What medications cause postmenopausal bleeding?

October 11, 2025 •

4 min read

Over 10% of women in the US report experiencing postmenopausal bleeding at some point, and certain medications are a key contributor to this unexpected symptom. Understanding what medications cause postmenopausal bleeding is crucial for navigating this health concern and determining the best course of action with a healthcare provider.

Quick Summary

Several medications, including hormone replacement therapy (HRT), tamoxifen, blood thinners, certain antidepressants, and herbal supplements, can lead to unscheduled bleeding or spotting after menopause. Any postmenopausal bleeding requires medical evaluation to identify the cause and rule out serious conditions, regardless of medication use. Management may involve adjusting treatment, but it is important to first consult a doctor for diagnosis.

Key Points

Report All Bleeding: Any instance of bleeding after menopause must be reported to a doctor for evaluation to rule out serious conditions.
HRT is a Common Cause: Irregular or expected bleeding is frequent with Hormone Replacement Therapy (HRT), especially during the initial adjustment period.
Tamoxifen Effects: The breast cancer medication Tamoxifen can cause endometrial changes that lead to bleeding, requiring prompt investigation.
Blood Thinners Increase Visibility: Anticoagulant and antiplatelet medications can make any internal bleeding, including genital tract bleeding, more apparent.
Herbal Supplements Are Not Harmless: Certain herbal products with estrogenic or blood-thinning properties can also induce bleeding and should be considered.
Corticosteroids Can Cause Temporary Bleeding: Injected corticosteroids, used for pain, have been linked to transient postmenopausal bleeding.
Evaluation is Key: A medical evaluation, potentially involving an ultrasound or biopsy, is essential to determine the cause of bleeding.
Management Depends on the Cause: The treatment for medication-induced bleeding can involve adjusting the drug's dose or formulation, under medical supervision.

The Link Between Medication and Postmenopausal Bleeding

Any vaginal bleeding that occurs after a woman has not had a menstrual period for 12 consecutive months is considered postmenopausal bleeding. While many causes are possible, the introduction, cessation, or change in dosage of certain medications can directly or indirectly trigger this symptom. A drug's effect can range from influencing hormonal balance to impacting blood clotting, both of which can result in bleeding. It is important to note that while medication may be the cause, any instance of postmenopausal bleeding warrants a thorough medical evaluation to rule out more serious underlying conditions, such as endometrial cancer.

Hormone-Based Therapies

Hormone Replacement Therapy (HRT)

One of the most common pharmaceutical culprits for postmenopausal bleeding is Hormone Replacement Therapy (HRT), or Menopause Hormone Therapy (MHT), which is used to manage menopausal symptoms. The bleeding is often a direct result of the hormonal shifts introduced by the therapy.

Cyclical or Sequential HRT: In this regimen, a progestogen is taken for part of the month, which is designed to result in a predictable, monthly withdrawal bleed. Bleeding is expected here, but if it occurs at unexpected times, it should be evaluated.
Continuous Combined HRT: This therapy combines estrogen and progestogen to prevent monthly bleeding altogether. However, irregular spotting or bleeding is a common side effect in the first few months (up to 6) as the body adjusts. Persistent bleeding beyond this period requires medical investigation.
Estrogen-only HRT: This is typically prescribed for women who have had a hysterectomy. Bleeding is not expected, and if it occurs, it necessitates immediate evaluation to rule out serious issues.

Tamoxifen

Tamoxifen is a selective estrogen receptor modulator (SERM) often used as an adjuvant therapy for hormone-receptor-positive breast cancer. While it acts as an anti-estrogen in breast tissue, it can have estrogen-like effects on the uterine lining, increasing the risk of endometrial proliferation, polyps, and even endometrial cancer. Any vaginal bleeding, spotting, or discharge while on tamoxifen must be reported to a doctor immediately.

Medications Affecting Blood Clotting

Blood Thinners (Anticoagulants and Antiplatelets)

Patients taking medications that prevent blood clots are at a higher risk of bleeding, and this can include the genital tract. These drugs make any internal bleeding, even from minor causes, more noticeable.

Anticoagulants: Medications such as warfarin, apixaban, dabigatran, and heparin can increase the risk of bleeding from any source.
Antiplatelets: Drugs like aspirin and clopidogrel interfere with the action of platelets and can contribute to unexpected bleeding.

Corticosteroids

Some studies have indicated that parenteral (injected) corticosteroids, often used for pain or inflammation, can cause temporary postmenopausal bleeding. The proposed mechanism involves a transient drop in hormones following the treatment, leading to a shedding of the uterine lining.

