Dr. Mache Seibel does to estrogen and hormone replacement therapy what other breakthrough thinkers did to our fear of fats – debunk, educate and assure that there is a time and place for the vilified estrogen. A must-have in any woman’s book library.
Magdalena Wszelaki - Certified Nutrition Coach


Dr. Mache Seibel does to estrogen and hormone replacement therapy what other breakthrough thinkers did to our fear of fats  – debunk, educate and assure that there is a time and place for the vilified estrogen. A must-have in any woman’s book library.

Magdalena Wszelaki

Certified Nutrition Coach

Founder: Hormone Balance


Dr. Mache Seibel’s meticulously documented estrogen window concept as to when to use estrogens, in my opinion, is brilliant and the first time I’ve ever seen it explained so clearly. This book should be read by every woman who wishes to improve her quality of life in the peri and post-menopausal years. 

Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N.

Co-Author, HeartSense for Women and Health Revelations from Heaven and Earth


Although there is no romance or hot sex in, “The Estrogen Window,” I couldn’t put this book down! I have been longing for a doctor to write a book that will help women clearly understand the benefits of estrogen, when to use it, and how. Thank you, Dr. Seibel, for giving us all the information, studies and tools to help keep us healthy and happy through menopause and beyond.

Ellen Dolgen, Speaker, Author, Blogger, and Health & Wellness Advocate

 Founder and President of Menopause Mondays at EllenDolgen.com


The Estrogen Window is the first clear explanation I’ve read about the confusing and scary topic of estrogen. What I learned will not only be helpful to me; it will also help me be a better mentor to the hundreds of women entrepreneurs I teach around the world.

Lisa Sasevich

Queen of Sales Conversion

The Invisible Close



Dr. Mache Seibel’s book, The Estrogen Window, introduces a new era of understanding hormone replacement therapy as well as a new level of clarity for controversial topics of medicine. The forces that coax experts towards trends and habits and pull them away from hard science are insurmountable to nearly all. Dr. Seibel manages to give us an unbiased read on the clear message from the vast world of hormone replacement research. He gives a case that will satisfy the most technical readers and summarizes his perspectives into action steps that give clear direction to both experts and lay audiences. This is now the top book on hormone replacement that I will recommend to my patients and peers. 

Alan Christianson, NMD

NY Times Best Selling Author – The Adrenal Reset Diet



Finally!  A clear and easy-to-understand explanation about estrogen!  Dr. Mache eliminates the confusion that has caused so many women to freeze during an important stage that each woman on the planet experiences.  Now, every woman can know how to take back control of their lives during this time in order to make it her best years ever!  I’m recommending every woman I know to read this book.

Sandra Yancey

Founder and CEO

eWomenNetwork, Inc


“I strongly encourage all midlife women and their physicians to read Dr. Seibel’s book, “The Estrogen Window,” which artfully explains and compilates the latest research on menopausal hormone therapy in an elegant and easy to understand fashion helping women to Be Strong, Be Healthy and Be in Charge!”

Holly L Thacker MD FACP NCMP CCD

Executive Director, Speaking of Women’s Health

Director of the Cleveland Clinic Center for Specialized Women’s Health



In his new book, The Estrogen Window, Mache Seibel, MD has created a breakthrough guide to coach women through menopause. He clarifies how to manage menopause symptoms, balance the risks and benefits of hormone therapy, the best time to consider treatment, and how to communicate effectively with your doctor. Highly recommended for anyone dealing with menopause issues.

Steven Masley, MD, FAHA, FACN, FAAFP, CNS, best-selling author of Smart Fat and The 30-Day Heart TuneUp and creator of top public television programs: 30 Days to a Younger Heart and Smart Fats to OutSmartAging.



In The Estrogen Window, Dr. Mache Seibel tells us everything we need to know about one of the most frequently prescribed medications in America. The crucial message is one women have known for millennia: timing is everything.

Julie Holland, MD

Author, Moody Bitches: The Truth About The Drugs You’re Taking, the Sleep You’re Missing, the Sex You’re Not Having, and What’s Really Making You Crazy



Dr. Mache Seibel has made a major contribution to women’s health in writing The Estrogen Window. As both a scientific expert on menopause and an expert in communicating to women, he has beautifully clarified the confusing topic of should women take estrogen as they go through menopause.

Dr. Mache explains the data, and puts it into a perspective that will explain safe usage of the most effective therapy for menopausal symptoms. All women making choices on menopausal interventions will benefit from reading this book.

Mary Jane Minkin, MD, FACOG, NCMP

Clinical Professor, Department of Obstetrics, Gynecology and Reproductive sciences

Yale Medical School


Selected by his peers as one of the Best Doctors in America, Doctor Seibel brings innovation to health education, focusing on creative approaches to help America stay well. He is a national expert in helping women in and around menopause improve their symptoms including sleep, stress, diabetes and weight control. In addition to patient care, Doctor Seibel does corporate consulting, speaking, workshops, and coaching.

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