Fibroids after menopause: the 10-year study that shows how slowly they shrink

Fibroids after menopause: the 10-year study that shows how slowly they shrink

By , co-founder of BotaviveUpdated

A Japanese clinic followed 97 women with large fibroids for ten years after their final period. The fibroids shrank, but slowly. In women with a body mass index under 25, the largest nodule lost 25 percent of its diameter over the decade. In women with a BMI of 25 or higher, it lost 15.7 percent.

Most women with fibroids after menopause hear the same promise: wait, and they will shrink on their own. The promise has a real basis. Fibroid tissue feeds on estrogen and progesterone, and both hormones fall after the final period. The timeline is the part nobody explains. Most of the shrinking happens in the first two years. After that, the curve flattens.

This article explains what happens to fibroids after menopause, why some keep bleeding or growing, how hormone therapy affects them, and how the options compare if you are 47 with a fibroid the size of a tennis ball and trying to decide whether to wait.

Question What the research shows
How common are fibroids by 50? In an ultrasound study of 1,364 women aged 35 to 49, the estimated rate by age 50 was nearly 70 percent for white women and over 80 percent for Black women.
Do fibroids shrink after menopause? Yes, slowly. Over ten years, the largest nodule lost between 15 and 26 percent of its diameter, depending on BMI and nodule count.
When does most of the shrinking happen? In the first two years after the final period. The rate slows from year three onward.
What slows shrinkage? A BMI of 25 or higher, and four or more nodules.
Does HRT make fibroids grow? A review of 17 studies and 1,122 women found conflicting data. Fibroids are not an absolute reason to refuse HRT, but they need periodic checks.
Is bleeding after menopause a fibroid symptom? Never assume so. Any bleeding a year or more after your last period needs a medical evaluation.

What happens to fibroids after menopause

Fibroids are benign tumors of the smooth muscle in the uterine wall. Doctors call them leiomyomas or myomas. They range from the size of a pea to the size of a grapefruit, and most women have more than one.

They are extremely common. A 2003 study from the National Institute of Environmental Health Sciences screened 1,364 randomly selected women aged 35 to 49 with ultrasound. Half of the premenopausal women who had never been told they had fibroids turned out to have them. By age 50, the estimated cumulative rate was nearly 70 percent for white women and more than 80 percent for Black women. The same research group notes that fibroids are the leading reason for hysterectomy in the United States.

Fibroids grow in response to both estrogen and progesterone. During the reproductive years, the ovaries supply a steady stream of both. In perimenopause, estrogen often swings higher than normal before it falls, which is one reason fibroid symptoms sometimes get worse in your mid to late forties instead of better.

After the final period, ovarian output of both hormones drops to a low baseline. Fibroid cells lose their main growth signal, blood flow to the tumor falls, and the tissue slowly degenerates. Some fibroids calcify and harden. Most become smaller and quieter, and many women stop noticing them at all.

Smaller is not the same as gone. In the 10-year Osaka study, every woman started with a fibroid between 5 and 16 centimeters across. Losing a quarter of its diameter still leaves a 10 centimeter fibroid at 7.5 centimeters. Menopause turns most fibroids from a growing problem into a stable one. It rarely makes them disappear.

Why some fibroids after menopause keep causing symptoms

The Osaka researchers measured the largest nodule in each woman every year and looked for the factors that predicted how much it shrank. Two stood out. A third factor comes from outside the study: hormones that reach the uterus from somewhere other than the ovaries.

Body weight. Women with a BMI under 25 saw their largest fibroid shrink 25.0 percent over ten years. Women with a BMI of 25 or higher saw 15.7 percent. After menopause, fat tissue becomes the main source of estrogen in the body, because it converts other hormones into estrogen through an enzyme called aromatase. More fat tissue means more estrogen reaching the uterus, which fits the slower shrinkage the study recorded.

Number of nodules. A single fibroid shrank 26.3 percent on average. Four or more fibroids shrank 15.2 percent. The study also found that women with one or two nodules shrank fastest in the first two years, then slowed. Women with three or more nodules showed no clear early burst at all. If your ultrasound report lists several fibroids, plan on a slower decade.

