HRT and Endometrial Cancer Risk: What Raises It, What Lowers It, and What to Check

Some HRT raises endometrial cancer risk and some doesn’t — it comes down to the regimen. The clearest higher-risk setup is systemic estrogen with no progestogen when you still have a uterus. Current U.S. estrogen labeling reports that women using unopposed systemic estrogen who have a uterus have an endometrial cancer risk about 2 to 12 times higher than non-users, rising to roughly 15 to 24 times higher after five to ten or more years of use. Add adequate protection and that excess risk largely disappears. [1][2]

If you don’t have a uterus, there’s no endometrium to protect, so the unopposed-estrogen risk mostly doesn’t apply — and a progestogen usually isn’t needed. If you do have a uterus and use systemic estrogen, you need protection. This single fact reorganizes the whole conversation.

The clearest higher-risk setup is systemic estrogen with no protection when you have a uterus. Combined regimens, a hormonal IUD, a progestogen-free combination, low-dose vaginal estrogen, no uterus, and compounded products are all different situations — they are not interchangeable. We assembled these U.S.-relevant setups from current FDA labels, clinical guidance, and peer-reviewed evidence.

Want to match your exact setup to the right next step?Answer a few quick questions and we’ll point you to the right kind of care for your anatomy, symptoms, and route — and flag when you should start with an in-person clinician.

No. A patch, gel, and spray are all systemicestrogen, meaning the hormone reaches your whole body — so if you have a uterus, you still need endometrial protection. “Systemic” and “oral” are not the same thing; switching from a pill to a patch changes the delivery, not the need to balance estrogen at the lining.

Write these down before your visit

The exact name of your estrogen, its route (pill, patch, gel, spray), its strength, how often you use it, whether it’s meant for whole-body or vaginal symptoms, and — if you have a uterus — the name and schedule of your progestogen. Then ask: “Is my estrogen systemic, and what exactly is protecting my uterine lining while I use it?”

There’s no single percentage that fits every regimen, but the direction is clear and reassuring: a progestogen counters estrogen’s effect on the lining and generally removes the excess risk of unopposed estrogen. In the Women’s Health Initiative trial of one specific daily regimen — 0.625 mg conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate — there were fewer endometrial cancers than with placebo (66 vs 95 cases; about 0.06% vs 0.10% per year). [4]

The WHI numbers in plain terms

Over a median 5.6 years of treatment and about 13 years of follow-up: roughly a 35% relative reduction, and an absolute difference of about 0.04 percentage points per year. The protective regimen didn’t just hold the line — it came out slightly below the no-hormone group.

The fine print — because it matters

• Those numbers describe one regimen in one study. They don’t prove every combination, every dose, or every product performs identically.
• How you take it counts. Repeatedly missing doses, or stopping the progestogen while continuing systemic estrogen, can reduce the protection. Ask your prescriber how to handle missed doses for your exact regimen.
• “I take progesterone” isn’t enough detail. To know whether your setup is reassuring, a clinician needs the exact medication, route, dose, whether it’s daily or cyclical, and the estrogen it’s balancing. See also: micronized progesterone side effects.

Continuous combined HRT — estrogen and a progestogen taken together every day — has the most direct evidence for avoiding excess endometrial risk. Cyclical (sequential) HRT, where the progestogen is taken during part of each cycle, is protective when done correctly but depends more on the exact schedule and duration.

One nuance worth knowing: with cyclical HRT, too few progestogen days a month leaves risk elevated, and using a sequential regimen beyond about five years may carry a small extra endometrial risk. [3] The questions that actually tell you whether a schedule is reassuring: What exact progestogen? How many days a month? How long have I been on it? What bleeding is expected? See also: progesterone side effects in menopause.

