Nathan López Bezerra
A large new study presented at the 2025 Annual Meeting of The Menopause Society suggests that starting hormone therapy during perimenopause may offer the greatest long-term health benefits. Researchers analyzed data from more than 120 million patient records. They found that women who began estrogen therapy during perimenopause and continued it for at least ten years had about a 60% lower risk of developing breast cancer, heart attack, or stroke. This was compared to women who started hormone therapy later or never used it at all.
The study divided women into three groups. One group started estrogen therapy during perimenopause and continued for at least ten years before menopause. Another group began hormone therapy after menopause. The third group never used hormones. Researchers then tracked the occurrence of breast cancer, heart attack, and stroke over time. Women who started therapy early had lower odds of developing all three conditions. Women who began estrogen therapy after menopause showed only minimal protective effects. The study also found a slight increase in stroke risk, about 4.9% higher, for women who started therapy after menopause compared to those who never used hormones.
Estrogen plays a role in many body systems beyond reproduction. It helps keep blood vessels flexible and supports healthy cholesterol levels in the heart. In the brain, it promotes neuroplasticity and supports mood regulation. It also helps preserve bone density and muscle strength. Introducing estrogen early, before these systems decline significantly, may help preserve their function. Waiting until after menopause, when estrogen receptors have been without stimulation for years, may not deliver the same benefits and could carry more risk.
For women in their 30s or 40s who notice signs of hormonal transition, such as shorter cycles, sleep changes, or mood fluctuations, the study suggests starting a conversation with a healthcare provider sooner rather than later. Perimenopause can begin as early as the mid-to-late 30s. Tracking cycles, symptoms, and energy levels can help identify changes. Finding a provider who personalizes therapy based on symptoms, health history, and timing is recommended. Healthy lifestyle habits, including strength training, balanced nutrition, and stress management, also support long-term health alongside any hormone therapy plan.
