01Purpose and principlesWhat the treatment does and how it fits into care.
Medical treatment is selected after acute danger, pregnancy and cancer warning features are addressed. Record full blood count, cycle and non-menstrual bleeding, pain, pelvic pressure, examination when indicated and whether imaging or hysteroscopy is needed. Ask whether pregnancy is desired now or later and whether contraception is a benefit, neutral issue or unacceptable. A medicine that provides excellent bleeding control may be the wrong choice if it conflicts with reproductive goals or a major contraindication.
NICE NG88 places the levonorgestrel intrauterine system first for HMB when no pathology is identified, fibroids are smaller than 3 cm without cavity distortion, or adenomyosis is suspected or diagnosed. Examine and sound or scan as clinically needed, exclude pregnancy, assess infection and uterine anatomy and obtain procedure-specific consent. The 52 mg system releases levonorgestrel locally and is licensed for idiopathic menorrhagia for five years. Explain early irregular or prolonged spotting and NICE’s advice to wait at least six cycles for full benefit when safe and acceptable.
Tranexamic acid is non-hormonal and fertility-preserving. It inhibits plasminogen activation and is used only on heavy bleeding days. The UK tablet SmPC dose is 1 g three times daily for up to four days, with a maximum product dose and renal adjustment. It is useful while fibroid investigations or surgery are arranged. Review current thromboembolic disease, important thrombosis history, haematuria and combined hormonal exposure; stop and assess new visual or thrombotic symptoms.
NSAIDs reduce prostaglandin-driven bleeding and dysmenorrhoea and are most useful when both coexist. Mefenamic acid is licensed at 500 mg orally three times daily, starting on the first day of excessive bleeding and continued for the shortest clinically necessary duration. Take with or after food. Avoid in active or recurrent ulcer disease, previous NSAID gastrointestinal bleeding, severe kidney, liver or heart failure, inflammatory bowel disease and aspirin or NSAID hypersensitivity. Stop if diarrhoea, bleeding or renal illness develops and avoid combining NSAIDs.
Combined hormonal contraception suppresses ovulation and stabilises endometrium while providing reversible contraception. A standard low-dose combined pill is taken according to its product schedule, with extended or continuous regimens considered under FSRH guidance to reduce withdrawal bleeds. Measure blood pressure and assess venous and arterial thrombosis, migraine with aura, smoking at 35 or older, postpartum and breastfeeding status, severe obesity with other risks, liver disease, breast cancer and interacting enzyme inducers. It is not suitable for everyone and should not be improvised as high-dose acute haemorrhage treatment.
Cyclical oral progestogens are another NICE option. The cited norethisterone 5 mg SmPC uses 5 mg three times daily for 10 days to arrest dysfunctional uterine bleeding; for prevention it then describes 5 mg twice daily on cycle days 19 to 26 for the next two cycles. Exclude pregnancy. Norethisterone can have oestrogenic metabolites and important thrombotic, arterial and hepatic contraindications. It is not a contraceptive at this treatment dose. Progestogen-only contraception, including injectable or implant methods, may suppress menstruation but can initially cause unpredictable bleeding.
Fibroid anatomy alters response. A cavity-distorting lesion may prevent LNG-IUS placement, and pharmacological efficacy can be limited with larger fibroids. NICE recommends specialist discussion at 3 cm or larger. While definitive care is arranged, tranexamic acid or an NSAID can be used when safe. Specialist options include short-term GnRH agonists before surgery and NICE-approved oral GnRH antagonists with or without add-back therapy for eligible moderate-to-severe fibroid symptoms; these require product-specific pregnancy, bone, cardiovascular, liver and interaction review rather than a generic class dose.
Treat iron deficiency alongside bleeding control. Oral iron choice and schedule follow haemoglobin, ferritin, tolerance and local guidance; intravenous iron is considered when oral therapy fails, absorption is poor, loss is ongoing or rapid replacement is needed. Do not transfuse stable chronic iron deficiency solely to avoid replacement, but use clinical transfusion guidance in severe symptomatic anaemia. Repeat blood count and assess adherence and ongoing loss.
Define non-response before changing treatment: Was the correct dose taken on the correct days? Was the LNG-IUS allowed an adequate adjustment interval? Did side effects prevent use? Has bleeding become intermenstrual or postmenopausal? A treatment failure can reveal missed cavity disease or make procedural care appropriate. Refer when symptoms remain severe, fibroids meet the specialist threshold, anaemia persists, the patient requests a definitive option or fertility planning is complex.
Key points
- Before treatment, establish pregnancy status where relevant, full blood count, bleeding pattern, structural and endometrial risk, fertility goals, contraceptive need, comorbidity and medicine contraindications.
- For HMB with no pathology, fibroids under 3 cm without cavity distortion, or adenomyosis, NICE recommends considering a levonorgestrel intrauterine system first when acceptable.
- A 52 mg LNG-IUS is inserted once after pregnancy exclusion and suitability assessment and is licensed for idiopathic menorrhagia for five years; advise that irregular bleeding is common initially and benefit may take six cycles.
