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Low-dose Zoladex will no longer be available in Australia from November 2026. This change has significant implications for patients relying on this medication for hormone-sensitive conditions.
What is Zoladex?
Zoladex, known generically as goserelin, is a synthetic hormone that suppresses the production of testosterone in men and oestrogen in women. It has been a cornerstone treatment for prostate cancer, endometriosis, and certain breast cancers in Australia for decades.
Prostate cancer, which accounts for 30% of all cancer diagnoses in Australian men, relies on testosterone for growth. By reducing testosterone levels, Zoladex helps slow or stop tumour development. This approach is called androgen deprivation therapy.
In women, Zoladex is used for ER+ breast cancers that require oestrogen to grow, particularly in pre-menopausal women. It also helps manage endometriosis symptoms by lowering oestrogen levels, which reduces pain and inflammation.
Two formulations are registered in Australia: a low-dose 3.6 mg implant administered monthly, and a high-dose 10.8 mg implant given every three months. Both contain the same active ingredient and are injected under the skin.
Why is Low-Dose Zoladex Being Removed?
AstraZeneca, the manufacturer, has decided to discontinue the low-dose version for commercial reasons, unrelated to safety or efficacy. While the exact reasons are undisclosed, one factor may be lower demand in Australia compared to global markets. In 2025, nearly 100,000 prescriptions were filled in Australia, but the country represents only 2.1% of global medicine demand. Producing two products instead of one may be less profitable for AstraZeneca.
Other possible reasons include cost-cutting or reallocating manufacturing capacity to produce new or existing medicines.
What Are Your Options After November?
AstraZeneca will keep low-dose Zoladex available until November 1, 2026, to allow patients and clinicians time to transition. After that date, the high-dose form will remain on the market. The company is applying for PBS listing for the high-dose version to make it more affordable.
For some patients, switching to the high-dose formulation may be appropriate. However, if that is not suitable, doctors can recommend alternative treatments. For prostate cancer, over 20 different drug combinations exist, with only one including Zoladex. For breast cancer, more than 90 chemotherapy plans are available, though only three require Zoladex. Women with endometriosis may use other hormone therapies like contraceptives or progestogen tablets.
Key Takeaways
- Low-dose Zoladex will be unavailable from November 2026.
- High-dose Zoladex remains available and may be listed on PBS.
- Alternative treatments exist for all conditions.
- Speak to your doctor or pharmacist about your specific situation.
If you currently take low-dose Zoladex, do not panic. Consult your healthcare provider to discuss the best path forward. The transition period provides ample time to adjust your treatment plan.