Hormones from other sources. Menopausal hormone therapy is the obvious one, covered in the next section. Less obvious sources matter too. DHEA supplements convert to estrogen and testosterone in the body. Herbs with estrogen-like activity, such as red clover and dong quai, have not been tested in women with fibroids. If you know you have fibroids, tell your doctor about every supplement you take, including menopause blends.

One rule overrides everything above. A fibroid that grows after menopause, without hormone therapy, is not routine. Most still turn out to be benign. A rare cancer called leiomyosarcoma looks similar on ultrasound, and new growth after the final period is one of the signs that prompts doctors to investigate further. The same goes for bleeding. Fibroids are a common reason for bleeding in perimenopause, but bleeding a year or more after your last period always needs an evaluation, usually an ultrasound to measure the uterine lining and sometimes a biopsy.

Hormone therapy and fibroids: what 17 studies found

This is the question that fills menopause support groups. A woman starts HRT for hot flashes, starts bleeding, and an ultrasound finds fibroids nobody knew about. Another is told hormone therapy could grow her 8 centimeter fibroid, and has to choose between her mental health and her uterus.

A 2019 review from the University of Bologna pulled together every English-language study on hormone therapy in postmenopausal women with fibroids published since 1990. It found 17 studies covering 1,122 women, including nine randomized controlled trials. Most tested transdermal estrogen (nine studies) and medroxyprogesterone acetate, a synthetic progestin, at various doses (ten studies). Five tested tibolone and two tested raloxifene.

The results conflicted. Some studies found fibroids grew on hormone therapy and others found no measurable change. The authors concluded that fibroids respond to HRT but are not an absolute contraindication. Their recommendations were practical: examine women with fibroids periodically while they take hormones, stop treatment if the fibroids grow, and use the lowest progestin dose that protects the uterine lining.

That last point surprises many women. Progesterone is often thought of as the calming, protective hormone, and it does protect the uterine lining when you take estrogen. Fibroid tissue responds to it too. The Bologna review notes that drugs which block progesterone, such as mifepristone and ulipristal acetate, shrink fibroids. So progesterone is not neutral for fibroids, and the dose matters.

Does that make a progesterone prescription for fibroids a mistake? Not always. In perimenopause, a progestin, often delivered through a hormonal IUD, is used to thin the uterine lining and reduce heavy bleeding. It controls the bleeding without shrinking the fibroid. Ask your doctor which goal the prescription serves.

Pro Tip: If you know you have fibroids and plan to start HRT, ask for a pelvic ultrasound before your first prescription. A follow-up scan six to twelve months later has a baseline to compare against, and growth gets caught early.

Waiting, medication or surgery: how the options compare

If you are 52 and your fibroids are quiet, the answer is usually monitoring. The hard decision belongs to women in their mid to late forties whose fibroids cause heavy bleeding, pelvic pressure or pain right now. The average age at the final period in the United States is 51, so a 46-year-old who waits is looking at five or more years of symptoms, followed by the slow shrinkage described above.

Approach Pros Considerations Best for
Watchful waiting No procedure, no side effects. Shrinkage starts after the final period. Shrinkage is slow and partial. Heavy bleeding continues until menopause. Mild symptoms, close to menopause, normal iron levels
Hormonal IUD or progestin Reduces bleeding. Also protects the lining if you later add estrogen. Does not shrink fibroids. Less effective when a fibroid distorts the uterine cavity. Heavy periods with small or medium fibroids
Hormone-blocking medication Oral GnRH antagonist combinations cut bleeding and lower estrogen, which mimics menopause. Bone density limits on long-term use. Symptoms return when you stop. Bridging the final years before menopause
Uterine fibroid embolization Keeps the uterus. Short recovery compared with surgery. Hot flashes or early menopause in some women over 45. The largest fibroids respond less. Women who want to avoid major surgery
Hysterectomy Permanent. Ends bleeding and fibroid symptoms. Major surgery with weeks of recovery. Removing the ovaries too causes immediate surgical menopause. Large or multiple fibroids, severe bleeding, finished with childbearing

The Osaka data gives you a way to think about waiting. If you have a single fibroid and a BMI under 25, menopause will do more of the work. If you have four or more fibroids and a BMI over 25, expect less help from the calendar. That does not make surgery the right call, but it changes what "wait it out" realistically delivers.

