Everyone is different in this respect, but you should begin to notice changes after listening daily for one to three weeks. The more you listen, the easier it will be to relax, and the more change you'll notice. Once you've achieved the desired result, listening to this recording from time to time will help you maintain your success.
Highly hypnotizable people may experience benefit in as little as one session. Some people are either unable to be hypnotized or have low hypnotizability, in which case self-hypnosis may not be effective, or it may require listening over a longer period of time to notice changes.