Mice Don’t Menstruate: It’s Time to Prioritize Women’s Hormonal Health

Sharon Kedar is Co-Founder, Partner of Northpond Ventures. 

Lucy Pérez is a Senior Partner in McKinsey & Company and the Global Leader of the McKinsey Health Institute. 

Shelley Zalis is the Founder and CEO of the Female Quotient. 

This article was originally published in LinkedIn Articles.

It was inspired by the May 2024 episode of Innovate and Elevate with Dr. Donald Ingber, Founding Director of Harvard’s Wyss Institute, who discussed the concept of Mice Don’t Menstruate on the podcast episode “Mice Don’t Menstruate: Advancing Women’s Health with Organ-Chip Technology”. Please send any inquiries to media@npv.vc. 

Before clinical research is conducted on humans, it typically involves animal testing. And in the preclinical world, the most common model is the mouse. Mice are cost-effective, widely available, and share about 85–90% of their genes with humans. 

But here’s the catch: mice don’t menstruate. 

Unlike women, mice experience an estrous cycle—a hormonal cycle without menstruation. When researchers use mice to model women’s health, particularly for reproductive and hormonal conditions, they’re starting from a flawed baseline. That matters—especially for the 51% of the population who will experience menopause if they live long enough. And with all due respect to female mice (and the brilliant scientists who work with them), mice simply can’t model the full complexity of women’s hormonal journey. 

Hormones are not just reproductive—they’re a vital operating system for the health of women across their lives. Most girls begin menstruating between ages 11 and 14 and experience monthly cycles through their childbearing years. As they approach their 40s (or even late 30s,) they enter perimenopause, characterized by irregular menstrual cycles and fluctuating hormone levels. Perimenopause turns into menopause for all women. Menopause officially beings 12 months after a woman’s final menstrual period.  

Both perimenopause and menopause are often underdiagnosed and misunderstood for women and the people who are closest to them.  Symptoms may mimic ailments of modern-day life, which is why they are so often dismissed or misdiagnosed—even by well-meaning providers.  For many women, the experience goes far beyond hot flashes, including symptoms that range from anxiety, sleep disturbances, and brain fog, and heart palpitations to decreased libido. 

Even though this transition affects half of adults, it remains one of the most poorly understood and underfunded areas of healthcare. In 2023, only 13 clinical drugs and therapies, including those used for other conditions, were in development for menopause symptom management, according to the McKinsey Health Institute.  For comparison, diabetes had 580 drugs in development in 2023.  It should not be surprising that the women’s health gap extends beyond menopause, and that women spend 25% more of their lives in poorer health compared to men. And given the lack of research and investment, it’s also unsurprising that some commercial “solutions” for menopause may be scientifically dubious.   

What accounts for the chasm in menopause knowledge? 

First, there’s a training gap for providers.  A 2019 survey of residents in family medicine, internal medicine and ob-gyn found that 20% reported not having any menopause lectures during residency, and under 7% said they felt prepared to support women experiencing menopause. Only around a third of US OB/GYN residency programs offer structured training. If doctors don’t know what to look for, they can’t offer the right care. 

Second, there’s no definitive test. Perimenopause and menopause are clinical diagnoses—based on symptoms, medical history, and physical exams. There is no single, validated diagnostic test that provides a clear answer. 

And third, there’s lingering fear around hormone therapy. For roughly two decades starting in 2002, many US women and providers relied on a now-outdated guidance that linked hormone replacement therapy (HRT) to an increased risk of breast cancer and heart disease. Today, there is updated guidance on HRT’s benefits that highlights a need for more individualized approaches. 

We can do better.  

We need to modernize medical education. Menopause needs to be part of structured education beyond OB/GYNs. Specialists across medical fields should receive training in how menopause can influence health outcomes for a range of conditions beyond reproductive health, such as for bone and brain health.

We need to make hormone therapy a part of a stigma-free conversation. HRT—estrogen alone or combined with progesterone—can offer benefits for many women when started during perimenopause or within 10 years of menopause onset. Every woman deserves to have the conversation with an informed provider.  

We need to increase investment in women’s health research. The conditions of premenstrual syndrome (PMS) along with menopause, maternal health, cervical cancer, and endometriosis make up 14% of women’s health gap — time spent in poor health or time lost from dying too early — but receive less than 1% of research funding across major global health priorities. The next chapter of drug testing is likely to involve more AI-based computational modeling, but those systems can only learn from accurate data sets that address sex-based differences. This highlights the need for menopause research investment to involve deeper understanding of female biology to expand treatment options.

Menopause is a phase of life—not a fading of life. When we equip women and their families with the knowledge and care they deserve, we enable them to thrive—not just survive—through this transition.  

Let’s build a future where every woman can live more days in full health—with dignity, with support, and with a healthcare system that better understands the arc of her health journey.