Two embolization stories from the same support group show the trade-off from the other side. One woman went into menopause soon after her procedure. Another started having severe hot flashes and night sweats within months. In women in their late forties, the procedure sometimes tips ovaries that were already winding down into menopause. Ask about this risk before you book.

If you keep your ovaries during a hysterectomy, you will not go into surgical menopause, but you lose the period as a signal. Without it, you track menopause by symptoms and, when needed, blood tests.

Know when to seek professional evaluation:

  • Any bleeding or spotting a year or more after your last period
  • A fibroid that grows after menopause when you are not on hormone therapy
  • Periods that soak through a pad or tampon every hour for several hours, or clots larger than a quarter
  • Fatigue, shortness of breath on stairs or a racing heart during heavy bleeding months, all signs of anemia
  • New pelvic pressure, frequent urination or constipation that does not resolve
  • Sudden, severe pelvic pain

Rebuilding iron after fibroid bleeding with Botavive Glow

Heavy bleeding is the fibroid symptom with the longest tail. Each heavy period drains iron, and the body rebuilds its stores slowly. Many women reach their late forties with low ferritin and never connect the exhaustion, hair shedding and cold hands to the bleeding that caused them. Our guide to optimal ferritin levels for women explains which number to ask for.

Botavive Glow provides 14.5 mg of iron per two-capsule serving, about 80 percent of the daily value. Each serving also supplies 120 mg of vitamin C, which helps your gut absorb iron, plus 20 mcg of vitamin D, folate and vitamin B12. Glow does not shrink fibroids or treat anemia. If a blood test shows iron deficiency anemia, your doctor will likely prescribe a higher dose than any daily vitamin provides.

Glow fits women who are still bleeding heavily and want steady daily iron alongside medical care. Once your periods stop, your iron needs drop to 8 mg a day. At that point, check your ferritin with your doctor before you continue any supplement that contains iron.

Frequently asked questions

Can you have fibroids after menopause?

Yes. Fibroids that formed before menopause usually stay, though they shrink. In the 10-year Osaka study, every woman still had a measurable fibroid a decade after her final period. New fibroids forming after menopause are uncommon, and a new or growing mass needs imaging.

Do fibroids shrink after menopause, and how much?

Most do. In women followed for ten years, the largest fibroid lost between 15 and 26 percent of its diameter. The fastest change came in the first two years. Women with a lower BMI and fewer nodules saw the most shrinkage.

Should I worry about fibroids after menopause?

Quiet fibroids that are stable or shrinking rarely need treatment. Two changes do need a doctor: bleeding a year or more after your last period, and a fibroid that grows while you are not on hormone therapy. Both are usually benign, but both need investigation.

Should I have a hysterectomy now or wait for menopause?

It depends on your symptoms, your age and your fibroids. A woman at 50 with manageable periods often waits. A woman at 45 with several large fibroids, severe bleeding and anemia faces years of symptoms before menopause helps, and less help once it arrives. Ask your gynecologist about medication and embolization before you decide on surgery.

Do fibroids cause weight gain or a bigger belly?

Large fibroids enlarge the uterus, and a uterus with several big fibroids pushes the lower abdomen out and sometimes weighs over a pound. That is size, not fat. Fibroids do not change your metabolism. The midlife belly most women notice comes from hormonal fat redistribution, which our article on the menopause belly covers.

Sources

  1. Oue K, Ichimura T, Murakami M, et al., 2024. Postmenopausal shrinkage of uterine myomas: a retrospective study of 97 cases monitored annually for 10 years. Cureus 16(10): e70656. pmc.ncbi.nlm.nih.gov/articles/PMC11445194
  2. Moro E, Degli Esposti E, Borghese G, et al., 2019. The impact of hormonal replacement treatment in postmenopausal women with uterine fibroids: a state-of-the-art review of the literature. Medicina 55(9): 549. pmc.ncbi.nlm.nih.gov/articles/PMC6780684
  3. Baird DD, Dunson DB, Hill MC, Cousins D, Schectman JM, 2003. High cumulative incidence of uterine leiomyoma in black and white women: ultrasound evidence. American Journal of Obstetrics and Gynecology 188(1): 100 to 107. pubmed.ncbi.nlm.nih.gov/12548202

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