FDA Approves Zoladex (goserelin) for Multiple Indications Including Prostate Cancer and Endometriosis

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FDA Published May 12, 2026 Medically reviewed May 12, 2026 DOI ↗ By Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

Key Takeaway

Consider Zoladex for hormonal therapy in prostate cancer, endometriosis, endometrial thinning, and advanced breast cancer with dosing every 28 days.

The FDA has approved Zoladex (goserelin), a gonadotropin-releasing hormone (GnRH) agonist, for several indications including prostate cancer, endometriosis, endometrial thinning, and advanced breast cancer. For stage B2-C prostatic carcinoma, Zoladex is indicated in combination with flutamide, starting 8 weeks prior to radiation therapy and continuing during radiation. It is also approved for palliative treatment of advanced prostate cancer. In endometriosis, Zoladex is indicated for pain relief and reduction of lesions, with a recommended treatment duration of 6 months. As an endometrial-thinning agent prior to endometrial ablation for dysfunctional uterine bleeding, one or two depots may be given. For advanced breast cancer in pre- and perimenopausal women, Zoladex provides palliative treatment. The approval provides clinicians with a hormonal therapy option across these conditions, with dosing every 28 days via subcutaneous injection.

＋ Clinical Details (Mechanism · Dosing · Trial Data · Warnings)

Mechanism of Action

Zoladex is a gonadotropin-releasing hormone (GnRH) agonist. Chronic administration results in suppression of pituitary gonadotropin secretion, leading to decreased serum testosterone in males and estradiol in females.

Indication & Patient Population

Zoladex is indicated for: (1) use in combination with flutamide for management of locally confined stage T2b-T4 (stage B2-C) carcinoma of the prostate; (2) palliative treatment of advanced carcinoma of the prostate; (3) management of endometriosis (including pain relief and reduction of lesions) in women 18 years and older for 6 months; (4) use as an endometrial-thinning agent prior to endometrial ablation for dysfunctional uterine bleeding; (5) palliative treatment of advanced breast cancer in pre- and perimenopausal women.

Dosing & Administration

Zoladex 3.6 mg is administered subcutaneously every 28 days into the anterior abdominal wall below the navel line. For stage B2-C prostatic carcinoma, treatment starts 8 weeks prior to radiotherapy and continues during radiotherapy; either a 10.8 mg depot at 28 days after the first 3.6 mg depot or four 3.6 mg depots at 28-day intervals may be used. For advanced prostate cancer and breast cancer, long-term administration is intended unless clinically inappropriate. For endometriosis, recommended duration is 6 months; retreatment is not recommended. For endometrial thinning, one or two depots (four weeks apart) are given, with surgery at 4 weeks after one depot or within 2-4 weeks after the second depot. No dosage adjustment is needed for renal or hepatic impairment.

Key Clinical Trial Data

Trial data not available in label.

Warnings & Contraindications

Not reported in label.

Place in Therapy

Zoladex provides a GnRH agonist option for hormonal suppression in prostate cancer, endometriosis, endometrial thinning, and advanced breast cancer. Its use in combination with flutamide for locally confined prostate cancer and as monotherapy for advanced disease offers flexibility. For endometriosis, the 6-month duration limits long-term use, and retreatment is not recommended due to lack of safety data. The addition of hormone replacement therapy may reduce bone mineral loss and vasomotor symptoms during endometriosis treatment.

Study Details

Study typeFda approval

PublishedDec 1989

View Original Abstract ↓

1 INDICATIONS AND USAGE ZOLADEX is a Gonadotropin Releasing Hormone (GnRH) agonist indicated for: Use in combination with flutamide for the management of locally confined carcinoma of the prostate ( 1.1 ) Palliative treatment of advanced carcinoma of the prostate ( 1.2 ) The management of endometriosis ( 1.3 ) Use as an endometrial-thinning agent prior to endometrial ablation for dysfunctional uterine bleeding ( 1.4 ) Use in the palliative treatment of advanced breast cancer in pre- and perimenopausal women ( 1.5 ) 1.1 Stage B2-C Prostatic Carcinoma ZOLADEX is indicated for use in combination with flutamide for the management of locally confined Stage T2b-T4 (Stage B2-C) carcinoma of the prostate. Treatment with ZOLADEX and flutamide should start 8 weeks prior to initiating radiation therapy and continue during radiation therapy [see Dosage and Administration ( 2.1 ) and Clinical Studies ( 14.1 )]. 1.2 Prostatic Carcinoma ZOLADEX is indicated in the palliative treatment of advanced carcinoma of the prostate [see Dosage and Administration ( 2.2 ) and Clinical Studies ( 14.2 )]. 1.3 Endometriosis ZOLADEX is indicated for the management of endometriosis, including pain relief and reduction of endometriotic lesions for the duration of therapy. Experience with ZOLADEX for the management of endometriosis has been limited to women 18 years of age and older treated for 6 months [see Dosage and Administration ( 2.3 ) and Clinical Studies ( 14.3 )]. 1.4 Endometrial Thinning ZOLADEX is indicated for use as an endometrial-thinning agent prior to endometrial ablation for dysfunctional uterine bleeding [see Dosage and Administration ( 2.4 ) and Clinical Studies ( 14.4 )]. 1.5 Advanced Breast Cancer ZOLADEX is indicated for use in the palliative treatment of advanced breast cancer in pre- and perimenopausal women. The estrogen and progesterone receptor values may help to predict whether ZOLADEX therapy is likely to be beneficial [see Dosage and Administration ( 2.5 ), Clinical Pharmacology ( 12.1 ), and Clinical Studies ( 14.5 )]. The automatic safety feature of the syringe aids in the prevention of needlestick injury.