This is the setup to scrutinize. Compounded progesterone — made to order by a pharmacy as a cream, troche, or lozenge — has documented concerns about whether it actually protects the endometrium. Compounded transdermal progesterone has variable absorption and may not deliver a protective dose, and a published case series reported endometrial cancers in women using compounded “bioidentical” HRT. [3][10]

The options with the clearest evidence for endometrial protection are FDA-approved systemic progestogens (like oral micronized progesterone or medroxyprogesterone), an FDA-approved combined product, or — used off-label in the U.S. — a 52 mg levonorgestrel IUD. [3][5]

If a compounded program is what you’re using or being offered

Don’t let the part that protects your uterus be the compounded part without asking hard questions — the exact ingredients, the route, the dose, the pharmacy, and what evidence supports the protection plan. If that conversation isn’t reassuring, that’s your signal to get a second opinion.

Low-dose vaginal estrogen is a different, lower-risk category than systemic estrogen. It treats vaginal and urinary symptoms with much less estrogen reaching the bloodstream, and it hasn’t been shown to raise endometrial cancer risk. Across 20 randomized trials involving 2,983 women, reported endometrial cancer and hyperplasia rates were about 0.03% and 0.4%. A progestogen generally isn’t recommended alongside it. [7][8]

No. Monitoring can only look for changes after they start — it can’t preventthe overgrowth that unopposed estrogen causes, and it isn’t a substitute for a clinician-directed protection plan. There’s also no routine screening test for endometrial cancer in average-risk women without symptoms, and a Pap test screens for cervical cancer, not endometrial cancer. [17]

Simply dropping your endometrial protection while staying on systemic estrogen is not a safe do-it-yourself fix if you have a uterus. But you’re not stuck — a clinician can often switch the progestogen, the route, the schedule, or the whole approach. Progestogen side effects (mood changes, bloating, fatigue, breast tenderness) are a common reason women want to quit, and they deserve a real solution.

Bring to your visit

Exactly which side effect you get, when it hits after each dose, what you’ve already tried, your current dose and schedule, whether you need estrogen for whole-body or just local symptoms, and any bleeding.

Struggling with your current regimen?We’ll help point you to the right kind of care so the conversation gets to a real fix faster — without you having to guess at the medicine.

Bleeding after menopause is the single most important symptom to get evaluated, because about 90% of endometrial cancers show up as postmenopausal bleeding. [18] The good news: most bleeding isn’t cancer — about 9% of women evaluated for postmenopausal bleeding are diagnosed with endometrial cancer, and lining thinning (atrophy) is the most common cause. [19]

What changed in April 2026 — why some older pages are now out of date

ACOG updated its guidance on evaluating postmenopausal bleeding. For most patients, it now recommends both a transvaginal ultrasound and an endometrial biopsy at the first evaluation — instead of the older approach of ultrasound alone when the lining measured 4 mm or less. [20] The reason: endometrial cancer has been rising, and ultrasound alone can miss an estimated 5 to 12% of cancers at first check.

Ultrasound without a biopsy may still be reasonable for a select patient with a single bleeding episode, a fully visualized lining no thicker than 4 mm, no major risk factors, and prompt access to care. [20] If your last workup was ultrasound-only, this is worth knowing.

In November 2025 the FDA began removing several risk statements from the boxed warnings on menopause hormone products — but it deliberately kept the boxed warning about endometrial cancer for systemic estrogen-alone products used by women with a uterus. [21][22][23]

Read the change carefully: even while pulling back warnings it considered overstated, the FDA left this onein place. That’s not a loophole — it’s a signal that the estrogen-and-the-lining risk is the one regulators still want front and center. If you have a uterus and use systemic estrogen, you still need protection.

HRT is only one piece of endometrial cancer risk. Age, extra body weight, diabetes, PCOS, never having been pregnant, certain inherited syndromes, and tamoxifen all factor in. Body weight is one of the biggest: one large analysis found women who are overweight had about 1.4 times the odds, and women with obesity about 3.3 times the odds, compared with women at a normal weight — because fat tissue itself makes estrogen. [24]

Yes — unopposed estrogen can cause endometrial hyperplasia, meaning the lining overgrows. The milder form is not the same as cancer and rarely progresses, but it needs a clinician to diagnose and manage. Endometrial hyperplasia without atypia has a low chance of becoming cancer — fewer than 5 in 100 women develop endometrial cancer over 20 years, and roughly 7 to 8 in 10 cases regress without treatment. [25]

A history of hyperplasia, atypical hyperplasia/EIN, or endometrial cancer moves this out of ordinary online-HRT territory and into individualized specialist care. The answer depends on your exact pathology, stage, prior treatment, remaining anatomy, how long ago it was, your symptoms, and whether the therapy would be systemic or local — which is why a general page (or a general telehealth intake) can’t and shouldn’t decide it.

