Praise for 
Estrogen Matters:

"I hope Estrogen Matters draws enough attention to counter the fears and misinformation about HRT that so many women, and their physicians, still hold." Phyllis Greenberger, MSW, former President and CEO of the Society for Women's Health Research

“Well written, insightful, and hard hitting, Estrogen Matters successfully rebuts the billion-dollar, government-led study known as the Women’s Health Initiative, which claimed that hormones for post-menopausal women are harmful. That study was wrong. It turns out estrogens do matter for women’s health.” — Vincent T. DeVita Jr., MD, Professor of Medicine, Yale School of Public Health and Yale Cancer Center

“If you’re one of the many menopausal women who avoid HRT to treat your symptoms because of all the scary headlines, this book is a must-read.” Jennifer Ouellette, author of Me, Myself and Why

More praise ︎

About the Authors

Avrum Bluming received his MD from the Columbia College of Physicians and Surgeons. He spent four years as a senior investigator for the National Cancer Institute and for two of those years was director of the Lymphoma Treatment Center in Kampala, Uganda. He organized the first study of lumpectomy for the treatment of breast cancer in Southern California in 1978, and for more than two decades he has been studying the benefits and risks of hormone replacement therapy administered to women with a history of breast cancer. Dr. Bluming has served as a clinical professor of medicine at USC and has been an invited speaker at the Royal College of Physicians in London and the Pasteur Institute in Paris. He was elected to mastership in the American College of Physicians, an honor accorded to only five hundred of the over one hundred thousand board-certified internists in this country.


Carol Tavris received her PhD in social psychology from the University of Michigan. Her books include Mistakes Were Made (But Not by Me), with Elliot Aronson; Anger: The Misunderstood Emotion, and The Mismeasure of Woman. She has written articles, op-eds, and book reviews on topics in psychological science for a wide array of publications — including the Los Angeles Times, the New York Times Book Review, the Wall Street Journal, and the TLS — and a column for Skeptic magazine. She is a fellow of the Association for Psychological Science and has received numerous awards for her efforts to promote gender equality, science, and skepticism.

Available in hardcover, ebook, and audio

UK edition, Oestrogen Matters
German edition, Öestrogen!




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To reach the authors:

For inquiries about lecture availability and booking, contact our lecture agent Jayme Boucher:
Hachette Speakers Bureau Director, Hachette Book Group (212-364-1286)


Table of Contents

Introduction: Who Killed HRT?

1.         Does Estrogen Cause Breast Cancer?            

2.         The “Change of Life” and the Quality of Life                 

3.         Matters of the Heart               

4.         Breaking Bad

5.         Losing and Using Our Minds     

6.         Can Breast Cancer Survivors Take Estrogen?           

7.         Progesterone and the Pill               

8.         Debates, Decisions, and Final Lessons in the Case for HRT



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“This is such an important book, I want to do all I can to encourage every woman to read it. Groundbreaking and carefully researched, Estrogen Matters provides essential information about the many benefits of estrogen at menopause and even after a diagnosis of breast cancer. It reveals the misinterpretation of study results that led women (and their doctors) to have unwarranted concerns about estrogen use. The thoughtful information presented here will help women feel more comfortable taking estrogen, leading to healthier, longer lives for many.”Patricia T. Kelly, PhD, specialist in cancer risk assessment and author of Assessing Your True Risk of Breast Cancer

“Having spent over two decades advancing women's health, I was appalled by the Women’s Health Initiative’s efforts to sensationalize and distort their own findings to promote an anti-hormone-therapy agenda. I hope Estrogen Matters draws enough attention to counter the fears and misinformation about HRT that so many women, and their physicians, still hold." Phyllis Greenberger, MSW, former President and CEO of the Society for Women's Health Research

“This book is long overdue, and I salute the authors for their courage and effort (and their clear, witty writing). I believe it is an ethical imperative for all clinicians who treat women in menopause or women with breast cancer to alert their patients to this book. It will not only improve women’s quality of life, but also, on balance of probabilities, extend women’s lives by delaying death from all other causes.” Michael Baum, MD, Professor Emeritus of Surgery and visiting professor of Medical Humanities, University College London

