Are Bioidentical Hormones Safe?

Hormone replacement therapy for menopause grew to prominence in the 1990s when millions of women were sold hormones made from horse urine. Premarin (from the words pregnant mare urine) was promised to prevent age-related diseases. When the truth got out in 2002 that the opposite was true—it actually increased risk of heart disease, stroke, pulmonary embolism, and invasive breast cancer—the number of prescriptions dropped and so did the rates of breast cancer.

Thanks to some high-profile celebrity endorsements interest then switched to so-called “compounded bio-identical hormones,” from plant rather than equine sources, which were said to work the same without carrying the same risks. But what does the science say?

In my video pick above, I note there’s been several new reviews on the subject from the American College of OB/GYNs, Mayo Clinic, and the editors-in-chief of the journal of the International Menopause Society. They all concluded that bio-identical hormones—being bio-identical!—carried the same risks, benefits, and side effects, which we now know is not a good thing. Even worse, when the FDA actually analyzed bio-identical hormone batches to see if the contents matched the label, nearly a third failed the analysis. Even in the same bottle, the dose of hormones could be all over the place.

How do we know all these medical authorities condemning bio-identical hormones aren’t just in the pockets of drug companies that don’t want the competition? After all, there are literally billions of dollars at stake. Whenever I’m skeptical I turn to The Medical Letter on Drugs and Therapeutics, considered one of the least biased sources in medicine. It’s kind of like the Consumer Reports of the drug world—and, in fact, was actually co-founded by the co-founder of the publisher of Consumer Reports more than 50 years ago. As The Medical Letter likes to brag on their website, they do not accept grants (from any source), donations (from anyone), or funding (from any entity). They won’t let their work be used for promotional purposes and they don’t accept any advertising.

The Medical Letter on Drugs and Therapeutics recently reviewed bio-identical hormones and came to the same conclusion: “There is no acceptable evidence that bio-identical hormones are safe or effective. Patients should be discouraged from taking them.”

Another way to rid oneself of excess estrogen is in the way nature intended. See my video: Relieving Yourself of Excess Estrogen.

We can also stop consuming steroid hormones. See my videos Anabolic Steroids in Meat and Acne & Cancer Connection.

For other ways to decrease breast cancer risk see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 presentation Uprooting the Leading Causes of Death.

Image credit: justthismoment / Flickr

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William C
William C16 days ago

Thank yo.u

W. C
W. C17 days ago


Duane B.
.3 years ago

Thank you for sharing.

Charla D.
Charla D4 years ago

A tremendous amount of relief is available through Chinese herbs (and acupuncture as well, but herbs alone are very effective). I speak from both professional and personal experience. These herbs have been used safely for thousands of years and alleviate symptoms not by suppressing or masking them, the way pharmaceutical drugs do, but by actually healing the deficiencies and imbalances in your body that are the root cause of the symptoms. Most licensed acupuncturists are also skilled with herbal medicine too. If there are no practitioners near you, visit He is a very experienced, qualified practitioner and can do an email consultation and then make herbal recommendations that are appropriate for you. You don't have to suffer. Be well, ladies!

Mac C.
mac C4 years ago

Thanks for the video, important information.

Julie D.
Julie D4 years ago

I learned this about the bio-identicals a long time ago. I chose not to take any kind of "hormone replacment" therapy. Instead I researched to find out what vitamins and minerals women may become less abundant in due to menopause and have taken those vitamin supplements instead in safe reasonable amounts. I no longer have hot flashes or any other problems due to menopause. The risks of "hormone replacement" therapy of any kind are way too scary.

Kay Caldwell

I have sucked it up so long I could scream. If men suffered from the severe symptoms that I have they would demand a cure.

Miranda Parkinson

very good to know,always thought them to be no good!

Cindy Wade
Cindy W4 years ago

I've never considered any form of HRT... I think they're all garbage. Better to just suck it up.

Mary L.
Mary L4 years ago

After 15 years I find I weep daily over ridiculous things. I was hoping. Thanks for the information and update. I'll just keep crying.