Why should dutasteride tablets be taken for a full 20 days?

Under normal circumstances, taking dydrogesterone tablets for a full 20 days is primarily intended to simulate the physiological hormonal cycle, ensure optimal drug efficacy, maintain endometrial stability, reduce the risk of abnormal bleeding after discontinuation, and meet specific therapeutic requirements. The exact regimen should be followed according to medical advice based on the treatment goal. Detailed explanations are as follows:

1. Simulating the Physiological Hormonal Cycle: The female luteal phase typically lasts 14–16 days. In cases of menstrual disorders or assisted reproductive treatments, taking dydrogesterone for 20 days fully mimics luteal function, allowing the endometrium to undergo adequate secretory transformation. This ensures regular menstruation or provides a suitable environment for embryo implantation.

2. Ensuring Full Drug Efficacy: Dydrogesterone needs to reach a certain concentration in the body and be maintained for sufficient time to effectively regulate hormone levels. A 20-day treatment course allows the drug to fully act on target organs, achieving optimal therapeutic outcomes whether used for treating dysmenorrhea, endometriosis, or supporting assisted reproduction.

3. Maintaining Endometrial Stability: For patients with threatened miscarriage or luteal phase deficiency, continuous administration over 20 days helps stabilize the endometrial condition and reduce uterine contractions, thereby providing stable support for embryonic development. Short-term use cannot establish sustained hormonal protection and may increase the risks of miscarriage or bleeding.

4. Reducing Risk of Abnormal Bleeding After Discontinuation: After consistently taking the medication for 20 days, the body's hormone levels naturally decline upon stopping, prompting synchronized shedding of the endometrium and resulting in normal menstruation. If the full course is not completed, asynchronous endometrial shedding may occur, leading to abnormal bleeding such as heavy flow or prolonged duration.

5. Meeting Specific Therapeutic Needs: In assisted reproductive technologies such as in vitro fertilization (IVF), dydrogesterone must be used in conjunction with ovulation-inducing drugs. A 20-day dosing cycle can be synchronized with the ovulation stimulation cycle, laying the foundation for hormonal support after embryo transfer and ensuring that the hormonal environment meets the demands of pregnancy.

During treatment, the medication should be taken at a fixed time each day to avoid missed doses that could cause hormonal fluctuations. A light and nutritious diet is recommended, avoiding spicy or irritating foods. Additionally, changes in the menstrual cycle or signs of pregnancy should be monitored, and hormone levels should be regularly checked as directed by a physician.