“How could one flawed scientific conclusion become a persuasive juggernaut that changed the practice of women’s health worldwide? In their fascinating account, Bluming and Tavris challenge that conclusion and unpack the reasons for its remarkable impact.” Robert B. Cialdini, PhD, author of Influence and Pre-Suasion

From a review on the "To HRT or not to HRT? At long last, someone has collected the body of studies that explore estrogen and its role in areas such as heart disease, breast cancer, brain function, and bone health. Avrum Bluming, MD and Carol Tavris, PHD share their research, knowledge, and stories from patients in this groundbreaking book: Estrogen Matters. This book doesn’t tell you whether or not you personally should take HRT, but it lays out all the information you might want in order to make an informed decision.” 

For the full review, see:

"This book should be mandatory reading for women of any age and for men who care about any woman. I am a retired physician who specialized in breast disease for more than 40 years and never read a more organized and conclusive evaluation of estrogen and hormone replacement therapy.” — Robert J Rosser, MD

“Well written, insightful, and hard hitting, Estrogen Matters successfully rebuts the billion-dollar, government-led study known as the Women’s Health Initiative, which claimed that hormones for post-menopausal women are harmful. That study was wrong. It turns out estrogens do matter for women’s health.” — Vincent T. DeVita Jr., MD, Professor of Medicine, Yale School of Public Health and Yale Cancer Center

“If you’re one of the many menopausal women who reflexively avoid hormone replacement therapy to treat your symptoms because of all the scary headlines, this book is a must-read. The authors deftly cut through the hype to build a strong, well-reasoned case for challenging the current accepted wisdom.” Jennifer Ouellette, author of Me, Myself and Why

“Given breast cancer’s substantial morbidity, mortality, emotional toll and the vast consequences of its treatment, this frontal salvo on the conventional wisdom of estrogen use is refreshing and welcome. The book will stir a lively debate about the merits of decades of existing clinical research on estrogens and help reframe the way clinicians and patients view the tradeoff between the benefits and risks of hormone therapy.” Jerome P. Kassirer, MD, Distinguished Professor, Tufts University School of Medicine; former Editor-in-Chief, New England Journal of Medicine

This book is an exhaustively researched and meticulously reasoned vindication of HRT. Very enlightening! Bluming and Tavris tell estrogen’s story in a way that is both accessible to the general public and appropriate for professionals. What’s more, they provide valuable insights into understanding research and how even the best randomized controlled studies can lead to unjustified public fears and injudicious clinical recommendations.” Harriet Hall, MD, editor, Science-Based Medicine

"In a thorough, careful and unbiased assessment of all the scientific evidence, Bluming and Tavris show that estrogens are not only not dangerous but beneficial for the vast majority of women suffering from post-menopausal symptoms, whether or not they have had breast cancer.  This extremely valuable message deserves to be widely disseminated." Lord Leslie Turnberg, former President of the Royal College of Physicians

“I was one one those women who regarded HRT as the devil's work, so I approached this book with skepticism. But I found it a real eye-opener. The authors turn a convincing light on weaknesses with the studies and reasoning that led to the wholesale rejection of HRT and on the many benefits to taking it. In addition to being a necessary corrective to the wide pendulum swing against HRT, it's an essential reminder that extreme pendulum swings (which seem to the only ones we get) are always misleading: for this as for all important questions, we need reasoned, nuanced consideration, not of ‘both sides’ but of ‘all sides.’ This book is so important for that insight, as well as for the invaluable information it imparts about HRT.” — Deborah F. Tannen, author of You Just Don’t Understand: Women and Men in Conversation, and You’re the Only One I Can Tell: Inside the Language of Women’s Friendships



Update, 2021: Estrogen Matters…Now More Than Ever

    Since Estrogen Matters was published, we have continued to gather evidence about estrogen’s benefits and to attend closely to any studies that question our conclusions. And we have followed the WHI’s own continuing reports. Here is what we know as of 2021.

