What if one hormone could slash your risk of heart disease, stroke, breast cancer, and Alzheimer’s by 60%?

That’s the potential of estrogen therapy done right, according to emerging research presented last month at the annual meeting of The Menopause Society. 

Estrogen isn’t just about hot flashes and menopause. It's the master regulator of female longevity; when started at the right time, it can literally slow biological aging. 

Yet only 5% of women are currently using HRT (JAMA Health Forum, 2024).

Why? Two decades ago, estrogen’s reputation was destroyed overnight. A misreading of the Women’s Health Initiative (WHI) study in the early 2000s led to widespread fear that hormone therapy caused breast cancer. 

Yesterday, the U.S. government announced it is finally removing the black box warning on menopausal HRT to reflect the latest understanding of the research.

Here’s what you need to know. 

🤓 What to know: Estrogen is the master regulator of women’s longevity.

I’ve said it before and I’ll say it again: there’s no better longevity drug for women than estrogen.

The fresh data presented at The Menopause Society backs that up big time. Researchers analyzed 120M+ medical records and found:

• Women who began estrogen therapy in perimenopause and stayed on it for 10+ years had a 60% lower risk of breast cancer, heart attack, and stroke.

• Women who started HRT after menopause had a slightly lower risk of breast cancer and heart attack but a 4.9% higher risk of stroke. 

🌟 Benefits of estrogen:  

The Menopause Society data backs up the last two decades of research on estrogen and longevity: 

🧠 Brain

• Estrogen supports mood, memory, and cognition (serotonin, dopamine, glutamate, gaba, and BDNF expression) → estrogen loss is linked to brain fog and higher Alzheimer’s risk (Frontiers in Molecular Biosciences, 2025).

💪 Muscle + Metabolism 

• Estrogen helps maintain lean mass and insulin sensitivity → when estrogen drops, risk for metabolic syndrome and diabetes increases (Biomedicines, 2023). 

🦴 Bones

• Regulates bone remodeling → women can lose up to 20% of bone density within 5 years of menopause without HRT (Endocrine Society).

❤️ Heart

• Maintains flexible arteries and healthy cholesterol → estrogen decline spikes post-menopausal heart disease risk (Archives of Medical Science, 2022). 

🔥 Inflammation 

• Acts as a systemic anti-inflammatory → drop in estrogen accelerates cellular aging (JAMA Network Open, 2024).

💦 Skin + Sexual Health

• Boosts collagen, hydration, elasticity

❌ Why did estrogen become the villain? 

In the early 2000s, the Women’s Health Initiative (WHI) study sent shockwaves through medicine. It reported that hormone therapy increased the risk of breast cancer, heart disease, and stroke. Millions of women stopped HRT overnight.

But here’s what was missed:

• The WHI used oral synthetic hormones (Premarin and Provera), not bioidentical estrogen.

• Most participants were 10+ years past menopause, when arteries and tissues were already less responsive.

In other words: the wrong hormones, given to the wrong women, at the wrong time.

Later analyses of the WHI data flipped the script. Estrogen, when started early and dosed right, reduces the very risks we feared.

⏳Why estrogen matters after 35

Estrogen is not just a “menopause hormone.”

It peaks in your 20s and early 30s, starts decreasing in your late 30s, and plummets 85–90% during menopause (Trends in Molecular Medicine, 2013). 

 Estrogen comes in 3 forms: 

• Estradiol (E2) – strongest, dominant pre-menopause

• Estrone (E1) – made after menopause from fat

• Estriol (E3) – weaker, dominant in pregnancy; used in vaginal estrogen

Estrogen is made in your:

• Ovaries (main source pre-menopause)

• Adrenals + body fat (post-menopause backup system)

• Muscle (converts testosterone into estrogen via aromatase)

🚨This is why women with more muscle and better adrenal health tend to have smoother transitions into menopause. 

🔍 Hormone therapy: What we know now

When started within 10 years of menopause (or before age 60), estrogen therapy can:

✅ Lower risk of cardiovascular disease and all-cause mortality (Cancer Journal, 2023)

✅ Lower risk of osteoporosis and fracture (Osteoporosis International, 2022)

✅ Lower risk of Alzheimer’s disease (Alzheimer’s Risk and Therapy, 2024)

✅ Slow biological aging (JAMA Network Open, 2024)

✅ Improve ability to build and maintain lean muscle mass post-menopause (Frontiers in Physiology, 2021)

⚠️ For women with a history of breast cancer, systemic HRT is generally not recommended because of recurrence risk. Local estrogen (like vaginal estriol) is often safe—always consult your provider (Menopause, 2025).

💪 What to do: Track hormones after 35, work with a hormone-literate provider, start HRT within 10 years of menopause.

Every woman should have an informed conversation about the benefits of estrogen as a longevity tool. 

🧪 Step 1: Start tracking hormone levels at 35.

Get baseline levels of:

• Estradiol (E2)

• Progesterone

• Tesosterone

• FSH and LH (for menopausal status)

• SHBG (affects free hormone availability)

• Thyroid + metabolic markers (they influence hormone balance)

Hormone levels can fluctuate wildly during perimenopause but tracking early can help you notice trends over time.

⌚Step 2: Use a wearable & track symptoms.

• Devices like Whoop can help flag changes in sleep, temperature, or cycle length—early clues that your hormones are shifting.

• Pair this with a symptom log. Symptoms + hormone levels + cycle trends help inform your treatment plan.

🌿 Step 3: Support estrogen naturally.