Questions for your gynecologist or oncology team

1. What exactly was my pathology and stage?
2. Do I still have a uterus?
3. Is the symptom I want treated local (vaginal) or whole-body?
4. What non-hormonal options make sense for me?
5. Would low-dose local treatment be considered differently from systemic HRT?
6. Who coordinates my follow-up?

If this is you, start with a gynecologist or gynecologic oncologist — not a generic provider match.

A trustworthy provider confirms whether you have a uterus, tells you plainly whether your medications are FDA-approved or compounded, spells out exactly what protects your lining, explains what bleeding to report and to whom, and refers complex histories to in-person care. Labels like “bioidentical,” “natural,” or “personalized” don’t, on their own, establish FDA approval, manufacturing consistency, or adequate endometrial protection.

Ten questions to ask before you pay

1. Is my estrogen systemic or low-dose local?
2. How did you confirm whether I still have a uterus?
3. What exactly protects my uterine lining?
4. Is each medication FDA-approved or compounded?
5. Why does this progestogen route and schedule fit my estrogen?
6. What happens if I can’t tolerate it?
7. What bleeding should I report, and to whom?
8. Can your service order or coordinate an endometrial evaluation?
9. What history would make you refer me to in-person care?
10. What costs are not included if I need extra evaluation?

Wondering if online care even makes sense for your situation? Our tool matches your symptoms, anatomy, and history to the right kind of care — and flags when you should begin with an in-person clinician.

What we verified

• The FDA’s November 2025 and February 2026 label changes — including that the endometrial-cancer boxed warning was kept for systemic estrogen-alone products
• ACOG’s guidance that adding a progestogen lowers the risk from estrogen-only therapy
• ACOG’s April 2026 update on evaluating postmenopausal bleeding
• The exact Women’s Health Initiative combined-therapy regimen and its reported endometrial cancer numbers
• The current U.S. label status of Mirena, Femring, Estring, and DUAVEE
• Current menopause-society and cancer-organization guidance on compounded hormones, vaginal estrogen, hyperplasia, and risk factors

What we did not verify (and can’t)

Whether your specific regimen is right for you · whether a specific dose protects your lining · the cause of any bleeding · your personal cancer risk · how any individual provider would handle your case.

Last verified: July 14, 2026 · Written by The HRT Index Editorial Team · Independent editorial research, not reviewed by a clinician · The HRT Index Verification Standard

Still deciding?

Still not sure which HRT program is right for you?Take our free matching quiz — it takes about 90 seconds. It helps you find the care pathway that fits your situation, and it flags when online care isn’t the right starting point. It doesn’t diagnose bleeding, calculate cancer risk, or replace a clinician.

