Hi, Duphaston is a medication that contains dydrogesterone, a synthetic hormone that is similar to the hormone progesterone. While vaginal dryness is not a common side effect of Duphaston, your body s response to the medication may be causing changes in hormone levels that are leading to vaginal dryness. Vaginal dryness can also be a symptom of PCOS, as the condition can cause hormonal imbalances that affect vaginal lubrication. Additionally, stress and anxiety can also contribute to vaginal dryness. It is recommended to speak with a healthcare provider or gynecologist to determine the underlying cause of your symptoms and appropriate treatment options. In the meantime, using a water-based lubricant during sexual activity and practicing relaxation techniques may help alleviate symptoms of vaginal dryness. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician