"my doctor prescribed 10mg lexapro for severe anxiety about 5months ago.  the first 4 weeks were really rough as the side effects almost caused me to discontinue the medicine. by the 4th week, i had insomnia.  i couldn&#039;t sleep for several days.  i felt like i was on speed.  so, i cut the pill in half and the next day i felt a difference.  i&#039;ve been on 5mg for the last 4 months. and, i must say that it has changed my life for the better.  i no longer have those negative thoughts or bouts of anxiety. its amazing.  the only side effects that continue are: clenching of the jaw and weight gain due to an increase in appetite. if you take lexapro, give it 4 to 5 weeks to work before giving up. best of luck."