Menopause conversations often focus on estrogen, but progesterone plays an important role too. Though less talked about, progesterone influences many menopause symptoms and overall women’s health.
Progesterone is mainly produced in the ovaries alongside estrogen. Both hormones regulate the menstrual cycle and support pregnancy. Progesterone also affects bone health, sleep, mood, and immune response.
However, because estrogen was discovered and studied first, it has been seen as the main hormone driving menopause changes. As a result, progesterone’s effects are less understood.
Dr. Margaret Nachtigall, a reproductive endocrinologist at NYU Grossman School of Medicine, says progesterone is “a tricky hormone.” It can improve mood and thinking for some women, but for others, it may have the opposite effect.
Progesterone Before Menopause
During reproductive years, progesterone is produced after ovulation by the corpus luteum in the ovaries. Its main job is to prepare the uterus lining for a fertilized egg and prevent the lining from becoming too thick. Dr. Nachtigall explains that estrogen causes the uterine lining to grow.
Without progesterone to balance it, the lining can grow excessively, increasing the risk of pre-cancer or endometrial cancer. This is why progesterone is included in hormone therapy for menopausal women who still have their uterus.
Progesterone also acts as an immunosuppressant, helping the body avoid rejecting a growing embryo. Additionally, it influences mood. Dr. Jerilynn Prior from the University of British Columbia notes that progesterone levels rise in the second half of the menstrual cycle, which can lead to mood symptoms such as irritability and aggression, often seen in PMS.
Progesterone During Perimenopause
Hormone levels fluctuate greatly in perimenopause. Estrogen levels swing widely, while progesterone steadily drops. This imbalance causes symptoms like heavy or irregular periods, mood swings, sleep problems, hot flashes, and night sweats.
Doctors often prescribe progestogens along with estrogen to manage symptoms for women who have a uterus. Progestogens include natural, bioidentical progesterone (micronized progesterone) and synthetic forms called progestins. Progestins are found in birth control pills and come in various oral, gel, or patch forms.
Dr. Prior’s recent research found that taking 300 mg of oral micronized progesterone nightly for three months helped reduce night sweats and improve sleep in perimenopausal women without increasing depression.
However, there are no official guidelines for treating perimenopause with progesterone alone. Dr. Chrisandra Shufelt from the Mayo Clinic prefers other treatments like antidepressants for mood or a progestin IUD for heavy bleeding. She also notes non-hormonal options exist for hot flashes, including certain medications like gabapentin or low-dose SSRIs.
Progesterone and Menopause Hormone Therapy
Once menopause begins—defined as 12 months after the last period—both estrogen and progesterone levels are very low. Hormone therapy often combines estrogen with a progestogen to relieve symptoms such as hot flashes, night sweats, and vaginal dryness.
Micronized progesterone is usually the first choice because it is bioidentical. Still, responses vary widely. Some women find it calming and helpful for sleep, while others experience worsened mood and cannot tolerate it.
In such cases, doctors may turn to synthetic progestins. These do not cause the sedative effects of natural progesterone but may also avoid some mood side effects.
Progestins had a bad reputation after a type called medroxyprogesterone acetate (MPA) was linked to a small increased breast cancer risk in the Women’s Health Initiative study. However, newer progestins appear safer, and natural progesterone combined with estrogen has not shown increased breast cancer risk for up to five years of use.
Individualized Approach Is Key
Dr. Shufelt emphasizes that hormone therapy must be personalized. Each woman reacts differently to various forms of progesterone and progestins. Finding the right treatment often requires trial and error.
Ultimately, progesterone is a complex but important hormone in menopause health. It deserves more attention alongside estrogen to help women manage this life stage more comfortably and safely.
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