PSA is a protein produced by the prostate gland. While often associated with prostate cancer screening, PSA levels are also affected by prostate size, inflammation, infection, recent ejaculation, and testosterone levels. TRT typically causes a modest PSA increase (0.3-0.5 ng/mL) as it stimulates prostate tissue.
A baseline PSA before starting TRT is essential, and any rapid rise (>1.4 ng/mL increase within 12 months or velocity >0.75 ng/mL per year) warrants urological evaluation regardless of absolute value.