Side effects vary by formulation. Willow can cause hormonal changes including changes in libido, breast tenderness, upset stomach, menstrual changes, or signs of fluid or electrolyte imbalance such as mood changes, muscle cramps, or tiredness. Ivy can cause hormonal changes, changes in libido, breast tenderness, upset stomach or nausea, and possible mood changes. Either can cause signs of an allergic reaction (rash, hives, itching, swelling, difficulty breathing), which need medical attention right away. Your provider screens for factors like significant heart conditions, uncontrolled blood pressure, a history of hormone-sensitive cancer for Willow, and a history of depression for Ivy, and stays available throughout. That’s the point of provider-led care.