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GnRH receptor antagonist Pregnancy: The label doses males only. §8.1, verbatim: 'The safety and efficacy of ORGOVYX have not been established in females. Based on findings in animals and mechanism of action, ORGOVYX can cause fetal harm and loss of pregnancy when administered to a pregnant female. There are no human data on the use of ORGOVYX in pregnant females to inform the drug-associated risk. In an animal reproduction study, oral administration of relugolix to pregnant rabbits during organogenesis caused embryo-fetal lethality at maternal exposures that were 0.3 times the human exposure at the recommended dose of 120 mg daily based on AUC. Advise patients of the potential risk to the fetus.' §5.3 adds: 'Advise males with female partners of reproductive potential to use effective contraception.' This summary may be incomplete — check the full SPC.

Relugolix

Relugolix is an oral gonadotrophin-releasing hormone (GnRH) receptor antagonist; in women's health it is combined with oestradiol and a progestogen to treat symptoms of uterine fibroids and endometriosis.

Adult dose

Dose: Advanced prostate cancer: a loading dose of 360 mg on the first day of treatment, then 120 mg once daily. §2.1, verbatim: 'Initiate treatment of ORGOVYX with a loading dose of 360 mg on the first day and continue treatment with a 120 mg dose taken orally once daily at approximately the same time each day.'
Route: Oral. §2.1: 'ORGOVYX can be taken with or without food... Instruct patients to swallow tablets whole and not to crush or chew tablets.' §3 lists one presentation only: 'Tablets: 120 mg, light red, almond-shaped, film-coated, and debossed with "R" on one side and "120" on the other side.'
Frequency: Once daily at approximately the same time each day, after the day-1 loading dose. Missed dose, §2.1 verbatim: 'Advise patients to take a missed dose of ORGOVYX as soon as they remember. If the dose was missed by more than 12 hours, patients should not take the missed dose and resume with the next scheduled dose.' Interruption, §2.1 verbatim: 'If treatment with ORGOVYX is interrupted for greater than 7 days, restart ORGOVYX with a loading dose of 360 mg on the first day, and continue with a dose of 120 mg once daily.'
Max: No maximum dose is stated anywhere in the fetched label. The two larger figures it contains are not ceilings and are explained in the notes.
SCOPE — this record covers the page's own stated indication. The indication is therefore kept as a prefix inside the dose field itself, not only in these notes, so a gynaecological reader cannot take the figure unqualified. Nothing in this bundle doses any gynaecological indication: if the page is meant to carry one (relugolix combination therapy for uterine fibroids or endometriosis is a different product, with its own separate entry), it needs its own source bundle. || THE TWO NON-CEILING FIGURES: 360 mg is the day-1 loading dose, repeated only when treatment has been interrupted for more than 7 days; 240 mg once daily is a dose INCREASE required when co-administration with a combined P-gp and strong CYP3A inducer is unavoidable (§2.3). Neither is a maximum. || DOSE MODIFICATION, ORAL P-gp INHIBITORS (§2.2, verbatim): 'Avoid co-administration of ORGOVYX with oral P-gp inhibitors. If co-administration is unavoidable, take ORGOVYX first and separate dosing by at least 6 hours... Monitor patients for increased adverse reactions. Treatment with ORGOVYX may be interrupted for up to two weeks if a short course of treatment with a P-gp inhibitor is required. Resume ORGOVYX after the P-gp inhibitor is discontinued.' || DOSE MODIFICATION, COMBINED P-gp AND STRONG CYP3A INDUCERS (§2.3, verbatim): 'Avoid co-administration of ORGOVYX with combined P-gp and strong CYP3A inducers. If co-administration is unavoidable, increase the ORGOVYX dose to 240 mg once daily. After discontinuation of the combined P-gp and strong CYP3A inducer, resume the recommended ORGOVYX dose of 120 mg once daily.' || DURATION (§2.1, verbatim): 'In patients treated with GnRH receptor agonists and antagonists for prostate cancer, treatment is usually continued upon development of nonmetastatic or metastatic castration-resistant prostate cancer.' || OLDER PATIENTS (§8.5): of the 622 patients who received ORGOVYX in the HERO study, 81% were 65 or older and 35% were 75 or older; 'No overall differences in safety or effectiveness were observed between these subjects and younger subjects', and no dose change is specified. || Not from a UK SPC — UK product information may differ. Verify the whole record, including the UK licensed indication wording and the UK product name, against the UK SPC before publication.

