In the 70 years following the first description of the benefits of surgical castration, despite advances in medical therapy e.g. cabazitaxel, enzalutamide, abiraterone, androgen deprivation therapy (ADT) remains the cornerstone of treatment for advanced prostate cancer. However, with increasing numbers of men undergoing PSA testing, the disease is being diagnosed earlier and the costs of ADT, with uncertain survival benefits and associated risks, have risen dramatically. Clinical studies of potent novel agents have shown survival benefits in advanced disease, but timing, risks and cost-effectiveness of treatment remain controversial. As new agents enter clinical practice, a comprehensive research strategy is essential to optimise benefits whilst minimising harm.