concerns, even with current formulations. While formulation improvements persist, alignment of drug administration with circadian rhythms -- proven to enhance safety and efficacy in other drug classes - remains underexplored in reproductive health. To address this gap, we developed a mathematical model of hormonal contraception incorporating circadian rhythms of key reproductive hormones ($\textrm {LH}$, $\textrm {FSH}$, $\textrm E_2$, and $\textrm P_4$). A drug pharmacokinetic component was added to simulate how dosing time affects contraceptive action. Simulations revealed that contraceptive efficacy varies with timing of intake, with daytime dosing consistently providing stronger suppression of ovulatory signals compared to evening dosing. This effect arises from alignment between the drug’s concentration peak and the $\textrm {LH}$ production peak. These findings offer a mechanistic basis for time-of-day–specific contraceptive recommendations, which may enhance both the safety and efficacy of hormonal contraception.