    First and foremost, the WHI has walked back virtually all of their early alarmist findings. [1] In recent publications, they reported that estrogen does not increase “all cause mortality” or deaths from heart disease and cancer. Actually, they said, it increases longevity, most notably when begun within ten years of the last menstrual period. It is the best preventative for osteoporotic hip fracture. It is safe and effective when applied vaginally for local symptoms. And, in the most striking about-face from their 2003 headlines that HRT “did not have a clinically meaningful effect on health-related quality of life” for women in menopause, they stated in 2019 that “Hormone therapy is the most effective treatment for managing menopausal vasomotor symptoms.” [2] Now they write that “hot flashes and night sweats affect approximately 70% of midlife women and may persist for a decade or longer,” having significant adverse effects “on sleep, daily functioning, and quality of life.” And by the way, they add that “cognitive and mood symptoms often accompany disruptive hot flashes.” For these reasons, women with frequent, severe menopausal symptoms “may greatly benefit from hormone therapy.” Better late than never, but earlier would have been better for the countless thousands of women the WHI deprived of the “most effective” treatment.

    As for women’s deep-seated fears of breast cancer as their main reason to avoid estrogen, in 2020 the WHI investigators reported a 23% decreased incidence of breast cancer among women randomized to estrogen—after 19 years of follow-up. It’s the combination of estrogen and progesterone (HRT), they still maintained, that raises the risk. [3] But two medical sleuths challenged that finding, which was not statistically significant in 2002, reporting it was due to a statistical misinterpretation: The women on HRT did not have an increased risk; the control group had a reduced risk, because many of the women in that group had been on estrogen before the study! When they were removed from analysis, the supposed increased risk of HRT vanished. [4]

    Finally, more good news for the many women concerned about the safety of pregnancy, when estrogen rises tenfold, following breast cancer. A collaborative study from research institutions around the world concluded that pregnancy following treatment of breast cancer had no negative effect on prognosis, regardless of estrogen receptor assay positivity, after a median follow-up of 7.2 years. And a retrospective, international cohort study of 1,252 breast cancer patients with BRCA mutations, published in 2020, reported no increased risk of breast cancer recurrence associated with pregnancy following treatment. [5]

    Nonetheless, as of this writing in 2021, we have yet to see an NIH press conference convened to reassure women of the benefits of estrogen and publicly explain what was wrong with the original WHI scare stories that many doctors still hold as gospel. On the contrary, whenever someone manages to assemble yet another huge vat of numbers and pull out a tiny but spurious “finding” that can alarm women, headlines follow like a dog after a biscuit. In 2019, the prestigious British journal The Lancet published a paper claiming that HRT increases the risk of breast cancer, generating the inevitable headlines and fears, and so we scrutinized it closely. Once again, the data did not support the alarm. [6]

    We are still waiting for that press conference.


[1] Stuenkel CA, Manson JE. Women’s Health – Traversing medicine and public policy. N Engl J Med 2021;384: 2073-6.

[2] Shifren JL, Crandall CJ, Manson JE. Menopausal hormone therapy. JAMA 2019;321:2458-9.

[3] Chlebowski RT, Anderson GL, Aragaki AK. Association of menopausal hormone therapy with breast cancer incidence and mortality during long-term follow-up of the Women’s Health Initiative Randomized Clinical Trials. JAMA 2020;324:369-80.

[4] Hodis HN, Sarrel PM. Menopausal hormone therapy and breast cancer: what is the evidence from randomized trials? Climacteric 2018;21:521-8.

[5] Lambertini M, Kroman N, Ameye L. Long-term safety of pregnancy following breast cancer according to estrogen receptor status. J Natl Cancer Inst 2018;110:426-9. Lambertini M, Ameye L, Hamy A-S, et al. Pregnancy after breast cancer in patients with germline BRCA mutations. J Clin Oncol 2020;38:3012-23.