Other Medications and Supplements

Mental Health Medications

Certain medications prescribed for neuropsychiatric conditions have been linked to abnormal uterine bleeding, although the mechanism is not always fully understood. These include:

SSRIs: Selective serotonin reuptake inhibitors.
Tricyclic antidepressants.
Antipsychotic medications.

Herbal Supplements

Counterintuitively, some over-the-counter herbal supplements used to manage menopausal symptoms can also cause bleeding, as they may contain phytoestrogens or have blood-thinning effects.

Ginseng: Known to have blood-thinning properties and has been linked to vaginal bleeding in menopausal women.
Black Cohosh: A popular herbal remedy for menopausal symptoms, but can affect the uterine lining.
Hop-containing products: Phytoestrogenic properties can lead to endometrial proliferation and bleeding.

When to See a Doctor and What to Expect

Any episode of postmenopausal bleeding, regardless of whether you suspect a medication is the cause, requires prompt medical evaluation by a general practitioner or gynecologist. The diagnosis is based on the specific medication, bleeding pattern, and findings from an examination and diagnostic tests.

The evaluation may include:

A pelvic examination and detailed medical history.
A pelvic ultrasound to measure the thickness of the uterine lining.
An endometrial biopsy or hysteroscopy to take tissue samples for laboratory testing.

Comparison of Medications and Potential Bleeding


Medication Class	Type of Bleeding	Mechanism	Management Considerations
Hormone Replacement Therapy (HRT)	Spotting, irregular bleeding, or withdrawal bleeding	Direct hormonal effect on the uterine lining.	Adjustment of dosage, switching formulations, or monitoring during initial months.
Tamoxifen	Spotting, heavy bleeding	Estrogen-like effect on the uterus, causing hyperplasia or polyps.	Immediate investigation for endometrial pathology; potential surgical removal of growths.
Blood Thinners	Increased visibility and duration of bleeding	Interfere with blood clotting, making existing bleeding worse.	Evaluation to identify the bleeding source; alternative medication if appropriate.
Corticosteroids	Transient, menstruation-like bleeding	Temporary hormonal fluctuations after administration.	Observation, as it may be self-limiting, but requires evaluation to rule out other causes.
Herbal Supplements	Spotting, irregular bleeding	Phytoestrogenic effects or blood-thinning properties.	Discontinuation of supplement; investigation into underlying cause.

Conclusion

While the discovery of postmenopausal bleeding can be alarming, it is often a manageable symptom with a variety of potential causes, including medications. Hormone therapies like HRT and tamoxifen are well-known culprits due to their direct impact on the uterine lining, while blood thinners, certain antidepressants, and even some herbal supplements can also play a role. It is imperative to remember that what medications cause postmenopausal bleeding is only one part of the diagnostic puzzle. The first and most critical step for any woman experiencing this symptom is to consult a healthcare professional for a proper evaluation to determine the precise cause and ensure serious conditions are not overlooked. Treatment will always depend on the specific diagnosis and may involve medication adjustment, watchful waiting, or more targeted interventions.

Frequently Asked Questions

No. While postmenopausal bleeding should always be evaluated by a healthcare professional to rule out malignancy, many other, less serious conditions can cause it, including medication side effects, polyps, or infections.

Bleeding is common for the first 3 to 6 months after starting or changing HRT as the body adjusts to new hormone levels. If bleeding is persistent, unusually heavy, or occurs after the initial adjustment period, a doctor should be consulted.

Yes, some neuropsychiatric agents, such as SSRIs, tricyclic antidepressants, and antipsychotics, have been associated with abnormal uterine bleeding. It is important to discuss this with your prescribing doctor.

If you are taking tamoxifen and experience any vaginal bleeding, spotting, or discharge, you should report it to your doctor immediately. Tamoxifen's effects on the uterus require prompt medical investigation.

Yes. Certain herbal supplements containing phytoestrogens (like hops) or blood-thinning agents (like ginseng) can cause or contribute to vaginal bleeding in postmenopausal women.

The initial step is to contact a healthcare provider for an evaluation. This will likely involve a physical exam, a detailed discussion of your medical history, and may be followed by a pelvic ultrasound to measure the endometrial lining.

Treatment depends on the specific medication and diagnosis. It may involve adjusting the dose or type of medication causing the bleeding. Never change your medication without consulting a doctor first.