Menopause is a natural stage in a woman's life that can be associated with symptoms such as hot flashes, night sweats, sleep problems, and vaginal dryness. Menopausal hormone therapy is commonly used to relieve these symptoms. In women with an intact uterus, progesterone must be used together with estrogen to protect the lining of the uterus.

The purpose of this study is to compare two commonly used progesterone treatment methods in women receiving menopausal hormone therapy. All participants will use transdermal estradiol gel, and they will be randomly assigned to receive either oral dydrogesterone or vaginal micronized progesterone.

This prospective randomized controlled study will evaluate the effects of these treatments on endometrial thickness, menopausal symptoms, vaginal health parameters, bleeding patterns, and quality of life over a 12-month follow-up period.

The results of this study may help determine the most appropriate progesterone regimen for women undergoing menopausal hormone therapy.

Menopausal hormone therapy (MHT) is widely used for the treatment of vasomotor symptoms and genitourinary symptoms associated with menopause. In women with an intact uterus, progestogens must be administered together with estrogen therapy to prevent endometrial hyperplasia. Different progesterone formulations and routes of administration are available, including oral and vaginal preparations. However, comparative data regarding the clinical effects and endometrial safety of different progesterone regimens combined with transdermal estradiol are limited.

This prospective randomized controlled trial aims to compare two commonly used progesterone regimens in women receiving menopausal hormone therapy. All participants will receive transdermal estradiol gel and will be randomly assigned to one of two treatment groups: oral dydrogesterone or vaginal micronized progesterone. The study will follow participants for approximately 12 months.

The primary outcome of the study is endometrial thickness measured by transvaginal ultrasonography. Secondary outcomes include menopausal symptoms, quality of life assessed by validated questionnaires, vaginal health parameters such as vaginal maturation index and vaginal pH, bleeding patterns recorded in bleeding diaries, carotid intima-media thickness, and bone mineral density measurements.

The findings of this study are expected to contribute to the identification of the most appropriate progesterone regimen for women undergoing menopausal hormone therapy.

Inclusion Criteria:

• Women aged 45-60 years
• Postmenopausal status (absence of menstruation for ≥12 months)
• Intact uterus
• Presence of menopausal symptoms requiring menopausal hormone therapy
• Willingness to participate and provide written informed consent

Exclusion Criteria:

• Unexplained vaginal bleeding
• History of breast cancer or endometrial cancer
• Known hypersensitivity to study medications
• History of thromboembolic disease (e.g., deep vein thrombosis or pulmonary embolism)
• Severe liver disease
• Uncontrolled hypertension
• Any condition that, in the opinion of the investigator, makes participation inappropriate

Female

Individual participant data will not be shared due to institutional data protection policies and privacy considerations for study participants.

The study is open-label and participants will receive one of the two progesterone regimens according to randomization.