Hot flashes and hormone therapy: the science of perimenopause

September 17, 2026

AI Summary

5 min read

The science of perimenopause: what's happening, what helps, and what doesn't

Perimenopause—the transition window before menopause—affects roughly half the human population, yet medicine has neglected it for decades. Now, thanks partly to social media, the conversation has exploded. But with that attention comes a flood of promises, products, and testimonials that can be hard to sort out. Two researchers who have been studying this transition since before it was fashionable—Dr. Nanette Santoro, reproductive endocrinologist at the University of Colorado Anschutz and lead investigator of the three-decade SWAN study following 3,000 women, and Dr. Genevieve Neal-Perry, neuroendocrinologist and chair of UNC OB-GYN—joined Science Friday to separate what we know from what we don't.

What's actually happening under the hood

The common image of menopause—hormones gently petering out while women sit quietly—is wrong. "Hormones are up and down," Santoro said. The SWAN study has shown that perimenopause involves a body-wide set of changes that are dramatic for some, inconvenient for many, and barely noticeable for others.

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What you'll learn

1 (00:28) **Perimenopause: The Neglected Transition** - Introduction to the topic: perimenopause affects billions but has been historically under-studied and under-discussed.
2 (02:22) **“We’re Definitely in a Moment”** - The guests assess the current cultural and scientific climate around perimenopause.
3 (03:02) **What’s Happening Under the Hood** - The biological basics of perimenopause are explained, correcting common myths.
4 (03:40) **Why Symptoms Hit Some Harder Than Others** - Listener calls illustrate the wide range of experiences, from severe distress to no symptoms.
5 (05:25) **The Neuroscience of Hot Flashes** - Dr. Neal-Perry dives into the mechanism linking hormone changes to the sensation of heat.
6 (07:44) **Are All Symptoms Really Perimenopause?** - The hosts question whether social media over-attributes everyday issues to hormone changes.
7 (09:43) **The Wild Ride of Hormone Therapy: The WHI Backlash** - A concise history of why hormone therapy became taboo after the Women's Health Initiative (WHI).

+ Full timestamped outline available in the app

Show Notes

Perimenopause affects more than 4 billion people, but has historically been neglected by medicine. It’s the time before menopause when hormones start fluctuating wildly, leaving women with brain fog, hot flashes, dropping bone density, and mood changes. Thanks in part to social media, it’s more prominent in public discourse than it used to be.

But it’s not just awareness that’s blown up: It’s also the promise that you don’t have to suffer like those before you, thanks to hormone therapy. After decades of controversy over prescribing estradiol and progesterone due to concerns of increased breast cancer and heart disease risk, new research has many providers reconsidering their approach.

Joining Flora to sort out the science are reproductive endocrinologists Nanette Santoro and Genevieve Neal-Perry, who are both running some of the biggest long-term studies on perimenopause and the effects of hormone therapy.

Guests:

Dr. Nanette Santoro is a reproductive endocrinologist at the University of Colorado Anschutz and is the president of the Endocrine Society.

Dr. Genevieve Neal-Perry is a reproductive endocrinologist and the OB-GYN department chair at the University of North Carolina at Chapel Hill.

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