Subcutaneous implant that, after an initial surge, shuts down sex hormone production. Used in prostate cancer, hormone-dependent breast cancer, and endometriosis.
Regulatory status
Approved (FDA / EMA)
Family
GnRH agonist (long-acting implant)
Scientific evidence
High
Number of findings
1
Where it acts
Sexual and reproductive · Hormones and metabolism
Also known as
goserelin, Zoladex
Regulatory status
FDA (US): Approved (1989, Zoladex) for prostate cancer; later also for advanced breast cancer, endometriosis, and endometrial thinning
EMA (EU): No centralized authorization; authorized through national procedures in the EU and in Spain (Zoladex)
Dose
3.6 mg subcutaneous implant every 28 days; in prostate cancer also 10.8 mg every 12 weeks (FDA/AEMPS label).
Safety
Hot flashes, decreased libido, vaginal dryness or erectile dysfunction, bone loss with prolonged use, mood changes. In prostate cancer, possible initial worsening from the testosterone surge. Contraindicated in pregnancy. Under medical supervision.
Interactions
Caution with drugs that prolong the QT interval.
Differences between women and men
Used in both sexes for different purposes: in men for prostate cancer; in women for premenopausal breast cancer and endometriosis. In young women with breast cancer, adding it to chemotherapy helped preserve ovarian function: more pregnancies at 5 years (23.1% vs 12.2%) in the POEMS study. Contraindicated in pregnancy. View the study →
Effect by goal · level of evidence
Ovarian protection during breast cancer chemotherapy
improvesModerateRCT (AA)in people
×2 pregnancies
In POEMS (218 evaluable premenopausal women), adding goserelin to chemotherapy reduced early menopause and doubled the probability of pregnancy at 5 years (23.1% vs 12.2%; OR 2.34), without worsening survival.
Mimics GnRH. At first it stimulates the pituitary gland (and testosterone or estrogen rises for a few days), but its continuous presence exhausts the receptors and the pituitary stops releasing LH and FSH. The result is a sustained drop in sex hormones, equivalent to a reversible castration.
What the evidence says
In people
Ovarian protection during breast cancer chemotherapy. In POEMS (218 evaluable premenopausal women), adding goserelin to chemotherapy reduced early menopause and doubled the likelihood of pregnancy at 5 years (23.1% vs 12.2%; OR 2.34), without worsening survival. PubMed 30371800