AlternativeZoladex
Goserelin
GnRH agonist
Pre-op endometriosis/fibroid shrinkage; downregulation in IVF.
SC depot
First-line for
- Severe endometriosis (≤6 months)
- Pre-op fibroid shrinkage
- IVF pituitary downregulation
Mechanism
Continuous GnRH stimulation → pituitary desensitisation → hypogonadotrophic hypogonadism.
GnRH agonist phases
- F — Flare (1–2 w)
- S — Suppression (2–3 w)
- A — Add-back HRT if >6 m
Dosing
- Depot
- 3.6 mg SC q28d or 10.8 mg SC q12w
Contraindications
- AbsolutePregnancy, undiagnosed PV bleed, osteoporosis (without add-back)
Side effects
- Menopausal symptoms — flushes, mood, ↓ libido
- BMD loss with prolonged use
- Initial flare
Fetal & maternal notes
- • Use barrier contraception (not contraceptive itself initially).
Key interactions
Hyperglycaemics / antihypertensives
CautionVariable
Clinical pearls
- 💡 Add-back tibolone/HRT if >6 months.
- 💡 DEXA if repeat course.
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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