Dose adjustments

Renal

Not stated — no renal-impairment section was retrieved in this bundle and no renal dosing statement appears in any fetched section (§2.1-2.3 give dose modifications only for P-gp inhibitors and for combined P-gp/strong CYP3A inducers). Verify against the full prescribing information and the UK SPC.

Hepatic

Not stated — no hepatic-impairment section was retrieved and no hepatic dosing statement appears in any fetched section. ALT and AST increases are listed among the ≥15% laboratory abnormalities in §6.

Dose independently re-sourced from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Severe hypersensitivity to relugolix or to any of the product components — §4, verbatim: 'ORGOVYX is contraindicated in patients with severe hypersensitivity to relugolix or to any of the product components.'
  • Not a contraindication but an avoidance (§2.2/§7.1): oral P-gp inhibitors — avoid co-administration; if unavoidable, take relugolix first, separate dosing by at least 6 hours and monitor more frequently
  • Not a contraindication but an avoidance (§2.3/§7.1): combined P-gp and strong CYP3A inducers — avoid co-administration; if unavoidable, increase the dose as stated in the notes
  • Not a contraindication but a population limit (§8.1): 'The safety and efficacy of ORGOVYX have not been established in females'; §8.4: 'The safety and efficacy of ORGOVYX in pediatric patients have not been established'

Side effects

  • Most common adverse reactions (≥10%) and laboratory abnormalities (≥15%), §6 verbatim: 'hot flush, glucose increased, triglycerides increased, musculoskeletal pain, hemoglobin decreased, alanine aminotransferase (ALT) increased, fatigue, aspartate aminotransferase (AST) increased, constipation, and diarrhea'
  • QT/QTc interval prolongation — §5.1: 'Androgen deprivation therapy, such as ORGOVYX, may prolong the QT/QTc interval'
  • Hypersensitivity reactions including angioedema — §5.2: 'Hypersensitivity reactions, including pharyngeal edema and other serious cases of angioedema, have been reported' (section truncated at the fetch limit). 'Withhold ORGOVYX in patients who experience symptoms of hypersensitivity. Discontinue ORGOVYX for severe hypersensitivity reactions and manage as clinically indicated'
  • Embryo-fetal toxicity — §5.3: 'ORGOVYX can cause fetal harm. Advise males with female partners of reproductive potential to use effective contraception'

Monitoring

  • ECG and electrolytes — §5.1, verbatim: 'Providers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, or frequent electrolyte abnormalities and in patients taking drugs known to prolong the QT interval. Electrolyte abnormalities should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes'
  • Symptoms of hypersensitivity — withhold for symptoms, discontinue for severe reactions (§5.2)
  • When co-administration with an oral P-gp inhibitor is unavoidable: 'Monitor patients for increased adverse reactions' (§2.2/§7.1)
  • Laboratory abnormalities reported at ≥15% that a prescriber would follow: glucose increased, triglycerides increased, haemoglobin decreased, ALT increased, AST increased (§6)

Clinical monograph

How it works

It competitively blocks pituitary GnRH receptors, rapidly suppressing the release of LH and FSH and thereby lowering ovarian oestradiol production, with the added oestradiol/progestogen offsetting hypo-oestrogenic effects.

Prescribing in practice

  • Even with add-back hormones, treatment can reduce bone mineral density, so duration should be limited and bone health considered, particularly with risk factors for osteoporosis.
  • Because it can restore ovulation and is contraindicated in pregnancy, effective non-hormonal contraception is needed during use.
  • It is contraindicated in undiagnosed abnormal uterine bleeding and in known or suspected hormone-sensitive malignancy.

Monitoring

Assess bone mineral density where prolonged use or osteoporosis risk applies, and reassess the need for continued treatment periodically.

Counselling the patient

  • Take the tablet once daily at about the same time each day.
  • Use a non-hormonal method of contraception while taking this medicine.
  • Report any unexpected or worsening vaginal bleeding.

Evidence & guidelines

Recommended by NICE for heavy menstrual bleeding due to uterine fibroids and for symptomatic endometriosis on the basis of randomised controlled trials.

Reference: NICE TA832; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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