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zoladex

Zoladex (Goserelin Acetate) is a medication used to treat Breast Neoplasms, Endometriosis, Prostatic Neoplasms.

Goserelin Acetate · by Tersera

Not yet rated· sourced from the FDA label
Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
Verified againstopenFDANIH DailyMedRxClass

Key facts

Active ingredient
Goserelin Acetate
Form
Implant
Strength
Goserelin Acetate EQ 3.6MG Base
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Tersera
FDA application
NDA019726

What is Zoladex?

From the FDA label:ZOLADEX (goserelin implant) is a GnRH agonist. Goserelin acetate is chemically described as an acetate salt of [D-Ser(Bu t ) 6 ,Azgly 10 ]. Its chemical structure is pyro-Glu-His-Trp-Ser-Tyr-D-Ser(Bu t )-Leu-Arg-Pro-Azgly-NH 2 acetate [C 59 H 84 N 18 O 14· (C 2 H 4 O 2 ) x where x = 1 to 2.4]. Goserelin acetate is an off-white powder with a molecular weight of 1269 Daltons (free base). It is freely soluble in glacial acetic acid. It is soluble in water, 0.1M hydrochloric acid, 0.1M sodium hydroxide, dimethylformamide and dimethyl sulfoxide. Goserelin acetate is practically insoluble in acetone, chloroform and ether. ZOLADEX is supplied as a sterile, biodegradable product containing 3.8 mg goserelin acetate, equivalent to 3.6 mg of goserelin. ZOLADEX is designed for subcutaneous injection with continuous release over a 28-day period. Goserelin acetate, containing up to 12% goserelin-related substances, is dispersed in a matrix of D,L-lactic and glycolic acids copolymer (to a total implant weight of 18.0 mg, containing less than 2.5% total acetic acid) and presented as a sterile, white to cream colored 1-mm diameter cylinder, preloaded in a special single use syringe with a 16-gauge x 36 +/- 0.5 mm siliconized needle with protective needle sleeve (SafeSystem ® Syringe) in a sealed, light- and moisture-proof, aluminum foil laminate pouch containing a desiccant capsule. Studies of…

How to use

ZOLADEX, at a dose of 3.6 mg, should be administered subcutaneously every 28 days into the anterior abdominal wall below the navel line using an aseptic technique under the supervision of a physician [see Dosage and Administration ( 2.7 )]. While a delay of a few days is permissible, every effort should be made to adhere to the 28-day schedule. ZOLADEX 3.6 mg should be administered subcutaneously every 28 days ( 2.1 , 2.7 ) For the management of endometriosis, the recommended duration of administration is 6 months for women 18 years of age and older ( 2.3 ) 2.1 Stage B2-C Prostatic Carcinoma When ZOLADEX is given in combination with radiotherapy and flutamide for patients with Stage T2b-T4 (Stage B2-C) prostatic carcinoma, treatment should be started 8 weeks prior to initiating radiotherapy and should continue during radiation therapy. A treatment regimen using a ZOLADEX 3.6 mg depot 8 weeks before radiotherapy, followed in 28 days by the ZOLADEX 10.8 mg depot, can be administered. Alternatively, four injections of 3.6 mg depot can be administered at 28-day intervals, two depots preceding and two during radiotherapy. 2.2 Prostatic Carcinoma For the management of advanced prostate cancer, ZOLADEX is intended for long-term administration unless clinically inappropriate. 2.3 Endometriosis For the management of endometriosis, the recommended duration of administration is 6 months.…

Side effects

The most common, clinically significant adverse reactions occurring in >10% of men: hot flashes, sexual dysfunction, decreased erections and lower urinary tract symptoms ( 6 ) The adverse event profile was similar for women treated for breast cancer, dysfunctional uterine bleeding or endometriosis and included (>20%): hot flushes, headache, sweating, acne, emotional lability, depression, decreased libido, vaginitis, breast atrophy, seborrhea, and peripheral edema ( 6 ) Tumor flare can occur on the initiation of ZOLADEX for both men and women being treated for cancer ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact TerSera Therapeutics at 1-844-334-4035 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Stage B2-C Prostatic Carcinoma Treatment with ZOLADEX and flutamide did not add substantially to the toxicity of radiation treatment alone. The following adverse experiences were reported during a multicenter clinical trial comparing ZOLADEX + flutamide + radiation versus radiation alone. The most frequently reported (greater than 5%) adverse experiences are listed below: Table 1 ADVERSE EVENTS DURING ACUTE RADIATION THERAPY (within first 90 days of radiation therapy) (n=231) flutamide + ZOLADEX + Radiation % All (n=235) Radiation Only % All Rectum/Large Bowel 80 76 Bladder 58 60 Skin 37 37 Table 2 ADVERSE EVENTS DURING LATE RADIATION PHASE (after 90 days of radiation…

Warnings

Important safety information

Women of Childbearing Potential and Pregnancy: Pregnancy must be excluded for use in benign gynecological conditions. Women should avoid pregnancy ( 5.1 ) Tumor Flare Phenomenon: Transient worsening of tumor symptoms may occur during the first few weeks of treatment with ZOLADEX, which may include ureteral obstruction and spinal cord compression. Monitor patients at risk for complications of tumor flare ( 5.2 , 6.2 ) Hyperglycemia and Diabetes: Hyperglycemia and an increased risk of developing diabetes have been reported in men receiving GnRH analogs. Monitor blood glucose level and manage according to current clinical practice ( 5.3 ) Cardiovascular Diseases: Increased risk of myocardial infarction, sudden cardiac death and stroke has been reported in association with use of GnRH analogs in men. Monitor for cardiovascular disease and manage according to current clinical practice ( 5.4 ) Hypercalcemia: Hypercalcemia has been reported in patients with bone metastases treated with ZOLADEX. Monitor and manage appropriately ( 5.5 ) Hypersensitivity: Systemic hypersensitivity has been reported in patients receiving goserelin/ZOLADEX implants ( 4.1 , 5.6 ) Severe Cutaneous Adverse Reactions: ZOLADEX can cause severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome/toxic epidermal necrolysis. Interrupt ZOLADEX if signs or symptoms of SCARs develop. Permanently discontinue ZOLADEX if SCARs are confirmed. ( 5.7 ) Cervical Resistance: Increase in cervical resistance may occur. Caution is recommended when dilating the cervix for endometrial ablation ( 5.8 ) Effect on QT/QTc Interval: Androgen deprivation therapy may prolong the QT interval. Consider risks and benefits ( 5.9 ) Injection Site Injury: Injection site injury and vascular injury have been reported during administration of ZOLADEX ( 5.10 ) Depression: Depression may occur or worsen in women receiving GnRH agonists. Monitor and manage appropriately ( 5.11 ) 5.1 Women of Childbearing Potential and Pregnancy Before starting treatment with ZOLADEX, pregnancy must be excluded for women using ZOLADEX for benign gynecological conditions. Women of childbearing potential should be advised to avoid becoming pregnant. Effective nonhormonal contraception must be used by all premenopausal women during ZOLADEX therapy and for 12 weeks following discontinuation of therapy. When used every 28 days, ZOLADEX usually inhibits ovulation and stops menstruation; however, pregnancy prevention is not ensured. Effects on reproductive function are expected to occur with chronic administration as a result of the anti-gonadotrophic properties of the drug. Based on mechanism of action in humans and findings of increased pregnancy loss in animal studies, ZOLADEX can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy for the palliative treatment of breast cancer, then the patient should be apprised of the potential hazard to the fetus [see Use in Specific Populations ( 8.1 )]. 5.2 Tumor Flare Phenomenon Initially, ZOLADEX, like other GnRH agonists, causes transient increases in serum levels of testosterone in men with prostate cancer, and estrogen in women with breast cancer. Transient worsening of symptoms, or the occurrence of additional signs and symptoms of prostate or breast cancer, may occasionally develop during the first few weeks of ZOLADEX treatment. A small number of patients may experience a temporary increase in bone pain, which can be managed symptomatically. As with other GnRH agonists, isolated cases of ureteral obstruction and spinal cord compression have been observed in patients with prostate cancer. If spinal cord compression or renal impairment secondary to ureteral obstruction develops, standard treatment of these complications should be instituted. For extreme cases in prostate cancer patients, an immediate orchiectomy should be considered. 5.3 Hyperglycemia and Diabetes Hyperglycemia and an increased risk of developing diabetes have been reported in men receiving GnRH agonists. Hyperglycemia may represent development of diabetes mellitus or worsening of glycemic control in patients with diabetes. Monitor blood glucose and/or glycosylated hemoglobin (HbA1c) periodically in patients receiving a GnRH agonist and manage with current practice for treatment of hyperglycemia or diabetes [see Patient Counseling Information ( 17.2 )]. 5.4 Cardiovascular Diseases Increased risk of developing myocardial infarction, sudden cardiac death and stroke has been reported in association with use of GnRH agonists in men. The risk appears low based on the reported odds ratios, and should be evaluated carefully along with cardiovascular risk factors when determining a treatment for patients with prostate cancer. Patients receiving a GnRH agonist should be monitored for symptoms and signs suggestive of development of cardiovascular disease and be managed according to current clinical practice [see Patient Counseling Information ( 17.2 )]. 5.5 Hypercalcemia As with other GnRH agonists or hormonal therapies (antiestrogens, estrogens, etc.), hypercalcemia has been reported in some prostate and breast cancer patients with bone metastases after starting treatment with ZOLADEX. If hypercalcemia does occur, appropriate treatment measures should be initiated. 5.6 Hypersensitivity Hypersensitivity, antibody formation and acute anaphylactic reactions have been reported with GnRH agonist analogues [see Contraindications ( 4.1 )] . Of 115 women worldwide treated with ZOLADEX and tested for development of binding to goserelin following treatment with ZOLADEX, one patient showed low-titer binding to goserelin. On further testing of this patient's plasma obtained following treatment, her goserelin binding component was found not to be precipitated with rabbit antihuman immunoglobulin polyvalent sera. These findings suggest the possibility of antibody formation. 5.7 Severe Cutaneous Adverse Reactions ZOLADEX can cause severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP). SCARs, including SJS/TEN, DRESS, and AGEP, occurred in patients receiving ZOLADEX or other GnRH agonists; including cases with visceral involvement and/or requiring skin grafts [see Adverse Reactions ( 6.10 ) and Patient Counseling Information ( 17.1 )] . Monitor patients for the development of SCARs. If a SCAR is suspected, interrupt ZOLADEX until the etiology of the reaction has been determined. Consultation with a dermatologist is recommended. If a SCAR is confirmed, or for other grade 4 skin reactions, permanently discontinue ZOLADEX. 5.8 Cervical Resistance The pharmacologic action of ZOLADEX on the uterus and cervix may cause an increase in cervical resistance. Therefore, care should be taken when dilating the cervix for endometrial ablation. 5.9 Effect on QT/QTc Interval Androgen deprivation therapy may prolong the QT/QTc interval. Providers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities, and in patients taking drugs known to prolong the QT interval. Electrolyte abnormalities should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes. 5.10 Injection Site Injury Injection site injury and vascular injury including pain, hematoma, hemorrhage and hemorrhagic shock, requiring blood transfusions and surgical intervention, have been reported with ZOLADEX. Extra care should be taken when administering ZOLADEX to patients with a low BMI and/or to patients receiving full dose anticoagulation [see Dosage and Administration ( 2.7 ) and Patient Counseling Information ( 17.2 and 17.3 )]. 5.11 Clinical Depression Depression may occur or worsen in women…

Who should not take Zoladex

Hypersensitivity ( 4.1 ) Pregnancy unless used for treatment of advanced breast cancer ( 4.2 ) 4.1 Hypersensitivity Anaphylactic reactions to ZOLADEX have been reported in the medical literature. ZOLADEX is contraindicated in those patients who have a known hypersensitivity to GnRH, GnRH agonist analogues or any of the components in ZOLADEX [see Warnings and Precautions ( 5.6 )]. 4.2 Pregnancy ZOLADEX is contraindicated during pregnancy unless ZOLADEX is being used for palliative treatment of advanced breast cancer. ZOLADEX can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy, the patient should be apprised of the potential hazard to the fetus. There is an increased risk for pregnancy loss due to expected hormone changes that occur with ZOLADEX treatment [see Use in Specific Populations ( 8.1 )].

Overdose — what happens if you take too much

The pharmacologic properties of ZOLADEX and its mode of administration make accidental or intentional overdosage unlikely. There is no experience of overdosage from clinical trials. Animal studies indicate that no increased pharmacologic effect occurred at higher doses or more frequent administration. Subcutaneous doses of the drug as high as 1 mg/kg/day in rats and dogs did not produce any nonendocrine related sequelae; this dose is up to 250 times the estimated human daily dose based on the body surface area. If overdosage occurs, it should be managed symptomatically.

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Interactions

No formal drug-drug interaction studies have been performed. No confirmed interactions have been reported between ZOLADEX and other drugs. None 7.1 Drug/Laboratory Test Interactions Administration of ZOLADEX in therapeutic doses results in suppression of the pituitary-gonadal system. Because of this suppression, diagnostic tests of pituitary-gonadotropic and gonadal functions conducted during treatment and until the resumption of menses may show results which are misleading. Normal function is usually restored within 12 weeks after treatment is discontinued.

May treat (source: NIH RxClass)

Dosage forms

Implant

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

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Frequently asked questions

What does Zoladex treat?
Zoladex (Goserelin Acetate) may be used to treat breast neoplasms, endometriosis, prostatic neoplasms, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
Is there a coupon or discount for Zoladex?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Zoladex. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Zoladex?
Zoladex is marketed by Tersera. You can see Tersera's full profile, rating, and other products on pharmaranks.
Is Zoladex a brand-name or generic drug?
Zoladex is a brand-name product with the active ingredient Goserelin Acetate.
Is Zoladex available over the counter?
No. Zoladex is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Zoladex come in?
Zoladex is currently marketed as implant, per the FDA's National Drug Code Directory.
Is Zoladex FDA-registered?
Zoladex is on record with the U.S. FDA under application number NDA019726. You can verify this on its official FDA label.
Is Zoladex safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Zoladex. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Zoladex?
Zoladex's side effects are taken directly from its FDA label. From the label: The most common, clinically significant adverse reactions occurring in >10% of men: hot flashes, sexual dysfunction, decreased erections and lower urinary tract symptoms ( 6 ) The adverse event profile was similar for women treated for breast cancer,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

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