In this section we report some major findings that were published after Estrogen Matters was published (2018) or that we learned about subsequently. Physicians and researchers who are interested in professional updates, with references, are welcome to contact Dr. Bluming at

Another scare story bites the dust. “Does hormone therapy cause dementia? A Danish study suggests it does. Here’s why it’s wrong.”
Avrum and Carol’s op-ed in the Baltimore Sun, July 27, 2023.

The Cancer Journal, May/June 2022, special issue: Estrogen Reconsidered: Exploring the Evidence for Estrogen’s Benefits and Risks

As the Guest Editor of this issue, Dr.  Bluming invited updated articles from investigators around the world, all of whom have contributed to our current understanding of the benefits vs. risks of estrogen (and estrogen-progesterone, as HRT) when administered to peri- and postmenopausal women. Articles include a review of administering estrogen to breast cancer survivors; its effects on the heart; pregnancy following breast cancer; estrogen and testosterone for women in menopause and any associated risks of developing cancer; concerns about compounded bioidenticals; and others.


Many women are interested in bioidentical hormones, an issue that causes great confusion. Regulated bioidentical hormones are FDA approved and marketed by commercial pharmaceutical companies. But bioidenticals made by compounding pharmacies are completely unregulated by the FDA, and can contain useless or even harmful ingredients.

In 2020, the National Academies of Science confirmed once again the unreliability of compounded bioidentical hormones in menopause:

"After 21 months of data collection and analysis, the NASEM committee’s overarching conclusion was, “Given the paucity of data on the safety and effectiveness of cBHT…there is insufficient evidence to support the overall clinical utility of cBHT as treatment for menopause.”

Cynthia A. Stuenkel, JoAnn E. Manson, “Compounded Bioidentical Hormone Therapy: The National Academies Weigh In.” JAMA Internal Medicine, published on line December 14, 2020.

Compounded bioidentical hormone therapy is not supported by the National Academies of Sciences, Engineering and Medicine.

“There is insufficient evidence to support the overall clinical utility of compounded bioidentical hormone therapy as treatment for menopause.”

For the full report, see:
National Academies of Sciences, Engineering, and Medicine 2020. The Clinical Utility of Compounded Bioidentical Hormone Therapy: A Review of Safety, Effectiveness, and Use. Washington, DC: The National Academies Press.

We urge women who are confused about bioidenticals to read this superb review by Cathryn Jakobson Ramin:


Remember this:  Prevagen does not prevent memory decline: "Jellyfish Memory Supplement Prevagen Called 'Clear-Cut Fraud.’”

See Dr. Anthony Pearson’s article in MedPage Today:

Even the most recently tested sophisticated approaches in preventing cognitive decline and Alzheimer’s (exercise, diet, vitamins, etc.) have been unsuccessful:

Estrogen, which has been repeatedly shown to reduce the risk of cognitive decline, is often omitted from suggested options.


A retrospective, international cohort study of 1,252 breast cancer patients with BRCA mutations reported no increased risk of breast cancer recurrence associated with pregnancy following treatment, even among patients with  ER+ tumors. See:

Estrogen treatment inhibits up to 30% of triple negative breast cancers.

Pregnancy after breast cancer is safe and does not fuel recurrence of the cancer.

There is no increased risk of breast cancer following in vitro fertilization (IVF), a process involving marked elevation of estrogen levels due to ovarian stimulation, even among BRCA1 and BRCA2 mutation carriers. This finding has been extended to include no increased risk of breast cancer recurrence among breast cancer survivors treated with IVF.

Sergentanis  TN, Diamantaras A-A, Perlepe C, et al. IVF and breast cancer: a systematic review and meta-analysis. Hum Reprod Updata 2014;20:106-23.

Derks-Smeets IAP, Schrijver LH, de Die-Smulders CEM, et al. Ovarian stimulation for IVF and risk of primary breast cancer in BRCA1/2 mutation carriers. Br J Cancer 2018;119:357-63.


In 2020, the BMJ published a study reporting  an increased risk of breast cancer with both estrogen alone and with the combination of estrogen/progesterone.

