34: Understanding Estrogen: Facts vs. Myths
Ep. 34
In this episode of Reset Recharge, Dr. Komal Patil-Sisodia, a triple board certified endocrinologist and women's health expert, explores the complexities of estrogen therapy. She breaks down bioidentical and synthetic estrogen, compares their safety and effectiveness, and provides evidence-based insights into cardiovascular and cancer risks.
This informative session aims to empower women with the knowledge to make informed decisions about hormone therapy. Dr. Patil-Sisodia emphasizes the importance of understanding individual risk factors and the critical distinctions between FDA-approved and compounded hormone products.
Tune in for a deep dive into estrogen therapy, and learn practical questions to bring to your next healthcare appointment.
Listen to the full episode:
By Dr. Komal Patil-Sisodia | Reset Recharge Podcast | November 17, 2025
Bioidentical vs. Synthetic Estrogen: The Real Evidence Behind Safety, Risks & Hormone Therapy
If you’ve ever felt confused or overwhelmed by conflicting claims about estrogen, you are absolutely not alone.
Today’s deep dive breaks down one of the most misunderstood topics in women’s health:
What’s the difference between bioidentical and synthetic estrogen — and is one actually safer?
You’ve probably heard phrases like:
“Bioidentical hormones are natural.”
“Synthetic estrogen causes cancer.”
“Compounded hormones are safer.”
“Estrogen is risky.”
“Estrogen is life-changing.”
The truth is more nuanced — and more empowering — than the marketing would have you believe.
This guide explains what the science actually tells us about:
Bioidentical vs. synthetic estrogen
FDA-approved estradiol vs. compounded hormone products
Blood clot and cardiovascular risks
Breast and endometrial cancer
Why how you take estrogen may matter more than the type you choose
Let’s pull back the curtain.
What Bioidentical Estrogen Really Means
Bioidentical estrogen is structurally identical to the estrogen your ovaries make — specifically estradiol (and sometimes estriol). These hormones are typically derived from plant sources (like soy or yams) but are chemically modified in a lab so the final molecule matches human estrogen.
➡️ Bioidentical ≠ “Natural”
The term bioidentical is often used as a marketing word. These hormones may start from plants, but they are processed, purified, and manufactured just like other medications.
Common FDA-approved bioidentical estrogen options include:
Estradiol patches
Oral estradiol
Estradiol gels or sprays
Vaginal estradiol tablets, creams, or rings
These products undergo rigorous testing for:
✔ purity
✔ dose consistency
✔ safety
✔ effectiveness
So What Is Synthetic Estrogen?
Synthetic estrogens are estrogen-like compounds that have a different molecular structure than human estrogen.
Two well-known examples:
1. Ethinyl Estradiol
Used in many birth control pills. It’s intentionally designed to be more stable and longer-lasting.
2. Conjugated Equine Estrogens (CEE)
Originally derived from the urine of pregnant horses, used in older formulations of menopausal hormone therapy.
Small structural differences can influence:
How long the hormone stays in your body
How strongly it binds to estrogen receptors
Effects on cholesterol, clotting, and tissue responses
Are Bioidentical Estrogens Automatically Safer?
Short answer: No.
There is no strong, high-quality evidence showing that all bioidentical estrogens are safer than all synthetic estrogens.
Differences often depend more on:
Dose
Whether the estrogen is oral or transdermal
The type of progesterone/progestin used
Individual risk factors
Quality and regulation of the product
FDA-Approved Bioidentical Estrogen vs. Compounded Hormones
When someone says “bioidentical,” they may be referring to two very different things:
1. FDA-Approved Estradiol Products
These have:
Standardized doses
Quality testing
Safety and clinical data
Regulation and oversight
2. Compounded Bioidentical Hormones (Creams, Troches, Pellets)
These are custom-mixed in compounding pharmacies — and not FDA-approved.
Concerns include:
Doses may vary from label claims
Purity and potency are inconsistent
Limited safety data
Not subject to the same quality control
Medical societies (ACOG, NAMS) recommend FDA-approved estradiol first, unless a patient has a specific medical need that compounding is required to meet (e.g., ingredient allergy).
Cardiovascular Risk: Why the Route of Estrogen Matters More Than Type
1. Oral Estrogen (Pills)
Goes through your liver first. This increases:
Clotting factors
Triglycerides
Certain inflammatory markers
2. Transdermal Estrogen (Patches, Gels, Sprays)
Bypasses the liver → tends to be safer for:
Blood clot risk
Stroke risk
Transdermal estradiol consistently shows a lower clotting risk than oral estrogen, especially oral CEE.
Women with obesity, clotting disorders, migraines with aura, or cardiovascular risk factors often benefit more from transdermal options.
Breast Cancer & Endometrial Cancer: What the Evidence Actually Shows
1. Insights from the Women’s Health Initiative (WHI)
CEE + synthetic progestin (MPA) increased breast cancer risk.
CEE alone did not — and in long-term follow-up, may even lower risk.
This means the increased breast cancer risk was tied to:
The combination of estrogen + a specific progestin
Not estrogen itself
Not all hormone therapy
Not “synthetic estrogen” as a category
2. What About Bioidentical Estradiol?
Estradiol + micronized progesterone (bioidentical progesterone):
Appears to have similar or possibly lower breast cancer risk
But we lack large head-to-head clinical trials
3. Endometrial Cancer
If you have a uterus:
Estrogen alone increases endometrial cancer risk
Adding an appropriate progesterone or progestin protects the uterine lining
This applies to both bioidentical and synthetic estrogen.
Key Takeaways for Women Navigating Hormone Therapy
Here’s what I want you to walk away with:
1. Bioidentical estrogen = identical to human estrogen; synthetic = different. Not good vs. bad.
2. FDA-approved estradiol is preferred over compounded hormones.
3. No strong evidence shows bioidentical is universally “safer.”
4. The route matters — transdermal estradiol often reduces clot risk.
5. Cancer risk depends on many factors, including the type of progesterone used.
6. Evidence differences are modest; we need more research.
Questions to Ask Your Clinician
Take these into your next appointment:
Is transdermal estradiol a better option for me than an oral pill?
Can we use an FDA-approved estradiol product instead of a compounded hormone?
What are my personal risks for blood clots, cardiovascular disease, and breast cancer?
Which progesterone or progestin are we using with estrogen, and why?
Hormone therapy should be individualized — not driven by fear or marketing.
Final Thoughts
Estrogen is not something to fear. It’s something to understand. With clarity and evidence, women can make informed, empowered decisions that align with their health goals.
As always, this podcast and blog are for education — not personal medical advice. Please discuss your individual risks and options with a trusted clinician.
If this guide helped clarify the confusing world of estrogen, please share it with someone navigating perimenopause or menopause. Knowledge is power — and sharing it helps more women reset, recharge, and take control of their health.
Disclaimer
This content is for educational purposes only and should not replace medical advice. Always consult your healthcare provider before making decisions regarding screening, testing, or treatment.