Menstrual Bleeding and Bioidentical Hormones

Do Women Need to Bleed on Bioidentical Hormone Therapy?

Confusion about whether menopausal women should “cycle” their hormones has grown in recent years, especially as celebrities promote differing approaches to bioidentical hormone therapy (BHRT). Some claim that monthly bleeding is “natural” and should continue indefinitely. However, modern endocrine research does not support this practice.

Current evidence and clinical guidelines confirm that menopausal women do not need to menstruate—and stopping progesterone monthly (to induce bleeding) may reduce important protective benefits of continuous therapy.

What Is “Cycling” Hormone Therapy?

Cycling occurs when progesterone is intentionally stopped for several days each month to induce menstrual bleeding. This mimics the premenopausal monthly hormone withdrawal that triggers a period.

However, cycling is not necessary in menopause, and in many cases, it can undermine comfort, safety, and continuity of treatment.

Why Menopausal Women Do NOT Need to Menstruate

1. Hormone therapy does not replicate pregnancy

Estrogen levels in pregnancy reach extremely high levels. In contrast, BHRT restores estradiol to physiologic ranges typical of early reproductive years—not pregnancy (Faubion et al., 2015)¹.

2. Menstruation exists to prepare for pregnancy

Menstrual bleeding clears the uterine lining to prepare for possible embryo implantation. Once fertility is no longer a goal, this physiologic cycle has no purpose (The North American Menopause Society, 2022)².

3. Bleeding is the #1 reason women stop HRT

Unexpected bleeding is the leading cause of discontinuation of hormone therapy (Davis et al., 2018)³. Most women welcome the end of monthly bleeding and prefer continuous regimens.

4. Continuous progesterone prevents postmenopausal bleeding

When estrogen and progesterone are properly balanced, bleeding should not occur. Continuous progesterone stabilizes the endometrial lining and improves treatment satisfaction (Stuenkel et al., 2015)⁴.

Why Continuous Progesterone Is Safer Than Cycling

1. Progesterone protects against endometrial cancer

Continuous progesterone provides consistent protection of the uterine lining. Stopping progesterone for several days removes this protective effect and can increase the risk of endometrial hyperplasia (Mueller et al., 2021)⁵.

2. Bioidentical progesterone does NOT stimulate breast tissue

Unlike synthetic progestins, micronized bioidentical progesterone:

• Does not increase breast tissue proliferation

• Downregulates estrogen receptors

• Has not been associated with increased breast cancer risk
  (Stute et al., 2018; Fournier et al., 2018)⁶⁷

3. Synthetic progestins (e.g., medroxyprogesterone) are the real concern

Synthetic progestins have been shown to:

• Increase breast density

• Stimulate breast receptors

• Increase breast cancer risk
  (Fournier et al., 2018)⁷

Bioidentical progesterone has opposite effects and is considered safer for long-term use.

Endometrial Hyperplasia Requires Progesterone—Not Bleeding

Endometrial hyperplasia (thickening of the uterine lining) is a precursor to uterine cancer.
The medical treatment is therapeutic doses of progesterone, not inducing menstruation (Mueller et al., 2021)⁵.

When progesterone is inadequate, the lining may thicken. Raising progesterone—not cycling—is the evidence-based treatment.

Continuous BHRT Is Well-Supported by Modern Research

Continuous estrogen + progesterone therapy:

• Stabilizes hormone levels

• Prevents withdrawal bleeding

• Reduces PMS-like symptoms

• Protects the uterus

• Does not increase breast cancer risk when using bioidentical progesterone
  (Stute et al., 2019; The North American Menopause Society, 2022)¹²

There is no evidence-based medical benefit to monthly bleeding in menopausal women.

Conclusion

Modern endocrine research confirms:

• Menopausal women do not need to menstruate.

• Cycling progesterone offers no health benefit.

• Continuous progesterone provides uterine protection and greater comfort.

• Bioidentical progesterone is safer than synthetic progestins and does not stimulate breast tissue.

Women should feel confident using continuous BHRT without fear of needing to bleed to be “normal.” Guided by a qualified hormone specialist, continuous therapy is both safe and physiologically appropriate.

References (APA 7th Edition, 2010–2026)

1. Faubion, S. S., Kuhle, C. L., Shuster, L. T., & Rocca, W. A. (2015). Long-term health consequences of premature or early menopause and considerations for management. Climacteric, 18(4), 483–491.

2. The North American Menopause Society. (2022). The 2022 hormone therapy position statement of The North American Menopause Society. Menopause, 29(7), 767–794.

3. Davis, S. R., Lambrinoudaki, I., Lumsden, M., Mishra, G. D., Pal, L., Rees, M., & Santoro, N. (2018). Menopause. Nature Reviews Disease Primers, 4(1), 18039.

4. Stuenkel, C. A., et al. (2015). Treatment of the symptoms of menopause: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism, 100(11), 3975–4011.

5. Mueller, M., et al. (2021). Management of endometrial hyperplasia. Lancet Oncology, 22(5), e192–e202.

6. Stute, P., et al. (2018). The impact of micronized progesterone on breast cancer risk: A systematic review. Climacteric, 21(2), 111–122.

7. Fournier, A., Dossus, L., & Mesrine, S. (2018). Estrogen-progestogen menopausal hormone therapy and breast cancer: Does the type of progestogen matter? Maturitas, 115, 1–8.