17 Fascinating Facts that often surprise women about Menopausal Hormone Therapy:

1. Your Body Made More Testosterone Than Estrogen Before Menopause

Before menopause, women actually produce three times as much testosterone as estrogen. Yet testosterone decline and its role in menopause symptoms is rarely discussed. This explains why some women still feel exhausted, unmotivated, or have low libido even when their estrogen is adequately replaced.

2. The Route Matters More Than You'd Think

Taking estrogen as a pill versus applying it to your skin creates fundamentally different effects in your body. Oral estrogen passes through your liver first, which activates your blood clotting system and can affect cholesterol and other proteins. Transdermal estrogen bypasses the liver entirely, which is why it doesn't increase blood clot risk. Same hormone, completely different safety profile.

3. MHT Isn't Just "Replacing What You Lost"

In 85% of women, certain adrenal androgens (DHEAS, DHEA) actually rise unexpectedly during menopause, even as estrogen falls. Your hormonal landscape during menopause is complex and individual—it's not simply about everything declining together.

4. The "Scared Away from HRT" Era Was Based Largely on One Type of MHT

The Women's Health Initiative study that frightened women (and doctors) away from MHT in 2002 used primarily oral conjugated equine estrogens (from pregnant horses' urine) plus a synthetic progestogen called medroxyprogesterone acetate. The participants were also older (average age 63) and many were starting MHT years after menopause. These findings don't necessarily apply to younger women using modern bioidentical estradiol patches or gels with micronized progesterone.

5. Progesterone Isn't Just One Thing

"Progesterone" is often used as a catch-all term, but there's a significant difference between:

Micronized progesterone, like Utrogestan (bioidentical to what your body made)

Synthetic progestogens (like norethisterone, dydrogesterone, or the older medroxyprogesterone)

They have different effects on breast cancer risk, blood pressure, and side effects. Micronized progesterone and dydrogesterone appear to have lower breast cancer risk than older synthetic versions.

6. Body Weight Affects MHT's Breast Cancer Risk—But Backwards from What You'd Expect

MHT has the least impact on breast cancer risk in women with overweight or obesity, and the greatest impact in normal-weight women. This is counterintuitive and not fully understood, but it's important information for decision-making.

7. There's a "Window of Opportunity" for Heart Protection

Starting MHT under age 60 or within 10 years of menopause appears to be neutral or possibly protective for your heart. But starting it much later—particularly if you already have vascular disease—can increase cardiovascular risks. This "timing hypothesis" explains why older studies showed different results than newer ones, and it means the conversation about MHT for a 52-year-old is very different from one for a 72-year-old.

8. Vaginal Estrogen Is Remarkably Safe

Low-dose vaginal estrogen (for genitourinary symptoms) doesn't increase breast cancer risk, doesn't require additional progesterone, and is often considered safe even for many breast cancer survivors. Yet many women suffer with symptoms for years without knowing this option exists or that it's separate from systemic MHT.

9. You Can't Rely on Blood Tests to Guide Dosing

Unlike thyroid medication or diabetes management, measuring estradiol levels isn't routinely useful for adjusting MHT doses in most women. Treatment is primarily guided by symptom relief and side effects, not by achieving specific blood levels. This surprises many women who expect regular blood monitoring.

10. Bone Protection Happens Quickly, But Doesn't Completely Disappear When You Stop

MHT provides significant bone protection—reducing fracture risk by 20-37%—and this benefit begins relatively quickly. While protection lessens after stopping MHT, there's no "rebound" increase in fracture risk. Your bones don't suddenly become more fragile than they would have been without MHT.

11. The Intrauterine System (IUS) Can Provide the Progesterone Part

Many women don't realize that a hormone-releasing IUD (like the Mirena) can serve as the progestogen component of MHT while also providing contraception during perimenopause. This means you can use estrogen (often transdermal) with the IUS instead of taking daily progesterone pills.

12. Perimenopause Can Be Harder to Treat Than Postmenopause

During perimenopause, your ovaries are still producing fluctuating (sometimes high) levels of hormones. Adding MHT on top of this unpredictable hormonal chaos can lead to irregular bleeding and inconsistent symptom control. This is why some perimenopausal women struggle more with finding the right treatment than postmenopausal women.

13. Unscheduled Bleeding on MHT Doesn't Automatically Mean Cancer

While any unexpected bleeding should be investigated, it's actually quite common—affecting up to 40% of MHT users, especially in the first 3-6 months. Recent years have seen a significant increase in unscheduled bleeding referrals as more women use estrogen gels with micronized progesterone. Most cases aren't cancer, but investigation is still important.

14. MHT Can Actually Help With More Than Just Hot Flashes

While vasomotor symptoms get most of the attention, MHT can also help with:

Joint and muscle aches (particularly common in Asian women)

Sleep quality (beyond just reducing night sweats)

Mood and motivation

Brain fog and concentration

Urinary urgency and recurrent UTIs

Sexual function (both from estrogen and potentially added testosterone)

15. There's No Mandatory Time Limit

Unlike what many women have been told, there's no rule that you must stop MHT after 5 years. Current guidance emphasizes that MHT can be continued as long as benefits outweigh risks for your individual situation. Some women use it for a few years; others benefit from longer-term use, particularly for bone protection.

16. "Bioidentical" Isn't a Magic Word

Many compounded "bioidentical hormone" preparations aren't regulated, tested, or standardized the way prescription MHT is. However, many standard prescription MHTs actually are bioidentical (like estradiol patches and micronized progesterone)—they're just properly regulated and studied. The term "bioidentical" has been somewhat co-opted by the compounding industry.

17. Most Women with Chronic Conditions CAN Use MHT Safely—With the Right Type

Having diabetes, high blood pressure, migraine, or even a history of blood clots doesn't automatically exclude you from MHT. It means you need careful selection of type and route (usually transdermal estrogen with appropriate progestogen) and close monitoring. The blanket "no" many women receive often isn't evidence-based with modern formulations.

These facts highlight how much our understanding of MHT has evolved and how individualized treatment needs to be. The conversation should be nuanced, not scary, and should recognize that your situation is unique.