What is a common side effect of combined oral contraceptives?

Nausea and breast tenderness are well-documented side effects associated with the use of combined oral contraceptives (COCs). The hormonal components of COCs (estrogen and progestin) can lead to changes in the body's physiological state, which can manifest as nausea, particularly when starting the medication or adjusting doses. Breast tenderness occurs due to hormonal fluctuations and the effect of estrogen on breast tissue, leading to edema and sensitivity.

While other side effects are possible, nausea and breast tenderness are among the most frequently reported by users of combined oral contraceptives, especially during the initial months of use. Monitoring and management of these side effects are important in clinical practice as they can affect adherence to the contraceptive regimen.