Knowing when to start HRT after menopause is important because the benefits and risks of hormone replacement therapy can vary depending on age, and time since onset of menopause. Menopausal hormone replacement therapy (HRT) offers meaningful relief from symptoms of hot flashes, night sweats, fatigue, depression, cognitive dysfunction and vaginal dryness.
The health benefits of HRT are greater for women starting HRT within 10 years of menopausal onset in the 50-59 age group. Health benefits are still present, but not as favorable for women who begin treatment later. This is “The Timing Hypothesis” of Dr. Howard Hodis which says the greatest cardiovascular benefit is obtained by starting hormone replacement (HRT) within the first 10 years of onset of menopause. (1-5)
Drs. Howard Hodis and Wendy Mack Sum it Up
The cardio-protection of estrogen is best described by “The Timing Hypothesis” of Drs. Howard Hodis and Wendy Mack in a series of articles from 2008 to 2022 which point out for women in the 50-60 year age group, shortly after the onset of menopausal hormone decline, all of the RCTs (Randomized Controlled Trials) are in agreement with observational and animal studies. These clearly show a 40-50 percent reduction in cardiovascular disease in 50-60 year old post-menopausal women taking estrogen replacement. However for older women, there is a null effect, meaning no difference from placebo. (1-5).
Understanding when to start HRT can help women have a more informed discussion with their healthcare provider about whether hormone therapy is appropriate and which hormone formula best fits their needs.
What Is the “Window of Opportunity” for Starting HRT?
The window of opportunity refers to the 10 years after onset of menopause as the window for starting hormone therapy. This window offers the most health benefits. Drs. Howard Hodis and Wendy Mack advise starting hormone replacement in the first 10 years after your final menstrual period, or before age 60. (4)
This window of opportunity was demonstrated by the Women’s Health Initiative (WHI) Study, an NIH sponsored randomized trial published in JAMA in 2002 and 2004. The 2002 study caused widespread fear about hormone therapy causing breast cancer, coronary artery disease, blood clots and strokes. However, these irrational and unfounded fears were created by a sensationalistic media. Later data from the 2004 study shows that estrogen (CEE) does not cause breast cancer and is actually protective. Breast cancer mortality was reduced by 44 percent in the estrogen treated group compared to placebo. This is a paradigm shift in our thinking about estrogen.
In 2022, Dr. Isaac Manyonda, Professor of Obstetrics and Gynaecology at St George’s University of London reviewed the 2004 second-arm WHI study using Premarin (CEE) alone, suggesting that estrogen is a breast cancer preventive, compelling a paradigm shift in thinking, writing:
The evidence now compels a paradigm shift from the traditional thinking that estrogen could cause breast cancer to a recognition that it actually prevents the disease, and that when the disease does occur (no preventative intervention achieves a 100% preventative effect), it is often picked up early and mortality is reduced by up to 44%. (12)
In 2011-2012, Dr. Andrea LaCroix and Garnet Anderson reviewed the follow up data for the 2004 estrogen (CEE) only group showing that women in the 50-59 age group starting estrogen (premarin) hormone replacement therapy closer to menopause had better cardiovascular outcomes than women who started later after age 60. (9-10)
For the “younger” age group (age 50-60 yrs), receiving hormone therapy with Premarin-alone provided an astounding 41% reduction in coronary artery disease, 46% reduction in myocardial infarctions, and 27 % reduction in all cause mortality. In addition, there is a 20-30% reduction in breast cancer. When one lumps all the age groups together, the benefit is NULL. However, when one looks at the 50-60 age group, starting hormone replacement immediately after hormone decline of menopause, the benefits are striking. Dr. Andrea LaCroix writes:
Health outcomes were more favorable for younger [age 50-59] compared with older women [over age 60] for CHD [coronary heart disease], total myocardial infarction, colorectal cancer, total mortality, and global index of chronic diseases. (6-10)
When Does Perimenopause Signal It Is Time to Consider HRT?
Early symptoms of perimenopause are irregular cycles, hot flashes, and disrupted sleep. Perimenopause often signals the transition phase leading to menopause. This is a good time to start a conversation with your doctor about treatment options.
Signs and symptoms of perimenopause including worsening insomnia, hot flashes and night sweats may appear months or years before menstrual periods stop completely. Why are these symptoms happening? The perimenopausal transition phase is characterized by anovulation and ovarian failure. This causes fluctuating estrogen levels and absent progesterone. This can affect sleep, mood, and energy well before full menopause takes effect.
