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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Cycle control, hirsutism and fertility treatment in PCOS

Obstetrics and gynaecology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Stop teratogenic exposure before conception

Anti-androgens and some weight-management medicines can harm a pregnancy, while ovulation may return unexpectedly during PCOS treatment even before cycles become regular.

Action: Check pregnancy when relevant, confirm reliable contraception before anti-androgen use, and complete a documented preconception medicine review with appropriate washout before fertility treatment.

Synopsis

Match PCOS treatment to cycle, androgen, metabolic and fertility goals, prescribe safely, and escalate anovulatory infertility without exposing patients to avoidable pregnancy or medicine harm.

  • Agree the dominant goal before treatment: predictable bleeding, contraception, endometrial protection, hirsutism, acne, metabolic health and conception require different choices.
  • Lifestyle support is recommended for all and should improve health without a single mandated diet or exercise plan; symptom medicines can be offered concurrently rather than withheld until weight changes.
  • Combined oral contraception can treat irregular cycles and hirsutism when eligible; choose the lowest effective oestrogen dose and progestogen through UK contraceptive safety guidance rather than assuming one pill suits everyone.
  • When oestrogen is unsuitable or contraception is not wanted, an LNG-IUS, progestogen-only method or periodic oral progestogen can protect the endometrium, but only some options improve androgen symptoms.
  • Metformin is chiefly used for metabolic outcomes and can assist cycle regulation, particularly when BMI is at least 25 kg/m² or combined contraception is unsuitable; titrate slowly and consider vitamin B12 risk.
  • Hirsutism improvement takes at least six months. Combine cosmetic hair removal with hormonal treatment; add a specialist anti-androgen only with effective contraception and careful safety review.
  • The 2023 PCOS guideline recommends letrozole as the preferred pharmacological ovulation-induction option for anovulatory infertility without another factor, but UK use is off-label and belongs in a monitored fertility pathway.
  • Assess semen and consider tubal factors before or alongside ovulation induction; gonadotrophins, ovarian drilling and IVF are escalation options rather than substitutes for a complete couple-based assessment.

    • Key red flags

    New virilisation or rapidly progressive androgenic symptoms during treatment requires diagnostic reassessment rather than automatic dose escalation.

    Chest pain, breathlessness, unilateral leg swelling, new focal neurological symptoms or severe headache while using combined hormonal contraception needs urgent thromboembolic assessment.

    A positive pregnancy test during anti-androgen, retinoid or weight-loss medicine exposure requires prompt specialist medicine and pregnancy advice without abrupt unsafe assumptions.

    Severe abdominal pain, rapid distension, vomiting, oliguria, dyspnoea or rapid weight increase during gonadotrophin or assisted-conception treatment suggests ovarian hyperstimulation and needs urgent fertility-unit contact.

    Heavy or persistent abnormal bleeding despite cycle treatment requires pregnancy testing and structural or endometrial investigation.

    Investigation priorities

    01
    Pregnancy test and contraceptive reviewFirst step

    Prevent fetal exposure before hormonal, anti-androgen or ovulation-induction treatment.

    Management branches

    Cycle and contraceptionChoose endometrial protection by goal

    Spontaneous bleeds are infrequent and pregnancy is not currently desired.

    1. Exclude pregnancy, ask about abnormal bleeding and assess combined-hormonal eligibility, contraception preference and desire for androgen improvement.
    2. Offer an eligible combined pill, LNG-IUS, progestogen-only method or periodic oral progestogen with an explicit bleeding and review plan.
    3. Review tolerability, blood pressure where relevant, bleeding pattern and whether the chosen method still matches pregnancy intention.

    Key medicines

    Combined oral contraceptiveTake one active oral tablet daily using the selected licensed 21-day, 24-day or tailored regimen, with any hormone-free interval defined by that product and contraceptive guidance.Check UK contraceptive eligibility, blood pressure, migraine aura, smoking, venous and arterial thrombosis risk, liver disease and interacting medicines; counsel urgent thromboembolic symptoms.
    MetforminStart 500 mg orally once daily with food, increasing by 500 mg every one to two weeks toward a tolerated divided or modified-release dose, commonly 1.5–2 g daily.Review eGFR, hepatic disease, acute hypoxia or dehydration and contrast procedures; gastrointestinal effects are common, and long-term use can lower vitamin B12.
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    Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • International PCOS recommendations 2023
    • RCOG international PCOS guideline
    • NICE BNF polycystic ovary syndrome
    • Eflornithine cream UK SmPC
    • Medroxyprogesterone acetate UK SmPC

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom