Goserelin Acetate

Goserelin acetate is a synthetic analogue of gonadotropin-releasing hormone (GnRH), belonging to the class of gonadotropin-releasing hormone receptor agonists. It is supplied as a biodegradable subcutaneous implant that provides continuous release of goserelin over several weeks. Unlike the natural pulsatile release of GnRH, continuous exposure to goserelin initially stimulates pituitary gonadotropin release and then produces sustained suppression of luteinizing hormone and follicle-stimulating hormone secretion through downregulation of GnRH receptors. This lowers testosterone production in men and reduces ovarian estrogen production in premenopausal women. Goserelin is clinically important because hormonal stimulation contributes to the growth of several hormone-dependent cancers and can also contribute to conditions such as endometriosis. In the United States, goserelin implants are approved for advanced prostate cancer, selected locally confined prostate cancer in combination with flutamide and radiotherapy, advanced breast cancer in pre- and perimenopausal women, endometriosis, and endometrial thinning before ablation for dysfunctional uterine bleeding. It is administered subcutaneously, most commonly as a 3.6 mg implant every 28 days, with a 10.8 mg formulation available for selected prostate cancer treatment. Because treatment produces profound sex-hormone suppression, monitoring for hormonal, metabolic, skeletal, cardiovascular, and disease-specific effects is important.

Goserelin was developed as a potent synthetic GnRH analogue designed to produce sustained suppression of gonadal hormone production when administered continuously. Its mechanism was established through the characteristic initial stimulation followed by pituitary GnRH-receptor downregulation and suppression of gonadotropin secretion. The U.S. Food and Drug Administration initially approved goserelin implant in 1989. Subsequent U.S. approvals expanded its use to additional prostate cancer, endometriosis, endometrial-thinning, and advanced breast cancer indications. The current U.S. prescribing information was revised in March 2026 and includes major safety updates concerning severe cutaneous adverse reactions. Goserelin products have also been authorized in European countries through national procedures; an EMA review in 2011 assessed several generic 3.6 mg goserelin products in relation to therapeutic equivalence with the reference medicine. In India, the Central Drugs Standard Control Organisation has documented regulatory consideration and approval-related updates for goserelin acetate depot injection, including a 10.8 mg formulation. Key clinical development programs established goserelin activity in prostate cancer, endometriosis, and hormone-sensitive breast cancer. Randomized studies also demonstrated the value of goserelin with radiotherapy in locally advanced prostate cancer and evaluated its role in ovarian-function preservation during chemotherapy.

Goserelin acetate is used in hormone-dependent clinical conditions according to the strength, formulation, and applicable local regulatory approval. U.S. labeling includes palliative treatment of advanced prostate cancer and use with flutamide and radiotherapy for locally confined Stage T2b-T4 prostate carcinoma. It is also indicated for management of endometriosis, including reduction of endometriotic lesions and associated pain, for use as an endometrial-thinning agent before endometrial ablation for dysfunctional uterine bleeding, and for palliative treatment of advanced breast cancer in pre- and perimenopausal women. In cancer treatment, goserelin may be administered with other therapies when clinically indicated rather than necessarily as monotherapy. Goserelin has also been investigated in other settings, including ovarian protection during chemotherapy, but such use should not be assumed to be an approved indication in every country. Treatment selection should be based on the disease, hormone-receptor status where relevant, menopausal status, previous treatment, and applicable prescribing guidance.

Goserelin is administered as a subcutaneous biodegradable implant into the anterior abdominal wall below the navel line using an aseptic technique. The commonly used 3.6 mg implant is administered every 28 days. For advanced prostate cancer and advanced breast cancer, treatment is generally continued long term unless clinically inappropriate. For endometriosis, the U.S. prescribing information recommends treatment for six months in women aged 18 years and older, with longer treatment or routine retreatment requiring careful consideration because of bone-mineral-density effects and limited safety data. Before endometrial ablation for dysfunctional uterine bleeding, one or two 3.6 mg depots may be administered four weeks apart according to the surgical schedule. A 10.8 mg implant is administered every 12 weeks for selected prostate cancer indications. No dosage adjustment is required for renal or hepatic impairment according to current U.S. labeling. Patients should be monitored according to the indication for hormone suppression, disease response, metabolic effects, bone health, and treatment-related adverse reactions.

Common side effects of goserelin are related mainly to suppression of sex hormones and vary according to sex and treatment indication. In men, frequently reported effects include hot flashes, sexual dysfunction, reduced erections, and lower urinary tract symptoms. Women may experience hot flushes, sweating, headache, emotional changes, reduced libido, vaginal symptoms, breast atrophy, acne, and peripheral edema. Menstrual changes or cessation of menstruation can occur in premenopausal women. Reduced estrogen or testosterone levels may contribute to fatigue, mood changes, sexual difficulties, and loss of bone mineral density during longer treatment. Temporary worsening of symptoms may also occur when treatment begins because of the initial hormone surge. Most adverse effects are manageable with appropriate clinical supervision, but persistent or severe symptoms should be evaluated by the treating healthcare professional.

Important serious risks include tumor flare during the initial treatment period, hypersensitivity and anaphylactic reactions, metabolic changes, cardiovascular events, hypercalcemia in patients with bone metastases, severe cutaneous adverse reactions, injection-site or vascular injury, and effects on cardiac repolarization. In men receiving GnRH agonists, hyperglycemia and an increased risk of diabetes have been reported, while cardiovascular risks including myocardial infarction, sudden cardiac death, and stroke require attention. In prostate cancer, initial testosterone elevation may temporarily worsen bone pain or, in susceptible patients, contribute to ureteral obstruction or spinal cord compression. Women receiving goserelin may experience depression or worsening of depressive symptoms. Severe cutaneous reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, and acute generalized exanthematous pustulosis have been reported and require treatment interruption and, when confirmed, permanent discontinuation. Pregnancy is generally contraindicated except when goserelin is specifically being used for palliative treatment of advanced breast cancer.

Before treatment, clinicians should review the indication, pregnancy status where relevant, cardiovascular and metabolic risk factors, bone-health considerations, history of hypersensitivity, and medications that may influence cardiac rhythm or hormonal treatment. Women of childbearing potential should have pregnancy excluded before treatment for benign gynecological indications and should use effective nonhormonal contraception during treatment and for the recommended period after discontinuation. Patients with prostate cancer at risk of spinal cord compression or ureteral obstruction require particular attention during the initial treatment period. Blood glucose or HbA1c should be monitored periodically in men receiving GnRH agonist therapy, especially when diabetes or metabolic risk factors are present. Bone mineral density may require assessment during prolonged sex-hormone suppression, particularly when additional risk factors for osteoporosis exist. Current U.S. labeling does not identify established clinically significant drug interactions with goserelin, although concomitant medicines should still be reviewed for additive QT effects, cardiovascular risks, and treatment-specific considerations.

Prescribers should confirm the indication, formulation strength, treatment interval, and hormone-dependent disease characteristics before administration. Pregnancy should be excluded when required, and baseline assessment should consider glucose control, cardiovascular risk, bone health, symptoms of urinary obstruction, and relevant cancer burden. For prostate cancer, clinicians should anticipate the initial testosterone flare and consider appropriate concomitant therapy when clinically indicated to reduce flare-related complications. Pharmacists should verify the depot strength and scheduled administration interval because 3.6 mg and 10.8 mg implants have different dosing frequencies. Administration requires careful attention to the anterior abdominal wall because the inferior epigastric vessels are nearby, particularly in patients with low body mass or those receiving full-dose anticoagulation. Patients should be counselled about hot flashes, menstrual changes, sexual effects, mood changes, and the importance of reporting severe rash, chest pain, neurological symptoms, severe bone pain, urinary obstruction, or allergic symptoms promptly.