- If the LNG-IUS is declined or unsuitable, NICE options are tranexamic acid, an NSAID, combined hormonal contraception or cyclical oral progestogens; progestogen-only contraception may also suppress menstruation.
- Tranexamic acid is taken only during bleeding: 1 g orally three times daily for up to four days from onset, with renal adjustment and thrombotic safety review.
- Mefenamic acid is 500 mg orally three times daily with or after food from the first day of excessive bleeding, using the shortest necessary course and stopping for diarrhoea or gastrointestinal bleeding.
- Norethisterone 5 mg orally three times daily for 10 days is licensed to arrest dysfunctional bleeding; prevention in the cited SmPC uses 5 mg twice daily on days 19 to 26 for two subsequent cycles.
- Combined hormonal contraception can reduce bleeding and pain while providing contraception, but use an FSRH eligibility assessment for thrombotic, migraine, smoking, blood-pressure, postpartum and interacting-medicine risks.
- For submucosal fibroids discuss hysteroscopic removal; for fibroids at least 3 cm refer for specialist discussion of medicines, GnRH antagonists, embolisation, myomectomy or hysterectomy.
- Review after adequate correct use with bleeding, pain, quality-of-life and haemoglobin outcomes; investigate or escalate if the pattern changes, adherence is confirmed and benefit remains inadequate.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
HMB without cavity distortion, with contraceptive acceptance and no pregnancy, active pelvic infection or unexplained high-risk bleeding supports the preferred NICE option.
Current conception attempts, dislike of hormones or need for treatment only during bleeding makes tranexamic acid or an NSAID attractive when safe.
Dysmenorrhoea accompanying heavy loss increases the value of an NSAID, LNG-IUS or hormonal suppression while adenomyosis and endometriosis are assessed.
Migraine with aura, important thrombosis risk, uncontrolled hypertension or certain postpartum, smoking, liver and cancer contexts excludes combined hormonal contraception.
Device expulsion, cavity distortion or a submucosal fibroid can make apparently adequate medical treatment ineffective and requires structural reassessment.
New intermenstrual or postmenopausal bleeding during therapy cannot be assumed to be a side effect and needs risk-based examination and cavity assessment.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Full blood count and selective iron profileFirst step - Why
- Measure treatment consequence and diagnose iron deficiency requiring replacement.
- Interpretation and limitations
- Blood count is universal for HMB. Ferritin is selected when iron depletion is suspected or response is uncertain; improving haemoglobin does not prove bleeding control.
- 02
Pregnancy and contraceptive eligibility assessment - Why
- Prevent pregnancy exposure and identify contraindications before hormonal or intrauterine treatment.
- Interpretation and limitations
- Use timing, consent and FSRH medical eligibility; a checklist complements rather than replaces blood pressure, history and medicine interaction review.
- 03
Pelvic examination before LNG-IUS - Why
- Assess infection signs, cervix, uterine position and suitability for intrauterine insertion.
- Interpretation and limitations
- Use consent and a chaperone. Cavity distortion or unexplained bleeding may require ultrasound or hysteroscopy before placement.
- 04
Ultrasound or hysteroscopy after non-response - Why
- Identify fibroid, adenomyosis, polyp or endometrial disease that limits medical success.
- Interpretation and limitations
- Hysteroscopy answers cavity questions; transvaginal ultrasound maps myometrium and adnexa. Choose by new pattern rather than ordering both automatically.
- 05
Blood pressure, renal and hepatic review - Why
- Identify combined hormonal, NSAID, tranexamic and progestogen safety modifiers.
- Interpretation and limitations
- Current values, comorbidity and interacting medicines determine eligibility and dose; renal decline particularly affects tranexamic acid and NSAID safety.
- 06
Treatment response measures - Why
- Determine whether the selected medicine achieves the patient’s own bleeding and function goals.
- Interpretation and limitations
- Track flooding, bleeding days, pain, product changes, activity, side effects and haemoglobin; isolated amenorrhoea may be beneficial if expected and accepted.
04Treatment approachPreparation, options, escalation and aftercare.
01Preferred initial treatmentOffer LNG-IUS when anatomy and goals fitFirst stepPreferredThere is no pathology, only small non-distorting fibroids, or adenomyosis, and the patient accepts intrauterine treatment.+
- 1Exclude pregnancy and concerning bleeding, assess pelvic infection and cavity suitability, explain alternatives and obtain consent for insertion with a chaperone.
- 2Insert a licensed 52 mg LNG-IUS using current product and FSRH guidance and explain pain, perforation, expulsion and expected early irregular bleeding.
- 3Review problems promptly and allow up to six cycles for full HMB benefit when bleeding and side effects remain safe and acceptable.
02Alternative treatmentChoose non-hormonal or hormonal therapy by goal and contraindicationAlternativeAn LNG-IUS is declined, unsuitable, expelled or fails despite adequate use.+
- 1Offer tranexamic acid for bleeding-only days or mefenamic acid when pain and bleeding coexist, checking renal, gastrointestinal and thrombotic safety.
- 2Offer combined hormonal contraception or cyclical oral progestogen when reproductive goals and FSRH or product eligibility permit.
