REHOVOT, ISRAEL — October 12, 2026 — Menopause is commonly viewed as a gradual process that takes years, but a new study by Weizmann Institute of Science researchers, published today in Nature Medicine, reveals that the female body also undergoes a sharp transition around the time of the last menstrual period. Analyzing more than 300 million laboratory test results from over 1 million women in the United States and Israel, Prof. Uri Alon and his team identified abrupt changes in dozens of measures of bodily health and function, far beyond the familiar shifts in sex hormone levels and the loss of fertility.
“Our study extends the window for potential preventive care to almost a decade before menopause," Alon says.
The changes appeared in 52 of the 90 types of laboratory tests examined, covering nearly all body systems, including tests of bone health, liver and kidney function, and cholesterol levels. No such abrupt changes were observed in men of similar ages, and the changes were less pronounced in women receiving menopausal hormone therapy. The study also revealed that the sudden shifts were preceded by accelerating changes in sex hormone levels that began more than a decade before menopause – several years earlier than previously thought.
The research team, led by Dr. Glen Pridham and Yoav Hayut from Alon’s lab in Weizmann’s Molecular Cell Biology Department, analyzed two large sets of data: results from the US National Health and Nutrition Examination Survey, conducted over more than two decades, and medical records collected over some 20 years by Israel’s health insurer Clalit.
Such large datasets are rarely used in menopause research because they generally lack information about the age at which women had their last period. To overcome this limitation, the researchers developed a computational method inspired by astronomy. Just as astronomers can sharpen an image by mathematically correcting distortions caused by a telescope, the new method removed the “blur” in medical data caused by differences in the age at which women reach menopause.
Results of 39 laboratory tests differed between women receiving menopausal hormone therapy and those not receiving it, suggesting that the therapy may soften many of the abrupt changes associated with menopause.
Because most of the abrupt changes identified in the study are associated with increased disease risk, the findings could help women take preventive steps, such as exercising and improving their diet, years before menopause. “Our study extends the window for potential preventive care to almost a decade before menopause,” Alon says. “More broadly, the method we developed may help study other major changes in life, such as puberty, pregnancy or the onset of disease.”
Also taking part in the study were Dr. Noa Lavi-Shoseyov and Prof. Michal Neeman of Weizmann’s Immunology and Regenerative Biology Department; Dr. Noa Hovav of the Menopause Community Center, Clalit Health Care; and Dr. Yoel Toledano of the Helen Schneider Women’s Hospital, Rabin Medical Center. Dr. Lavi-Shoseyov is also affiliated with the IVF Unit, Department of Obstetrics and Gynecology, Kaplan Medical Center.