The side effects of estrogen are mainly gastrointestinal reactions, nausea, vomiting and dizziness. In addition, estrogen can cause water and sodium retention after taking estrogen, so weight gain and fatness can occur. Long-term use of estrogen can also cause facial discoloration, which is a side effect of estrogen, and irregular vaginal bleeding may occur. Progestins may also cause gastrointestinal reactions and dizziness. In addition, taking progestin can cause rough skin. Therefore, both estrogen and progestin have side effects in clinical practice, and it is recommended that the medication must be used under the guidance of a doctor.