At TruemedMD, the mainstay treatment during perimenopause with high estrogen levels and absent progesterone is natural progesterone as a topical cream or oral progesterone capsules. This is a logical treatment which replaces the missing hormone, progesterone. Later on, as estrogen levels stay low, the addition of estrogen to the hormone program is quite useful. Following your menopausal symptoms over time will provide information to make a decision when to start progesterone. Eventually perimenopause leads to full menopause and a complete HRT program is indicated using a formula of all three hormones, estrogen, progesterone and testosterone.
Does Starting HRT Early Protect Heart and Bone Health?
Starting HRT during the window of opportunity prevents cardiovascular disease, maintains bone density and has other health benefits. As mentioned above, benefits are greater when hormone replacement is started within the first 10 years after onset of menopause. This is the “window of opportunity”. Estrogen protects the coronary arteries and vascular tree and supports bone density and bone remodeling.
Bone loss accelerates rapidly in the first few years after menopause, and cardiovascular risk increases as estrogen levels decline. Women who begin therapy earlier in this transition tend to see more health benefits than women who start after age 60, more than a decade past their last menstrual period.
Is There an Age Limit for Starting Hormone Replacement Therapy?
Let us ask the question, does hormone replacement provide a health benefit in the elderly? Yes, there is a health benefit in the elderly as demonstrated in 2024 by Dr. Seo H. Baik in the Journal, Menopause. Dr. Seo Baik compared the use of estrogen monotherapy in women over 65 to women who never used or discontinued use.
Dr. Seo Baik found that estrogen use was associated with almost 20% risk reduction in mortality. Other benefits were: 16% reduction in breast cancer, 13% reduction in lung cancer, 12% reduction in colorectal cancer, and 11% reduction in heart attack. These benefits are seen in women aged 65 to 79 using low-dose transdermal or vaginal estrogen for managing menopausal symptoms like hot flashes and night sweats. So, the answer is yes, there is considerable health benefit, even in the elderly. This means there is no age limit for HRT.
What Symptoms Suggest You Should Start HRT Now?
Menopausal symptoms of persistent hot flashes, night sweats, vaginal dryness, fatigue, cognitive dysfunction and sleep disruption (insomnia) justify starting HRT sooner rather than later. Hot flashes and night sweats are known as vasomotor symptoms and tend to respond well to estrogen treatment. Mood changes, brain fog, and joint aches are also common but less specific, since other conditions, such as an underactive thyroid, can cause them too.
If you are experiencing perimenopausal or menopausal symptoms, we can help. The TruemedMD clinic and our medical director, Jeffrey Dach, MD, will evaluate your symptom pattern, medical history, physical examination and complete laboratory panel. We have a full discussion of treatment options including the different estrogen formulas and types of estrogens used so you understand what you are actually taking. We then devise a treatment program tailored to you with careful follow up to monitor response to treatment, so you are never left on your own.
What Happens If You Wait Too Long to Start HRT?
If you wait past the window of opportunity, you are still a candidate for HRT. However, as mentioned above, benefits are greater when starting early. Why is this the case? The longer we wait, there is more time for estrogen deficiency diseases to appear. These are the chronic degenerative diseases: osteoarthritis, bone loss, cardiovascular disease, type two diabetes, depression, insomnia, fatigue and weight gain.
How Do We Determine the Right Time to Start HRT for You?
Useful parameters are your current age, date of last menstrual period, severity of symptoms, and medical history before recommending a starting hormone replacement therapy. Lab testing including estrogen, progesterone, testosterone, DHEA , LH, and FSH hormone levels are very useful. This list of lab tests is only a subset of a larger more complete laboratory panel.
The decision to begin hormone replacement therapy requires a full evaluation of your medical history, physical examination and laboratory studies. At TruemedMD, we personalize your bioidentical hormone therapy treatment plan, with close follow up.
What Should You Ask Before Starting Hormone Replacement Therapy?
If you are still thinking about when to start HRT, begin a conversation with your doctor. For example, you might ask about the type of hormones being recommended, and how your response will be monitored over time. You might ask about cardiovascular and breast cancer risk. You should ask how your plan will be adjusted if symptoms change or new health issues arise. The answers you receive should be understandable and make sense to you. It might be a good idea to bring a written list of questions to your appointment. This way everything is covered and nothing missed.
