Bleeding on Hormone Replacement Therapy (HRT)
- Kate Organ
- 2 days ago
- 3 min read
Unscheduled bleeding: what clinicians mean
We often use the term “unscheduled bleeding” to describe bleeding that is not expected for your specific HRT regimen.
Examples include bleeding on a continuous combined regimen that is intended to be bleed free, or bleeding outside the expected withdrawal bleed window on sequential (cyclical) HRT used in the perimenopause.
Unscheduled bleeding is particularly common in the first 6 months after starting HRT and in the first 3 months after a change in dose or preparation.
Perimenopausal and postmenopausal bleeding: why the distinction matters
Perimenopause
In perimenopause, your ovaries may still produce hormones unpredictably. Some cycles may be ovulatory and others not, so bleeding can be irregular even without HRT. HRT can help symptoms, but it can also overlap with an already variable cycle, so spotting and irregular bleeding are more common.
Post menopause
After menopause (often described clinically as 12 months without a natural period), natural cycling should have stopped. With the right regimen, many women become bleed free on HRT. New bleeding, persistent bleeding, or bleeding that starts after you have been stable on HRT may need review and, depending on timing and risk factors, investigation.
Common causes of bleeding on HRT
1) Regimen timing and menopause stage mismatch
A common cause is using a regimen that does not match where you are in the menopause transition.
· Sequential (cyclical) HRT is commonly used when it has been less than 12 months since your last natural period.
· Continuous combined HRT is commonly recommended once you are postmenopausal and want a bleed free regimen, as it provides continuous endometrial protection.
If you are early post menopause and start continuous combined HRT, irregular bleeding can occur while the womb lining adjusts. Or if you have been prescribe continuous combined HRT and you are still having natural ovulatory cycles you may experience irregular bleeding while using HRT.
If you remain on sequential HRT after menopause, you will usually continue to have a predictable withdrawal bleed, which can feel unexpected if you were expecting periods to stop.
2) Variability of hormone delivery and absorption
Different preparations deliver hormones in different ways. Even when used correctly, absorption can vary, particularly with transdermal preparations (patch, gel, spray). Changes in hormone exposure can trigger spotting or breakthrough bleeding, especially after switching product or changing dose.
3) Progesterone and endometrial protection
If you have a uterus and take systemic oestrogen, you need adequate progestogen (progesterone or a synthetic progestogen) to protect the endometrium (womb lining). Unopposed oestrogen can stimulate the lining to thicken and, over time, increase the risk of endometrial hyperplasia and cancer.
The British Menopause Society (BMS) highlights that sequential regimens typically require progestogen for 12 to 14 days per month, while continuous combined regimens require progestogen every day. Shorter duration, missed doses, wrong type of preogesterone or insufficient dosing are associated with more bleeding and reduced endometrial protection.
When bleeding may indicate that your HRT needs optimising
Bleeding can often be managed initially with a structured HRT review and regimen adjustments, particularly when:
· Bleeding occurs within 6 months of starting HRT.
· Bleeding occurs within 3 months of changing the dose or preparation.
· There are no warning signs such as heavy bleeding, bleeding after sex, new pelvic pain, or systemic symptoms.
Common optimisation options a clinician may consider include:
· Confirming the correct regimen type (sequential versus continuous combined) for your menopause stage.
· Reviewing adherence and the timing of progesterone.
· Adjusting the progestogen dose or duration (often the most important lever).
· Changing the type of progestogen
· Adjusting oestrogen dose
Warning signs that should prompt further investigation
Seek medical advice promptly if you have any of the following:
· Heavy bleeding, prolonged bleeding, or bleeding that is getting worse.
· Bleeding after sex.
· New pelvic pain, pressure symptoms, or unexplained bloating.
· Symptoms of anaemia such as fatigue, shortness of breath, or dizziness.
· Bleeding that starts more than 6 months after initiating HRT, or more than 3 months after a change in dose or preparation (especially on continuous combined HRT, which is intended to become bleed free).
Clinicians may arrange a transvaginal ultrasound to assess the endometrium.
The importance of an HRT review
A structured HRT review is central to both symptom control and safety. It helps ensure you are on the right regimen for your menopause stage, that the progesterone component is adequate, and that any new bleeding is assessed appropriately.
References (UK)
1. British Menopause Society (BMS). Management of unscheduled bleeding on hormone replacement therapy (HRT).
2. British Menopause Society (BMS). Progestogens and endometrial protection (April 2023).
3. NICE. Menopause: identification and management (NG23) (updated 7 November 2024).
4. NICE CKS. Menopause: prescribing information, hormone replacement therapy (HRT).