1. ACOG. Hormone Therapy for Menopause (patient FAQ) — estrogen-alone therapy thickens the uterine lining and increases endometrial cancer risk; adding progestin decreases that risk. acog.org. Accessed July 2026.
2. U.S. Food and Drug Administration. Class labeling for systemic estrogen products (boxed warning, “Endometrial Cancer”) — reported risk about 2–12× non-users; 15–24× after 5–10+ years; persistence after discontinuation. DailyMed. Accessed July 2026.
3. British Menopause Society. Tools for Clinicians: Progestogens and Endometrial Protection (May 2026) — progestogen duration; 52 mg levonorgestrel IUS; combined HRT after ablation; compounded transdermal progesterone concerns. thebms.org.uk. Accessed July 2026.
4. Chlebowski RT, Anderson GL, Sarto GE, et al. Continuous Combined Estrogen Plus Progestin and Endometrial Cancer: The Women’s Health Initiative Randomized Trial. J Natl Cancer Inst. 2016;108(3):djv350. PMID 26668177.
5. Mirena (levonorgestrel-releasing intrauterine system) U.S. Prescribing Information — indicated for contraception and heavy menstrual bleeding; no menopausal-HRT/endometrial-protection indication. Bayer / DailyMed. Accessed July 2026.
6. DUAVEE (conjugated estrogens/bazedoxifene) U.S. Prescribing Information — “the bazedoxifene component reduces the risk of endometrial hyperplasia that can occur with the conjugated estrogens component.” Pfizer / DailyMed. Accessed July 2026.
7. Constantine GD, et al. Endometrial safety of low-dose vaginal estrogens in menopausal women: a systematic review. Menopause. 2019;26(7):800–807. PMC6636806.
8. The Menopause Society. Hormone therapy guidance — a progestogen is not recommended with low-dose vaginal estrogen. menopause.org. Accessed July 2026.
9. U.S. FDA — systemic estrogen-alone therapy is typically used in women without a uterus (after hysterectomy). DailyMed. Accessed July 2026.
10. Eden JA, et al. Case series of endometrial cancers in women using compounded “bioidentical” hormone therapy. (Case report evidence, not a class-wide incidence.) PubMed. Accessed July 2026.
11. U.S. FDA. Compounding and the FDA: Questions and Answers — compounded drugs are not FDA-approved; FDA does not verify their safety, effectiveness, or quality before marketing. fda.gov. Accessed July 2026.
12. ACOG. Postmenopausal Estrogen Therapy: Route of Administration and Risk of Venous Thromboembolism (Committee Opinion) — transdermal estrogen associated with lower VTE risk than oral. acog.org. Accessed July 2026.
13. McBane SE, et al. Analysis of compounded hormone products — variability in active-ingredient content. PubMed PMID 31453957. Accessed July 2026.
14. The Menopause Society — compounded hormones not recommended for menopause symptoms when FDA-approved options exist. menopause.org. Accessed July 2026.
15. Estring (estradiol vaginal ring) U.S. Prescribing Information — low-dose local product; systemic absorption generally lower than systemic products. DailyMed. Accessed July 2026.
16. Femring (estradiol acetate vaginal ring) U.S. Prescribing Information — systemic ring for moderate-to-severe vasomotor symptoms; carries the systemic boxed warning. DailyMed. Accessed July 2026.
17. American Cancer Society. Can Endometrial Cancer Be Found Early? — no routine screening test for average-risk women; Pap tests are not effective endometrial cancer screening. cancer.org. Accessed July 2026.
18. ACOG — approximately 90% of endometrial cancers present with postmenopausal bleeding. acog.org. Accessed July 2026.
19. National Cancer Institute. For Postmenopausal Bleeding, Prompt Follow-up Is Advised — roughly 9% of women with postmenopausal bleeding are diagnosed with endometrial cancer. cancer.gov. Accessed July 2026.
20. ACOG. Updated Guidance Regarding the Role of Transvaginal Ultrasonography in Evaluating the Endometrium of Individuals With Postmenopausal Bleeding (Clinical Practice Update, April 2026). Obstet Gynecol. 2026.
21. U.S. FDA / HHS. HHS Advances Women’s Health, Removes Misleading FDA Warnings on Hormone Replacement Therapy (Nov 10, 2025) — endometrial-cancer boxed warning for systemic estrogen-alone products NOT removed. fda.gov / hhs.gov.
22. U.S. FDA. FDA Approves Labeling Changes to Menopausal Hormone Therapy Products (Feb 12, 2026) — first batch of six products. fda.gov.
23. Society of Gynecologic Oncology. Statement on FDA boxed-warning changes — endometrial-cancer warning remains for systemic estrogen-alone therapy in women with a uterus. sgo.org (Nov 2025). Accessed July 2026.
24. Meta-analysis of body mass index and endometrial cancer — odds ratios ~1.43 (overweight) and ~3.33 (obesity) versus normal weight. PubMed PMID 26026348. Accessed July 2026.
25. Royal College of Obstetricians and Gynaecologists. Endometrial Hyperplasia (patient information) — fewer than 5 in 100 women with hyperplasia without atypia develop endometrial cancer over 20 years. rcog.org.uk. Accessed July 2026.