Goserelin: Uses, Mechanism, and Side Effects

Anyone prescribed goserelin for prostate cancer, breast cancer, or endometriosis is usually trying to understand how a hormone-blocking injection helps their specific condition. Goserelin has a long track record under the brand name Zoladex and a well-documented safety profile across hundreds of clinical trials.

Key takeaways

• Goserelin is a synthetic GnRH agonist sold as Zoladex, approved for several hormone-sensitive conditions.
• It works by suppressing pituitary gonadotropin secretion, which lowers sex hormone levels.
• Approved uses span prostate cancer, breast cancer, endometriosis, and endometrial thinning before ablation.
• More than 400 registered trials have studied goserelin, including work in metastatic prostate and breast cancer.
• FAERS reports linked to goserelin include death and disease progression terms, reflecting its use in advanced cancer populations.

What Goserelin Is

Goserelin is a synthetic decapeptide analogue of gonadotropin releasing hormone (GnRH). When delivered in its biodegradable formulation, it inhibits the release of gonadotropins from the pituitary gland. This action reduces the production of hormones such as testosterone and estrogen that can drive certain cancers and hormone-dependent conditions. Laboratory and animal studies have shown that goserelin can slow or reverse growth in hormonally sensitive tumor models.

What Goserelin Is Approved For

Under the brand name Zoladex, goserelin carries several FDA-approved indications. It is used together with flutamide for locally confined, Stage B2-C prostate carcinoma, and alone for palliative treatment of advanced prostate carcinoma. It is also approved for managing endometriosis, for thinning the uterine lining before endometrial ablation in dysfunctional uterine bleeding, and for palliative treatment of advanced breast cancer in pre- and perimenopausal women. The label does not carry a boxed warning.

What The Evidence Shows

Goserelin has been studied in 435 registered clinical trials. One completed Phase 2 trial examined discontinuing GnRH analogue therapy alongside abiraterone in metastatic prostate cancer. Another completed Phase 2 trial evaluated estradiol suppression for treating metastatic breast cancer in premenopausal women.

Reported Side Effects

FAERS reports associated with goserelin are dominated by terms reflecting advanced cancer status, including death, malignant neoplasm progression, and metastases to bone, alongside fatigue and asthenia. Neutropenia and nausea are also commonly reported, along with hot flush, a known effect of hormone suppression. These are counts of submitted reports, not confirmed rates of incidence or proof that goserelin caused the event.