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 4-min. video Plant-Based Bioidentical Hormones, 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:

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 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image credit: AdamSelwood / Flickr

  • TeCu

    Does anyone have information about the benefits and risks of the alpiste milk in human?

  • Dave

    On hormones, what does The Medical Letter on Drugs and Therapeutics have to say about testosterone replacement in men?

  • Changing

    I’ve been on the Combipatch (“bioidentical” estradiol but synthetic progesterone) for about a year and a half. It’s a low dose and the when taken via skin (i.e., patch) it seems to be much safer. It’s been a miracle for me and several other friends who are going through or have gone through menopause. I am a vegan who eats a healthy whole food, balanced diet. I could not have survived this process of peri-menopause (which I am still going through) without the help of hormones. I’ve also had to cut soy out of my diet completely–soy oils, soy sauce, soy lecithin, everything–because it throws off the balance between the estrogen and progesterone and causes problems. Many women I know have told me that they have felt the HRT has been a “God-send” to them. I feel the same way.

  • DM

    What hormones are we taking about here? Any of the estrogens? Progsterone? Testosterone or any of the other androgens?

  • Lynn

    Someone is trying to use logic to say “there is no evidence” that bio identical hormones are safe. If no one has really studied it, how can same conclusion be drawn for synthetic hormones (such as Premarin and Provera) verses hormones that are bio-identical? Taking Bio-identical hormones helps with sleep, mood swings, depression, hot flashes, BUT if one decides not to take hormones, one could take an antidepressant and sleeping pills to help with symptoms of hot flashes, mood swings, depression and sleep. I’d rather take bio identical hormones, something identical to what my body made, than something synthetic and have quality of life. I am not careless about my health, I am vegan, gluten free, non GMO and eat lots of fruits and vegetables. I exercise regular, do not smoke or drink or use caffeine. Doing my best to live healthfully. I feel so much better taking bio identical hormones that I’m willing to go against the statement “avoid bio-identical hormones” and enjoy the quality of life that is worth it for me.

  • Kathi Richards

    I guess I just believe in letting nature do what it does. No additives here. I’m a vegan, and have been for 13 years. Hot flashes are mild, sleep is off (I have 3 dogs and a husband on the bed with me), moods are always changing (thank goodness or I wouldn’t know happy from sad). HRT is not for me, but then again neither is processed food or supplements of any kind. Why put anything that is processed/artificial into my body that I try to take good care of.

    • Marji

      Good for you but I agree with Lynn. I eat healthy, very healthy, exercise regularly and have been completely miserable with perimenopause since last December when I was 39, I’m not 40. My first doctor put me on Provera to start my cycle again and I hadn’t done enough research to know that it was a synthetic hormone at the time. No thank you. I’m most certainly not myself in the temper dept. or any other aspect of my life. I would rather try something that’s made from nature that makes me feel like me again by putting back in my body what’s missing. I have struggled with a hormone imbalance for almost 20 years and have no kids as part of that. If you can handle all the changes, kudos to you, not everybody can, me being one of them. I also don’t eat processed foods and hate taking any kind of meds to make me feel better.

  • Janet Kirby MD

    ZRT labs is a good company for monitoring bio-identical HRT using their salivary and urinary metabolites testing.