Choosing the best time to start hormone replacement therapy after menopause depends on your age, symptoms, quality of life, medical history, laboratory studies and personal preferences. As mentioned above, natural progesterone is used for the menopausal transition, and a full HRT program for completed menopause.
If you are noticing symptoms or wondering whether now is the time to start HRT, we can help. Feel free to reach out to our office to learn more about what we do. We are glad to talk through your concerns, medical history and when to start HRT formula that is right for you.
Frequently Asked Questions
Is it Too Late to Start HRT after Menopause?
No, it is never too late. Benefits depend on your age at starting and how long it’s been since your last period. Health benefits are greatest when starting HRT within 10 years after menopause. However, after 10 years, there are still health benefits, even in the elderly.
Can HRT Help with Perimenopause Symptoms Before Periods Stop?
Yes. Many women start therapy during perimenopause to manage hot flashes, sleep disruption, and mood changes even before full menopause.
What is the Timing Hypothesis for Hormone Therapy?
The timing hypothesis of Dr. Howard Hodis is based on data from the Women’s Health Initiative Study showing starting HRT closer to menopause offers greater benefit in preventing onset of cardiovascular disease, osteoporosis and osteoarthritis compared to starting later years.
How Long Can Someone Safely Stay on HRT Once Started?
Most women will continue hormone replacement as long as they wish. We use safe formulations which continue to provide health benefits over the long term.
Articles with Related Interest:
Estrogen for Osteoporosis Prevention and Treatment
Estrogen Prevents Heart Disease
Estrogen Prevents Heart Disease Part Two
Hormone Replacement in the Elderly, Is There a Benefit?
Errors in Modern Medicine: The Fear of Estrogen
10 Million Women Study: Does HRT Benefit the Elderly?
References:
1) Hodis, Howard N., et al. “Vascular effects of early versus late postmenopausal treatment with estradiol.” New England Journal of Medicine 374.13 (2016): 1221-1231.
2) Hodis, Howard N., and Wendy J. Mack. “A “window of opportunity:” the reduction of coronary heart disease and total mortality with menopausal therapies is age-and time-dependent.” Brain research 1379 (2011): 244-252.
3) Hodis, Howard N., and Wendy J. Mack. “Postmenopausal hormone therapy and cardiovascular disease in perspective.” Clinical obstetrics and gynecology 51.3 (2008): 564-580.
4) Hodis, Howard N., and Wendy J. Mack. “In perspective: estrogen therapy proves to safely and effectively reduce total mortality and coronary heart disease in recently postmenopausal women.” Menopause management 17.2 (2008): 27.
5) In Perspective: Estrogen Therapy Safely and Effectively Reduces Total Mortality and Coronary Heart Disease in Recently Menopausal Women Howard N. Hodis, MD Wendy J. Mack, PhD
6) Manson, JoAnn E., et al. “Menopausal hormone therapy and long-term all-cause and cause-specific mortality: the Women’s Health Initiative randomized trials.” JAMA 318.10 (2017): 927-938.
7) Hodis, Howard N., and P. M. Sarrel. “Menopausal hormone therapy and breast cancer: what is the evidence from randomized trials?.” Climacteric 21.6 (2018): 521-528.
8) Long-term Follow-up Shows Estrogen Alone and Estrogen Plus Progestin Have Opposite Effects on Breast Cancer Incidence in Postmenopausal Women by Rowan Chlebowski, Dec. 13, 2019
9) LaCroix, Andrea Z., et al. “Health outcomes after stopping conjugated equine estrogens among postmenopausal women with prior hysterectomy: a randomized controlled trial.” Jama 305.13 (2011): 1305-1314.
10) Anderson, Garnet L., et al. “Conjugated equine oestrogen and breast cancer incidence and mortality in postmenopausal women with hysterectomy: extended follow-up of the Women’s Health Initiative randomised placebo-controlled trial.” The lancet oncology 13.5 (2012): 476-486.
11) Baik, Seo H., Fitsum Baye, and Clement J. McDonald. “Effects of Hormone Therapy on survival, cancer, cardiovascular and dementia risks in 7 million menopausal women over age 65: a retrospective observational study.” medRxiv (2022): 2022-05.
12) Manyonda, Isaac, et al. “Could Perimenopausal Estrogen Prevent Breast Cancer? Exploring the Differential Effects of Estrogen-Only Versus Combined Hormone Replacement Therapy.” Journal of Clinical Medicine Research 14.1 (2022): 1.