HRT works best alongside lifestyle medicine:

• Prioritize protein + resistance training for bone and muscle

• Balance blood sugar to reduce estrogen dominance

• Manage stress and sleep to stabilize cortisol, which affects estrogen metabolism

🧑‍⚕️Step 4: Find an HRT-literate provider.

If your PCP or gyno is telling you HRT is dangerous, their information is out of date. 

Work with someone who understands:

• Bioidentical hormones

• Timing windows

• Your unique health history and risk profile. Smart estrogen therapy is highly individualized. The point is to have an informed conversation early.

Like my board-certified team at Parsley. This is our jam. 

⏳ Step 5: Start HRT within 10 years of menopause.  

• Starting estrogen therapy within 10 years of menopause onset lowers risk for heart disease, dementia, and bone loss (International Journal of Women’s Health, 2014).

• The new data makes the case that earlier is even better. Ask your doctor whether starting during perimenopause might be right for you. 

💊 Step 6: Consider bioidentical estrogen. 

Bioidentical = matches your body’s own hormones

• Transdermal patches (like Vivelle-Dot) = bioidentical, best-tolerated

• Compounded creams = flexible dosing for in-between needs

• Vaginal estriol = minimal systemic absorption

👉 Start low, go slow. Most women feel best with levels that mimic their 20s–30s (E2: 50–100 pg/mL).

⚡️ Quick Hits

🎾 Tennis is the #1 sport for longevity

A 25-year study found people who play tennis live nearly 10 years longer than sedentary peers, outpacing those who prefer cycling (+3.7), swimming (+3.4), jogging (+3.2) and gym-goers (+1.5). Why? Researchers think the combo of movement and built-in social connection gives tennis an edge. 

Time to grab a racket?

🩸The best-priced full functional labs—finally 

Run, don’t walk people! Parsley Health now offers the most affordable comprehensive lab panel on the market covering 80+ labs (hormones, inflammation, metabolism and more) for just $350. The best part? Only 1 lab draw is needed for the full panel. (The other companies out there make you go twice in a week—who has time for that?) 

Sign up here!

🧬 Mitochondrial reboot in a pill?

A new 4-week trial found that 1,000 mg of urolithin A made immune cells act younger, rewiring them to burn cleaner, mitochondria-powered fuel instead of quick sugar. The result: stronger immune readiness without added inflammation.

A Urolithin A supplement may also help you maintain lean muscle mass.

💛 The Momgevity Files

Last week, I took three days for a solo retreat in Santa Fe.

Between new product launches, nonstop kid chaos, and the general pace of life, I realized I couldn’t hear myself think. So I asked my husband to hold down the fort so I could take a few days to pause—reset my nervous system, reflect on 2025, and plan for 2026.

I chose Santa Fe intentionally. I considered LA, but I knew I’d get pulled into the office and swept up in social plans or work commitments. Instead, I picked somewhere I’d never been known for its art, landscapes, and vortexes: places believed to amplify clarity and transformation.

It delivered.

I had Tibetan energy work from an incredible healer (who told me I’ll be fully fertile until 53!!—not testing that theory 😅). I went to Ten Thousand Waves, the famous Japanese hot spring spa, and had one of the best massages of my life. I drove to Taos for a blue-sky hike along the Rio Grande Gorge, journaled leisurely over an egg-and-mushroom rice bowl, wandered galleries, and met up with my friend and long ago yoga teacher, Elena Brower, whose new book Hold Nothing is about to launch.

Elena recommended the Upaya Zen Center, where I joined two 7 a.m. meditations—just me in my sweats and twenty monks in black robes. It was humbling, quiet, and exquisite.

Each day, I set aside time to write, reflect, and ask myself: The past 10 years have been extraordinary. What do I want for the next 10?

If all of this sounds indulgent—it is. That’s the point. It’s also essential.

One of the real keys to longevity, at least in my life, is creating space. I’m not great at slowing down or saying no—it’s just not in my nature. If I don’t carve out time intentionally, it won’t happen. So I treat it like a work trip. Only in this case, it was a self-led reset.

The insights I found weren’t the kind that come during a walk around NYC.

In meditation, my son appeared to me—with clarity about what he needs from me as an ADHD mom. I also found direction for where I see Parsley going in the new year (more on that soon).

Reconnecting with Elena reminded me why I fell in love with this medicine in the first place. Fifteen or so years ago, in a workshop, she had us write out our dream lives in detail. What I wrote that day became the blueprint for everything I’ve done since.

One of the biggest realizations from this trip: I’ve spent much of the last decade in CEO mode—and I miss doctor mode. That’s why I love writing this newsletter. It’s a passion project that keeps me close to the medicine I fell in love with years ago, and the reason I created Parsley and the life I live today.

In longevity, we talk a lot about sleep, supplements, and recovery but not enough about reflection. And reflection, by definition, requires space. Space to listen. Space to reorient toward what matters.

If you can, take a sacred pause. A day, a weekend—something just for you. Step far enough away from the noise to hear your own thoughts again.

One of my best friend’s moms always said, “Where your eyes go, your car goes.”

Sometimes, when you can’t see what’s ahead, you just need to stop, reset your gaze—and let the vision for what’s next come into view. Once your eyes can see it, the rest will follow.

Stay strong, stay curious, and breathe. 

Robin

As always, this newsletter is for informational and educational purposes only and is not intended as medical advice. Always consult your healthcare provider before making any health decisions or changes to your treatment plan.