- 3Provide exact start, dose, duration and stop symptoms and arrange outcome review rather than open-ended repeat prescribing.
03Fibroid pathwayUse medicines as treatment or bridge according to sizeUltrasound identifies fibroids that may account for heavy bleeding.+
- 1For lesions under 3 cm without cavity distortion, use the standard NICE options and consider hysteroscopic removal when submucosal.
- 2DefinitiveFor fibroids at least 3 cm, refer for specialist discussion and continue tranexamic acid or NSAID when safe while definitive care is organised.
- 3Discuss specialist GnRH treatment, embolisation, myomectomy or hysterectomy with explicit bone, liver, thrombosis, fertility and recurrence implications.
04Non-responseVerify exposure, then investigate and escalateEscalationBleeding, anaemia or functional impact remains unacceptable after an adequate treatment trial.+
- 1Confirm actual dose, timing, adherence, interactions, device position, side effects and whether the patient’s goal changed.
- 2Reassess pregnancy, intermenstrual or postcoital bleeding, endometrial risk, cervix, fibroids, adenomyosis and cavity pathology with targeted testing.
- 3Refer for ablation, hysteroscopic treatment, fibroid procedure or hysterectomy discussion when appropriate, maintaining iron replacement and symptom control.
05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.
Levonorgestrel 52 mg intrauterine system
Insert one 52 mg intrauterine system after pregnancy exclusion and suitability assessment; the cited product is licensed for idiopathic menorrhagia for five years.Exclude pregnancy, active pelvic infection, unexplained high-risk bleeding and important cavity distortion; discuss insertion pain, perforation, expulsion, ovarian cysts and irregular bleeding, and review missing threads or pregnancy symptoms urgently.
Tranexamic acid tablets
Take 1 g orally three times daily from the onset of heavy bleeding for up to four days, with renal dose reduction and the product maximum observed.Avoid active thromboembolic disease and assess important thrombosis history, haematuria and combined hormonal use; stop for visual disturbance or suspected thrombosis and do not use a routine dose in significant renal impairment.
Mefenamic acid
Take 500 mg orally three times daily with or after food, beginning on the first day of excessive bleeding and continuing for the shortest necessary course.Avoid active or recurrent ulcer, gastrointestinal bleeding, inflammatory bowel disease, severe renal, hepatic or cardiac failure and NSAID hypersensitivity; do not combine NSAIDs and stop promptly if diarrhoea or bleeding occurs.
Norethisterone
For licensed dysfunctional bleeding give 5 mg orally three times daily for 10 days; the cited prevention course is 5 mg twice daily on cycle days 19 to 26 for two cycles.Exclude pregnancy and avoid important current or previous venous or arterial thrombosis, significant liver dysfunction and undiagnosed irregular bleeding; it is not contraception and enzyme inducers can reduce exposure.
06Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Review LNG-IUS pain, bleeding, threads and expulsion concerns early, then assess full benefit over six cycles if the initial course remains safe and acceptable.
- For oral treatment document exact bleeding-day use, dose, missed tablets, side effects and interactions before declaring pharmacological failure.
- Repeat full blood count and iron assessment according to baseline deficit and ongoing loss, continuing replacement beyond haemoglobin correction when indicated.
- Check blood pressure and changing thrombosis, migraine, smoking, liver, renal and interacting-medicine status during hormonal or repeated non-hormonal prescribing.
- Escalate new intermenstrual or postmenopausal bleeding, pregnancy symptoms, device-related severe pain, thrombotic symptoms, gastrointestinal bleeding or worsening anaemia.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Preferred is conditional
The LNG-IUS leads NICE treatment only when anatomy, pregnancy plans, acceptability and contraindications fit; shared choice remains essential.
Non-hormonal preserves timing
Tranexamic acid and NSAIDs act during bleeding without providing contraception, which can suit conception attempts or dislike of continuous treatment.
NSAID treats two mechanisms
Prostaglandin inhibition reduces both uterine cramping and some menstrual loss, but gastrointestinal and kidney safety can outweigh that combined benefit.
Large fibroids resist shortcuts
Cavity distortion and bulk can limit device and tablet efficacy, so medication may serve as a bridge rather than definitive care.
Bleeding pattern can transform
Expected early spotting becomes a new diagnostic problem when it persists, starts late, follows menopause or accompanies pain, discharge or anaemia.
08Common pitfallsFrequent interpretation and management errors.
- 01
Calling the LNG-IUS first choice without assessing pregnancy, cavity distortion, infection, consent and reproductive goals.
- 02
Writing tranexamic acid as a continuous daily medicine instead of a time-limited bleeding-day regimen.
- 03
Combining mefenamic acid with another NSAID or continuing after diarrhoea, gastrointestinal bleeding or acute kidney injury.
- 04
Using norethisterone as contraception or prescribing it before assessing unexplained irregular bleeding and thrombosis risk.
- 05
Repeatedly changing tablets without verifying adherence or investigating new intermenstrual, postcoital or postmenopausal bleeding.
- 06
Allowing medical treatment of a large cavity-distorting fibroid to delay appropriate specialist procedural discussion.