GnRH Agonist (Pituitary Desensitiser) Pregnancy: CONTRAINDICATED — risk of fetal harm; effective contraception required during treatment (non-hormonal barrier methods preferred)

Leuprorelin Acetate

Brand names: Prostap, Lupron (US)

Adult dose

Dose: 3.75 mg IM monthly or 11.25 mg IM every 3 months

Route: Intramuscular injection (depot)

Frequency: Monthly or 3-monthly depot

Max: 11.25 mg per 3-month depot

Endometriosis, uterine fibroids, IVF down-regulation; initial flare for 1-2 weeks due to initial LH/FSH surge before suppression; HRT add-back therapy required if >6 months use

Paediatric dose

Dose: Precocious puberty: 0.2–0.3 mg/kg IM (minimum 7.5 mg) mg/kg

Route: Intramuscular

Frequency: Monthly

Max: 15 mg/month

Paediatric indication: central precocious puberty — specialist prescribing only

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Paediatric indication: central precocious puberty — specialist prescribing only

Clinical pearls

Initial LH/FSH flare occurs before pituitary desensitisation (first 1-2 weeks) — can temporarily worsen endometriosis pain or cause fibroid swelling; counsel patients and consider short-course NSAID cover
Bone density loss: measurable after 3-6 months; largely reversible after stopping; add-back HRT protects against BMD loss during extended treatment without compromising efficacy — ESHRE endometriosis guideline endorses add-back from the outset
IVF long-protocol: leuprorelin used for pituitary down-regulation before gonadotrophin stimulation — starting day 21 of preceding cycle; check E2 <200 pmol/L and endometrial lining thin before stimulation
Fibroids pre-op: reduces size by 30-50% and corrects anaemia over 3 months; should not exceed 3-6 months — rebound growth occurs after stopping
GnRH agonist vs GnRH antagonist (elagolix/relugolix): agonists cause initial flare; antagonists provide immediate suppression without flare — clinical relevance in pain management

Contraindications

Undiagnosed abnormal vaginal bleeding
Pregnancy (may harm fetus)
Breastfeeding
Known hypersensitivity to GnRH agonists

Side effects

Menopausal symptoms (hot flushes, sweats, vaginal dryness)
Bone mineral density loss (>6 months use)
Initial flare (worsening of endometriosis/fibroid pain in first 1-2 weeks)
Headache
Mood changes
Depression

Interactions

Add-back HRT (low-dose oestrogen + progestogen) — recommended if >6 months to protect bone density and improve menopausal symptoms
Anticoagulants — monitor; depot formulations may affect absorption if injection technique varies

Monitoring

BMD (DEXA if >6 months treatment)
Oestradiol levels (confirm suppression)
Symptom response
Injection site reactions

Reference: BNFc; BNF 90; ESHRE Endometriosis Guideline (2022); RCOG Fibroid Guidelines; NICE NG126; SPC Prostap; Strowitzki et al. Fertil Steril 2010. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators