Research Update: Is Hormone Replacement Safe in Menopause?

Research Update: Is Hormone Replacement Safe in Menopause?

Back in 2002, many women stopped taking hormones when the Women’s Health Initiative trial showed they caused an increased risk of breast cancer and gave no protection against heart disease. This trial has been dissected and studied in many different ways since it was first published. There have been a number of scientists who have called out major issues with this study starting when it was first published.

Nevertheless, it led to significant amounts of women dropping out of hormone replacement therapy altogether.

Now we have NEW data from the Women’s Health Initiative trial! This information is specific to women who were 50-59 at the time they enrolled. There were 2 categories of women in the trial:

  • Women with a uterus were given conjugated equine estrogen (CEE) and medroxyprogesterone (MPA). The trade name for this medication is PremPro and contains Premarin and
  • Women without a uterus (because of hysterectomy) were given CEE The trade name is Premarin.

Here’s what the most recent analysis reveals. First, for women given CEE alone:

  • The risks of taking CEE are 20%-40% higher for older women compared with those aged 50-59 when starting hormone
  • 7 years of CEE treatment yields global benefits that exceed the risks in women aged 50-59 who were followed for 18
  • CEE specifically reduced the risk of breast cancer, heart disease, and total mortality without increasing the risk of stroke or other global

For women given CEE + MPA, the risks were slightly different:

  • There was no significant global risk of taking CEE + MPA for an average of 6 years.
  • Breast cancer risk was elevated in this

What does all of this mean?

  • The long term health benefits of CEE given alone to women post-hysterectomy in the age range of 50-59 outweigh the
  • However, the latest data continues to point toward harm when MPA is added to CEE, even in women aged 50-59. Specifically, the synthetic progesterone increases breast cancer

This data points out several things that we have been saying about hormone replacement therapy for 30 years.

The Women’s Health Initiative enrolled postmenopausal women with an average age of 65 years. We have advocated starting hormone replacement therapy in women 50-55 and this data supports that recommendation.

We do not advocate using synthetic hormones for hormone replacement. Provera is a synthetically derived chemical that is called progesterone but is not. Progesterone itself

is bioidentical. Premarin is bioidentical, but only for horses! Estradiol, estrone and estriol are bioidentical for human females. We only advocate for bioidentical hormone replacement strategies.

Start hormone replacements early in menopause (or perimenopause) and reap the youthful benefits of staying on them.

Hormone replacement therapy reduces the risks of heart disease, stroke, breast cancer and mortality for 18 years if taken at least 7 years. Even starting hormone replacement at age 59 reduces these rates for women until they are 77 years old.

I started teaching the above benefits of hormone replacement therapy to medical students in 1990 because the data was available way back then. This study confirms that data. Stay away from Provera and synthetic hormones and advocate for bioidentical forms of hormone replacement therapy when discussing this issue with your doctor.

This study specifically looked at treatment with synthetic hormones, but we have so many other tools available to optimize hormonal levels with age. The approach we take looks like this:

Comprehensive hormone testing to determine your unique needs

Bioidentical natural hormone replacement (not synthetic like those used in the trial discussed here) if appropriate that are individualized for you

Natural therapies like herbs and nutrition to support hormone metabolism

Lifestyle changes to set you up for lifelong hormonal health


If you have any questions about hormones or hormone replacement, please reach out to me to book a health coaching consult at In an hour, I can tell you what you need to ask your doctor or lead you to a doctor that will work with you on safe and effective bioidentical hormone replacement! Send me an email to for more information and I’ll send you some other articles to read on this topic.


#hormonehealth #bioidenticalhormonereplacement #womenshealth #hormoneoptimization



Prentice RL, Aragaki AK, Chlebowski RT et al. Randomized Trial Evaluation of the Benefits and Risks of Menopausal Hormone Therapy Among Women 50-59 Years of Age. Am J Epidemiol. 2021; 190: 365-375. [link]

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