There is a wide variety of treatments for an enlarged prostate that can take anywhere from a few days to several months to work. Some medications, like alpha blockers that loosen bladder and prostate muscles, can begin working noticeably within a couple of days. On the other hand, drugs like 5-alpha-reductase inhibitors that reduce the size of the prostate can take several months before an effect is apparent. A surgical procedure like transurethral resection of the prostate (TURP), which uses a tube inserted through the urethra to remove a portion of the prostate, can improve symptoms within a few days. However, similar procedures using needles or microwaves to remove part of the gland can take weeks or months to take effect.