ConditionWomen's & pregnancy health
Hormone Therapy Bleeding (Bleeding on HRT)
Hormone therapy bleeding is vaginal bleeding or spotting in women taking menopausal hormone therapy (HRT). On cyclic (sequential) HRT, a monthly withdrawal bleed is expected. On continuous combined HRT, irregular spotting is common in the first 3 to 6 months and usually settles. Bleeding that is heavy, prolonged, starts after 6 months on continuous HRT, or returns after a bleed-free spell needs checking, usually with an ultrasound and sometimes a biopsy, to rule out polyps, hyperplasia or endometrial cancer.
Also called: Breakthrough bleeding on HRT, HRT-related bleeding, unscheduled bleeding on hormone therapy, hormone-induced uterine bleeding
At a glance
- Cyclic HRT
- A regular withdrawal bleed each month (or every 3 months) is expected.
- Continuous combined HRT
- Spotting in the first 3 to 6 months is common and usually settles.
- Needs checking
- Bleeding after 6 months on continuous HRT, heavy or prolonged bleeding, or bleeding after a bleed-free period.
- Common causes
- Hormone adjustment, missed doses, drug interactions, polyps, fibroids, atrophy, hyperplasia.
- Tests
- Transvaginal ultrasound, endometrial biopsy and sometimes hysteroscopy.
When to get help
Call 911 or go to the ER
- Very heavy bleeding soaking a pad an hour for 2 hours, or bleeding with dizziness or fainting
See a doctor within a day or two
- Heavy or prolonged bleeding on HRT, or bleeding with severe pelvic pain
- Bleeding while taking estrogen alone if you still have a uterus
Book a routine appointment
- Bleeding or spotting that continues beyond 6 months of continuous combined HRT
- Bleeding that returns after you had stopped bleeding on continuous HRT
- Withdrawal bleeds on cyclic HRT that become heavier, longer, irregular or happen at the wrong time
- Bleeding after sex while on HRT
- Any postmenopausal bleeding while on tamoxifen
Usually safe to manage at home
- Light, irregular spotting in the first 3 months of starting or changing HRT, while you keep a bleeding diary and follow up as planned
Why HRT can cause bleeding
Estrogen in HRT thickens the endometrium (the lining of the uterus). Women who still have a uterus take a progestogen as well, to protect the lining from overgrowth. How the progestogen is given determines the expected bleeding pattern.
| Regimen | Usually used | Expected bleeding |
|---|---|---|
| Cyclic (sequential) combined HRT | Perimenopause, or within about a year of the last period | A predictable withdrawal bleed after the progestogen phase, usually monthly |
| Long-cycle HRT | Some women wanting fewer bleeds | A bleed about every 3 months |
| Continuous combined HRT | Postmenopause, usually more than 12 months after the last period | No bleeding once settled; spotting common in the first 3 to 6 months |
| Estrogen with hormonal IUD | Any stage | Often light or no bleeding after the first months |
| Estrogen alone | Only after hysterectomy | No uterus, so no uterine bleeding |
| Vaginal estrogen (low dose) | Vaginal dryness | Rarely causes bleeding; bleeding needs checking |
Causes of unscheduled bleeding
- Adjustment period: the lining stabilizing in the first months
- Missed or late doses, or patches falling off
- Too much estrogen relative to progestogen
- Medicine interactions: some anti-seizure drugs, St. John's wort and certain antibiotics can change hormone levels
- Gut upset reducing absorption of tablets
- Endometrial polyps and fibroids
- Vaginal or cervical atrophy causing light bleeding, especially after sex (atrophic vaginitis)
- Cervical polyps or other cervical problems
- Endometrial hyperplasia, a thickened lining that can be precancerous
- Endometrial cancer, uncommon but the main reason persistent bleeding is investigated
- Starting continuous HRT too soon, while the ovaries are still producing some hormones
When bleeding is a warning sign
Doctors usually recommend assessment if:
- bleeding persists beyond 6 months of continuous combined HRT
- bleeding starts after a period of no bleeding on continuous HRT
- cyclic withdrawal bleeds become heavier, longer or occur at unexpected times
- bleeding is heavy or associated with pain
- there are risk factors for endometrial cancer, such as obesity, diabetes, tamoxifen use, unopposed estrogen or Lynch syndrome
Diagnosis
- History and bleeding diary: pattern, HRT type, adherence, other medicines.
- Pelvic examination to look at the vagina and cervix, and cervical screening if due.
- Transvaginal ultrasound: measures endometrial thickness and looks for polyps or fibroids. Interpretation is different for women on cyclic HRT, so the timing within the cycle matters.
- Endometrial biopsy: a small sample taken in the office.
- Hysteroscopy: a camera inside the uterus to look directly at the lining and remove polyps.
Treatment
- No abnormality found and early in treatment: often reassurance and time.
- Adjusting HRT: increasing the progestogen dose, changing the type, switching from continuous to cyclic HRT, or using a levonorgestrel IUD as the progestogen.
- Treating causes: removal of polyps, treatment of atrophy, managing fibroids.
- Hyperplasia: progestogen treatment or surgery depending on the type.
- Cancer: referral for specialist treatment.
Do not stop HRT suddenly without discussing it with your doctor, but do not ignore persistent bleeding.
Other hormone-related bleeding
- Hormonal contraception: breakthrough bleeding is common in the first 3 months of pills, implants, injections and hormonal IUDs.
- Tamoxifen: raises the risk of endometrial polyps and cancer; any bleeding after menopause on tamoxifen needs investigation.
- Testosterone therapy in transgender men: spotting can occur early; persistent bleeding should be assessed.
Frequently asked questions
Is it normal to bleed on HRT?
It can be. On cyclic HRT a monthly withdrawal bleed is expected. On continuous combined HRT, irregular spotting is common in the first 3 to 6 months. Bleeding beyond that time, or bleeding that is heavy or unexpected, should be checked.
How long does breakthrough bleeding last on HRT?
Breakthrough bleeding on continuous combined HRT usually settles within 3 to 6 months as the uterine lining adjusts. If it continues after 6 months, or starts again after stopping, your doctor will usually arrange an ultrasound.
When should I worry about bleeding on HRT?
See a doctor if bleeding continues after 6 months on continuous HRT, returns after a bleed-free spell, is heavy or painful, or if cyclic bleeds change pattern. Get urgent care for very heavy bleeding or bleeding with dizziness.
Can HRT cause endometrial cancer?
Estrogen alone raises the risk of endometrial cancer in women with a uterus, which is why a progestogen is added. Combined HRT taken correctly does not raise this risk significantly. Persistent unexpected bleeding is still investigated to rule it out.
What can be done to stop bleeding on HRT?
Options include giving the body more time, changing the dose or type of progestogen, switching between continuous and cyclic regimens, or using a hormonal IUD. Any underlying cause, such as a polyp, is treated directly.
Sources
This guide was written from current patient and clinical guidance, including:
- The Menopause Society: Hormone therapy position statement
- ACOG: Management of menopausal symptoms (Practice Bulletin)
- NICE: Menopause - diagnosis and management (NG23)
- British Menopause Society: Management of unscheduled bleeding on hormone replacement therapy
- ACOG: The role of transvaginal ultrasonography in evaluating the endometrium of women with postmenopausal bleeding