Intermittent hormone therapy is simply an interrupted or cycled version of hormone therapy, in which the therapy is stopped after the PSA drops to an undetectable level, and is re-started when it rises to a predetermined level. There is a great deal of discussion over what these levels should be, but most agree that the PSA should bottom out for at least two or three months, and the treatment should resume when the PSA reaches one-half the pre-treatment value. The two arguments for using intermittent therapy: It allows the patient to enjoy the benefits of testosterone for at least part of the time, and It may postpone the time when hormone therapy fails. Once hormone therapy fails you have limited treatment options.