Progesterone

What it does during the cycle

In the first half of a menstrual cycle, estrogen thickens the uterine lining. After an egg is released, progesterone rises and makes that lining ready for a possible pregnancy. If pregnancy does not happen, progesterone drops, the lining sheds and a period starts.

Progesterone also has effects beyond the uterus. Many women notice its influence on sleep, body temperature and breast tenderness across the cycle.

What changes in perimenopause

As ovulation becomes less regular in your 40s, the cycles without ovulation produce little progesterone. Estrogen can still swing high in that phase, so the balance between the two shifts. That imbalance may contribute to heavier or irregular bleeding, and MedlinePlus lists perimenopause among the reasons a progesterone test can come back low.

Testing progesterone

A blood progesterone test is mainly used to check whether ovulation happened, to monitor fertility treatment or early pregnancy, and to investigate abnormal bleeding. Timing matters: levels depend on where you are in your cycle, so record the first day of your last period. After menopause, levels stay low, and a single test is rarely needed to guide hormone therapy.

Progesterone in hormone therapy

Estrogen taken on its own stimulates the uterine lining and raises the risk of endometrial cancer in women with a uterus. Adding a progestogen lowers that risk, which is why it is a standard part of hormone therapy for anyone who has not had a hysterectomy. In November 2025 the FDA announced it would remove several boxed warnings from menopausal hormone therapy labels but keep the endometrial cancer warning on systemic estrogen-alone products.

Oral micronized progesterone is commonly taken at bedtime because it can cause drowsiness or dizziness. Other side effects can include headache, breast tenderness and mood changes. Progesterone creams vary in how much hormone reaches the bloodstream, which matters if endometrial protection is the goal.

At HealifyMD

Progesterone capsules and cream are included in the HealifyMD hormone therapy program, which is $349 for the first month and then $99/month, confirmed at your eligibility review. The progesterone products are compounded and not FDA-approved. Your clinician discusses individual risks, including blood clots, stroke and breast cancer, and how bleeding will be monitored.

Questions to ask before starting

Ask which form of progesterone is planned, how it will be timed with your estrogen, and what bleeding pattern to expect in the first few months. Ask how your clinician will check that your uterine lining is protected and when unexpected bleeding should prompt an ultrasound or other evaluation.