Estrogen Therapy Linked to Higher Autoimmune Risk
A new study identifies an increased incidence of autoimmune conditions among women using estrogen-only hormone therapy.
Updated on Oct. 23, 2026 in Women’s Health
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If you use hormone therapy, does the potential risk of autoimmune issues change your treatment view?
A retrospective study of over 100,000 women reveals that estrogen-only hormone therapy is linked to a higher incidence of composite autoimmune disease compared to combined estrogen-progestogen treatment. Findings were presented at the recent Menopause Society annual meeting.
Why it matters
Understanding the potential long-term immune effects of hormone therapies is essential for women navigating menopausal care, especially given the different uses for estrogen-only versus combined treatments. These findings help clinicians better weigh therapeutic benefits against potential risks for specific patient groups.
The study tracked over 100,000 women aged 45 to 70, observing a hazard ratio of 1.076 for composite autoimmune disease in the estrogen-only group. Outcomes were assessed at least 180 days after therapy initiation using propensity score-matched cohorts of 54,692 women each.
The players
Menopause Society
This professional organization is dedicated to advancing the health and quality of life of all women during midlife and beyond through evidence-based healthcare.
The details
Researchers found significantly increased hazards for specific conditions including systemic lupus erythematosus, psoriasis, psoriatic arthritis, multiple sclerosis, and lichen sclerosis in users of estrogen-only therapy. Data was sourced from the TriNetX U.S. Collaborative Network to compare outcomes between estrogen-only therapy, typically used after hysterectomy, and estrogen-progestogen therapy, used for endometrial protection.
Timeline
October 2026: Findings presented at the Menopause Society annual meeting.
Health Landscape
This research updates the safety landscape regarding hormone therapy risks previously established by the Women's Health Initiative. It provides new granular data on autoimmune outcomes, marking a shift toward more specialized risk assessment in menopausal medicine.
Patients currently utilizing estrogen-only hormone therapy should discuss these findings with their healthcare providers to review their specific risk profile. Clinicians may use this information to better monitor for early signs of autoimmune conditions during ongoing hormonal treatment.
The takeaway
Patients should engage in regular check-ups to discuss any new or persistent symptoms that may mimic autoimmune conditions while on hormone therapy. Maintaining a detailed health history helps doctors assess whether hormone treatment adjustments are appropriate for long-term well-being.
Further reading
Learn more about the latest research and findings in Women’s Health.
Live Poll
If you use hormone therapy, does the potential risk of autoimmune issues change your treatment view?
