Endometriosis & Uterine Fibroids

This information is for clinicians managing patients with symptoms of endometriosis and uterine fibroids, in primary and secondary care, across NHS South West London (SWL).

Summary

Recommendations

  • Linzagolix (Yselty®) and relugolix-estradiol-norethisterone (Ryeqo®) are to be initiated by the patient’s specialist gynaecology team. The patient will be prescribed this medicine and monitored by the gynaecology team for a minimum of 6 months i.e. AMBER 2: Initiation by a specialist, stabilisation for a minimum of 6 months, then continuation in primary care under an individual management plan. (SWL Joint Formulary)
  • Transfer of prescribing responsibility is to be communicated to primary care via clinic letter detailing the individual management plan, including hormonal add-back therapy where required.
  • Patients will remain under the care of their specialist gynaecology team, who will undertake reviews every 12 months and retain responsibility for arranging the annual DEXA scan where required with linzagolix (Yselty®) and relugolix-estradiol-norethisterone (Ryeqo®).

Roles and Responsibility

Gynaecology specialist team responsibility

  • Following a shared decision by a gynaecology specialist (doctor or nurse) with the patient, considering benefits and risks, contra-indications and side effects (see Summary of Product Characteristics (SPC)) initiate linzagolix (Yselty®) or relugolix-estradiol-norethisterone (Ryeqo®) for symptoms of endometriosis in adults according to NICE TA1067 and TA1057, or moderate to severe symptoms of uterine fibroids in adults of reproductive age according to NICE TA996 and TA832.
  • Monitor patient at initiation and ensure the patient is clinically stable, prior to transfer of prescribing responsibility to primary care.
  • Complete clinic letter requesting transfer of prescribing responsibility after a minimum of 6 months and once the patient is stabilised, which should include:
    • Indication for therapy, dose.
    • Individual management plan, including details of hormonal add-back therapy where required.
    • Plans for follow up, including when DEXA scan is due.  
    • Any applicable assessment results upon stabilisation on maintenance dose.
    • Details of Gynaecology specialist team for advice/support.
  • Supply at least 4 weeks of linzagolix (Yselty®) or relugolix-estradiol-norethisterone (Ryeqo®), and hormonal add-back therapy where required, at transfer of prescribing.
  • Continue to follow up the patient for further optimisation of endometriosis or uterine fibroid management as clinically indicated.
  • Retain responsibility for the annual DEXA scan where required with linzagolix (Yselty®) and relugolix-estradiol-norethisterone (Ryeqo®).

Primary care responsibility

  • Continue prescribing linzagolix (Yselty®), including hormonal add-back therapy where required, or relugolix-estradiol-norethisterone (Ryeqo®) at the recommended maintenance dose after initiation and stabilisation and following communication from the gynaecology team as above (AMBER 2 on SWL Joint formulary – transfer of care via clinic letter, to include individual management plan).
  • Add linzagolix (Yselty®), and hormonal add-back therapy where required, or relugolix-estradiol-norethisterone (Ryeqo®) to repeat prescriptions and communicate changes with the patient.
  • Review medication and seek gynaecology specialist advice if concerned about:
    • Linzagolix (Yselty):
      • Angioedema or hypersensitivity (stop medication)
      • Pregnancy/breastfeeding (contraindicated)
      • Genital bleeding of unknown aetiology or change in menstrual bleeding
      • Contraindications to add-back therapy
      • Risk factors for osteoporosis
      • Severe hepatic impairment (contraindicated with Child-Pugh C) or signs of liver injury (stop medication if jaundiced or acute liver enzyme abnormalities)
      • Estimated glomerular filtration rate (eGFR) of less than 59 ml/min (contraindicated)
      • Cardiovascular risk, including concomitant medicines known to prolong QT interval
      • Mood disorders or if depression recurs to a serious degree
    • Relugolix/estradiol/norethisterone (Ryeqo®):
      • Angioedema or hypersensitivity (stop medication)
      • Past or present thromboembolic disease eg. DVT, PE or thromboembolic cardiovascular disease eg. myocardial infarction, CVA, IHD (contraindicated)
      • Thrombophilic disorders eg. Factor V Leiden (contraindicated)
      • Pregnancy/breastfeeding (contraindicated)
      • Risk factors for osteoporosis
      • Headaches with focal neurology or migraines with aura (contraindicated)
      • Known or suspected sex-steroid influenced malignancies
      • Present or past liver tumours, or severe hepatic disease with liver function abnormalities (stop medication if jaundiced)
      • Genital bleeding of unknown aetiology, or persistent excessive menstrual bleeding
      • Mood disorders or if depression recurs to a serious degree
      • Sustained clinically significant hypertension
  • The above lists are not exhaustive, and the specialist gynaecology team should be contacted if there are any other concerns.
  • Follow up in primary care at annual medical review, including blood pressure.

Prescribing and monitoring guidance

Linzagolix (Yselty®) 100mg and 200mg oral tablet

  • For symptoms of endometriosis, the recommended dose is 200mg once daily with concomitant hormonal add-back therapy (estradiol 1mg and norethisterone 500 microgram tablet once daily).
  • For symptoms of moderate to severe uterine fibroids, the recommended dose is 200mg once daily with concomitant hormonal add-back therapy (estradiol 1mg and norethisterone 500 microgram tablet once daily). In women where add-back therapy is not recommended or preferred, the recommended dose is 200mg once daily for 6 months, then 100mg once daily.
  • It should preferably be started in the first week of the menstrual cycle and should be taken continuously once daily with or without food.
  • Pregnancy must be ruled out prior to initiating linzagolix (Yselty®).
  • Hormonal contraception must be stopped prior to initiation. Women of childbearing potential at risk of pregnancy should use non-hormonal contraception while on treatment.
  • In patients at risk of osteoporosis, a DEXA scan is recommended prior to starting treatment, and after one year for all women. A DEXA scan should be considered annually thereafter as clinically appropriate.
  • Linzagolix (Yselty®) should be avoided in patients with an eGFR of less than 59 ml/min.
  • The monitoring requirements include baseline blood pressure and at regular reviews.
  • See SPC for further prescribing and monitoring information.

Relugolix 40mg- estradiol 1mg- norethisterone 500 micrograms (Ryeqo®) oral tablet

  • For symptoms of endometriosis and moderate to severe uterine fibroids, the recommended dose is one tablet once daily, at around the same time each day, with or without food. It should be started within 5 days of the onset of menstrual bleeding.
  • Pregnancy must be ruled out prior to initiating relugolix-estradiol-norethisterone (Ryeqo®).
  • Hormonal contraception must be stopped prior to initiation. Women of childbearing potential at risk of pregnancy should use non-hormonal contraception for at least one month after initiation of relugolix-estradiol-norethisterone (Ryeqo®). After at least one month, it provides adequate contraception.
  • In patients at risk of osteoporosis, a DEXA scan is recommended prior to starting treatment, and after one year for all women. A DEXA scan should be considered annually thereafter as clinically appropriate.
  • No dose adjustment is required in patients with mild, moderate, or severe renal impairment.
  • The monitoring requirements include baseline blood pressure and at regular reviews.
  • Discontinuation should be considered when the patient enters menopause.
  • See SPC for further prescribing and monitoring information.

V1: Approved by NHS SWL Integrated Medicines Optimisation Committee August 2026