Individuals with prostate cancer are typically advised against testosterone therapy as part of gender affirming care due to potential risks associated with hormone-sensitive tumours. Testosterone, a primary component of masculinising hormone therapy, can stimulate the growth and proliferation of prostate cancer cells, potentially accelerating tumor growth or increasing the risk of cancer recurrence. Therefore, testosterone therapy is contraindicated in individuals with a history of prostate cancer or those currently undergoing treatment for the disease.