Identifying Hormone Patterns — Progesterone Decline During the Menopausal Transition
Why Progesterone Matters in Midlife
The menopausal transition is a hormonally complex period marked by the gradual decline of reproductive hormones. Among the most impactful changes is the reduction in progesterone production. As ovulation becomes less frequent with age, so too does the luteal secretion of progesterone. This decline in progesterone contributes to a hormonal imbalance—often leaving estrogen unopposed—which can fuel a variety of challenging symptoms.
The Biology Behind Progesterone Decline
Two main factors contribute to declining progesterone levels during perimenopause:
Reduced Luteal Secretion: The corpus luteum, a temporary endocrine structure formed after ovulation, becomes less efficient with age, producing less progesterone even during ovulatory cycles.
Decreased Ovulation Frequency: As women progress toward menopause, the frequency of ovulation declines. Anovulatory cycles—when no egg is released—become more common, and since progesterone is primarily produced post-ovulation, levels drop accordingly.
These changes are part of the normal physiological shift that takes place during perimenopause and can result in both subtle and significant symptoms.
Charting the Decline: What Mira Data Reveals
Mira hormone monitor users across age groups have shown consistent trends in PdG (pregnanediol glucuronide, a marker of progesterone) decline. Core hormonal patterns are identified in perimenopause: estrogen may still surge, but without the follow-through of progesterone to balance it.
The Role of Anovulatory Cycles
Disruptions in the hypothalamic-pituitary-ovarian (HPO) axis are common during perimenopause. As coordination between estrogen, LH (luteinising hormone), and progesterone falters, several variations may occur:
Estradiol peaks without an LH surge
LH surges without a follow-up rise in progesterone
Extended follicular phases with delayed or absent ovulation
These patterns help explain the wide range of physical and emotional symptoms women experience during this transition.
Symptoms of Low Progesterone and Unopposed Estrogen
Low progesterone and excess estrogen create a hormonal imbalance that manifests in various ways:
Mood Instability: Women with erratic estradiol levels and low progesterone are more prone to depressive symptoms. Conversely, cycles with robust ovulation and adequate progesterone tend to support more stable moods.
Heavy Menstrual Flow: Without sufficient progesterone to counterbalance estrogen, the endometrium can thicken excessively, resulting in heavier periods.
Physical Discomfort: Fluctuating estrogen without stabilising progesterone can lead to bloating, breast tenderness, and fatigue.
Reduced Resilience: Studies show that women with low progesterone levels often report higher stress, decreased life satisfaction, and greater emotional reactivity.
Conclusion: Making Sense of Progesterone Decline
As women move through perimenopause, declining progesterone due to both diminished luteal function and decreased ovulation is a central driver of hormonal imbalance. This change often results in unopposed estrogen, triggering mood swings, heavy bleeding, and physical symptoms that can severely affect quality of life.
Mira offers a practical tool for identifying these hormone patterns in real time. Tracking PdG, LH, and E3G together provides a clear view of whether cycles are ovulatory, suboptimal, or anovulatory. These insights empower both clinicians and patients to make informed decisions about timing, symptom correlation, and potential interventions—including hormone therapy, lifestyle changes, and targeted supplementation.
Understanding your hormone patterns is the first step to regaining balance and well-being during the menopausal transition.
If you’re wondering whether your symptoms could be related to perimenopause, our guide to diagnosing the perimenopause explains the key signs, tests, and assessment approaches used in clinical practice.
Track Your Hormones with Mira—And Save 30%
Get everything you need to monitor your hormone patterns for 3 full months:
Use discount code SIRONAHEALTH at checkout to save 30%—you'll pay just £312.20 (saving £133.80 off the full price).
Book your consultation today and request a Mira Clinic invite to securely sync your hormone data with Sirona Health—so it's ready and waiting for your appointment.
-
Progesterone levels fall because ovulation becomes less frequent with age, and the corpus luteum produces less progesterone even during ovulatory cycles.
-
Unopposed estrogen occurs when estrogen levels remain relatively high without enough progesterone to balance them. This can cause heavy periods, bloating, mood changes, and increased risk of endometrial overgrowth.
-
Yes. Tools like the Mira hormone monitor can track PdG (pregnanediol glucuronide, a progesterone metabolite) alongside estrogen and LH patterns to assess ovulation and hormonal balance.
-
Progesterone has calming effects on the brain. Low levels are linked to greater stress reactivity, mood swings, and in some cases depressive symptoms.
-
Speak to a women’s health doctor. Possible interventions include lifestyle changes, targeted supplements, and hormone therapy if appropriate.
About the Author
Dr Georgina Standen is a Women’s Health GP and Medical Director of Sirona Health. She specialises in the diagnosis and treatment of menopause and broader hormonal health. Her approach blends evidence-based medicine with personalised, compassionate support to help women navigate menopause and optimise their health and wellbeing during midlife and beyond.
Sirona Health offers menopause consultations in Bath, Stroud, Cirencester, Tetbury, and surrounding areas, along with nationwide secure online appointments.