The study reported a small difference that, even if valid, would not have been mentioned had the end point been pancreatic cancer (not breast cancer), and omitted all the medical benefits of taking HRT. Dr. Bluming’s letter critiquing the study was published online, and can be found here:

Much Ado About Little: More False Alarms from Lancet

In 2019, the British journal Lancet published a paper claiming, once again, that Hormone Replacement Therapy (HRT)—also called Menopausal Hormone Therapy (MHT)—increases the risk of breast cancer. Naturally, this article generated more headlines designed to frighten women away from hormones rather than guide them to an informed decision. And once again, a close reading of the study reveals that the data do not support the alarm.

Fortunately, some skeptical reporters actually looked at the data: 

Millions of women are missing out on hormone replacement therapy: This much maligned treatment could save many lives.
By Natasha Loder, The Economist:

& Media

Avrum and Carol have been interviewed for numerous podcasts and media, including:

Avrum and Carol were keynote speakers at The New Pause Symposium, a menopause conference hosted by Naomi Watts and Alisa Volkman, March 11, 2023.

Susan Dominus,  "Women Have Been Misled About Menopause,” The New York Times, Feb. 2, 2023:

Margit B. Weisgal, "All About Menopause: Clearing the air on what is safe and what is not,” the Baltimore Sun, Prime Time Living, June 21, 2023.

Cynthia Thurlow, “Dispelling myths about hormone replacement therapy,” Everyday Wellness, March 12, 2022:

Katie Taylor, Women’s Midlife Festival, London, Sept. 27, 2021:

Selene Yeager: “Hit Play Not Pause,” July 28, 2021:

Dr. Chana Davis, Menopause/hormone therapy Part 2. Fact or Fiction? February 18, 2021:

Katie Taylor, November 1, 2020:
To commemorate International Menopause Day this past October 18th, Dr. Avrum Bluming was interviewed by Katie Taylor, CEO of the Latte Lounge in London. Here are excerpts from that recorded  interview:

Amanda Thebe, “Over 40 Fitness,” August 16, 2019:

Jim Underdown, Executive Director, Center for Inquiry West, May 20, 2019:

The Center for Inquiry focuses on promoting science and skepticism—examining the evidence for ideas that are outdated, harmful, or wrong.

Dr. Chris Duff of FundRx, May 6, 2019:

FundRx Venture Partner Perspectives was created to share the knowledge and opinions of a diverse array of healthcare clinical and industry experts. In this extended conversation, Avrum and Carol discuss Estrogen Matters and updates since the book’s publication.

Danny Lennon, Sigma Nutrition Radio, April 23, 2019:

Danny Lennon is founder of Sigma Nutrition Radio, which conducts weekly interviews with researchers on topics that apply to evidence-based practice in health and nutrition.

Jill Angelo and Dr. Rebecca Dunsmoor-Su of genneve, April 12, 2019:

A 40-minute podcast with Jill Angelo, CEO of genneve, a website devoted to providing women in menopause with the best information available and Dr. Rebecca Dunsmoor-Su, an ob-gyn and epidemiologist.

Dr. Peter Attia’s Drive Podcast, February 26, 2019:

Dr. Peter Attia, a Stanford/Johns Hopkins/NIH-trained physician, hosts long-form (“ultra-deep-dive") conversations with researchers on new and important directions in medicine. The Peter Attia Drive Podcast is a weekly podcast focusing on health, longevity, well-being, and critical thinking in science. Avrum and Carol spoke at length.

You can download podcast #42 here:

Dr. Barb (MiddlesexMD), “the fullness of midlife,” January 10, 2019:

Avrum and Carol did a featured podcast on Dr. Barb (DePree’s) MiddlesexMD website, “the fullness of midlife.”  Dr. Barb, an ob-gyn, has been an enthusiastic supporter of Estrogen Matters and begins the conversation saying, "This book is exactly what I needed to read, and I am so thrilled someone took on this project.”

The Los Angeles Times ran an opinion essay by Avrum and Carol, January 31, 2019: