Goserelin Reference

Plain English

What it is

Goserelin is a prescription medicine sold under the brand name Zoladex. It is a lab-made copy of a natural brain hormone (called a GnRH agonist) that, after a short startup spike, switches off the signal the body uses to make its sex hormones. A doctor places it under the skin of the belly as a small implant.

What people use it for

Doctors use it to treat prostate cancer in men and advanced hormone-sensitive breast cancer in women. It is also used to treat endometriosis and to thin the lining of the womb before a procedure to remove that lining.

What the science shows

It has decades of evidence from its approved medical use. It works by quieting the pituitary gland so the body makes far less testosterone or estrogen, acting like a reversible, medicine-based way to lower those hormones. This drop in sex hormones happens reliably.

The catch

It is prescription-only and has to be placed by a clinician; off-label or self use is not safe. In men starting treatment for advanced prostate cancer, hormone levels briefly rise first and can temporarily make the tumor worse (called tumor flare). Over longer use it lowers bone density and brings on hot flashes and other low-hormone effects.

Reference summary

Goserelin is a decapeptide GnRH agonist with decades of approved-label oncology and gynecology evidence. After a brief LH/FSH surge it desensitizes the pituitary, producing reversible medical castration. The 3.6 mg one-month and 10.8 mg three-month implants are interchangeable depot formats. Bone mineral density loss, hot flashes, and metabolic shifts are well-characterized in long-duration label use; in men a tumor-flare phenomenon during the first 1-2 weeks is a known label concern that drives concurrent antiandrogen coverage at initiation in advanced prostate cancer.

Regulatory and posture

Categories

Reproductive, Hormonal

Aliases

Zoladex, GnRH agonist depot implant, ICI 118630

Evidence posture

human - Oncology / gynecology drug. Prescription-only and clinician-administered (depot implant inserted with a wide-bore needle); off-label or self-administered use is not safe. Tumor flare during the initial surge phase is a labeled risk in advanced prostate cancer.

Regulatory status

FDA-approved prescription medication (Zoladex). Indications include advanced prostate cancer (often combined with an antiandrogen for medical castration), early-stage hormone-receptor-positive breast cancer in pre- and perimenopausal women, palliative breast cancer, endometriosis, endometrial thinning before ablation, and uterine fibroid management before surgery. Prescription-only, clinician-administered as a biodegradable subcutaneous abdominal implant.

Content review status

label verified

Related tools

• Injection-site rotation overview - Public overview of the Pro site-rotation planner.