The years before your final period deserve more attention

Menopause can feel a long way off when you're in your late 30s or early 40s. A new study suggests that some of the hormone changes leading up to it may already be underway.

Glen Pridham, Yoav Hayut and colleagues at the Weizmann Institute of Science analyzed more than 300 million lab tests. Their study draws on records from over a million women in the US and Israel. It appeared in Nature Medicine on October 12, 2026. [1]

The researchers found hormone changes much earlier than past studies had captured. Around the last period, they also found sharp changes in tests related to bones, the liver, blood fats and more.

That makes the years before menopause worth a closer look. They may matter for your health long before your periods stop.

A longer hormonal lead-up

The finding that stands out is how early some hormones began changing. Estradiol, a form of estrogen, began falling faster about 12 years before the last period. Two other hormones also changed earlier: AMH began falling faster about 15 years before, and FSH began rising faster about 14 years before. [1]

Think about what that means in years of your life. If the last period comes at 50, those changes would fall around ages 35 to 38. That example helps make sense of the numbers. It can't tell you when your own hormones will change.

For a woman approaching 40, that's a much closer story than menopause somewhere in the distant future.

The FSH and estrogen changes appeared about seven years earlier than past research had recorded. The authors compare their findings with SWAN, a major study that followed women through menopause. Their new approach let them look further back. [1]

The years before your last period may have more going on than past research could see. That raises a useful question about when those changes start to matter for your health.

This doesn't mean you'll have symptoms for 15 years. The study looked at hormone changes across many women. It can't tell you when symptoms will start for you, or how long your perimenopause will last.

How they spotted it

Women reach menopause at different ages. Two women born in the same year may be years apart when their periods stop.

So the team looked for changes around the last period, rather than just comparing women of the same age. That helped bring a clearer pattern into view. [1]

They used existing health records and estimated some of the dates. They didn't follow each woman through all those years. The study gives a broad picture of what may happen, rather than a personal timetable.

The changes reached across the body

Around the last period, 52 of the 90 health measures studied in the US showed clear changes compared with men. These included bone measures, liver tests, blood fats such as cholesterol, and tests related to salt and water balance. Men didn't show the same sharp changes. [1]

The authors call this a "physiological cliff." Put simply, they found a marked change around the last period across several parts of the body.

That's why this paper matters beyond the timing of periods or hot flashes. It puts bone health, cholesterol and other aspects of health into the menopause conversation too.

Some results barely changed. Others moved in a helpful direction. Iron and red blood cell measures suggested less anemia. The authors think this may partly reflect the end of blood loss through periods. [1]

The word "cliff" can sound frightening. These results don't mean your health will suddenly drop when your periods stop. They describe changes across a large group, with plenty of room for women to differ.

What hormone therapy adds to the picture

Women taking hormone therapy had smaller changes in many of the tests. This stood out in measures related to bones, the liver, kidneys, and salt and water balance. The researchers found this pattern in both countries. [1]

That opens up a question about how much treatment might change this picture, and who could benefit.

The study can't settle that yet. Women taking hormones may have had better access to care or differed in other ways from women who weren't taking them. The team tried to account for those differences. It still couldn't be sure how much of the result came from the treatment itself.

And the results weren't the same for every test.

This finding deserves more research. It doesn't prove that starting hormones earlier will prevent heart disease, broken bones or other illness. Decisions about whether to take hormones, and when, still need a discussion with a clinician.

What this brings to the perimenopause conversation

For someone in her late 30s or 40s, the paper brings a distant part of life closer. Some hormone changes may begin well before the last period. Later, changes around menopause may reach several parts of the body.

That gives a reason to talk about long-term health before your periods stop. Alongside symptoms, that conversation can include bone health and cholesterol. Which concerns or tests matter depends on you and your health history. The paper didn't test which checkups women should have.

The years before the final period deserve attention in their own right. This paper gives researchers a stronger reason to study them. It also gives women a reason to ask how those years fit into their care.

This article is for education. It doesn't provide a personal diagnosis, screening plan or treatment advice.

References

[1] Pridham G, Hayut Y, Lavi-Shoseyov N, Neeman M, Hovav N, Toledano Y, Alon U. Population-scale reconstruction of menopause dynamics reveals a physiological cliff at the final menstrual period. Nature Medicine, 2026;32:3823-3831. DOI: 10.1038/s41591-026-04614-0. PubMed: 42864411. Findings discussed here come from the full paper, including Figures 2-4 and the Methods and Discussion sections.