text: how long does it take a prescription like wellbutrin to start working? i've recently started taking wellbutrin and have been on it now for about 3 weeks. i actually think its making my depression worse. i am quieater, dont talk to people very much, lose my patience and cry more now than before. this was supposed to help me! my friends have noticed that i'm not acting like myself lately. i dont think its the dosage. does it matter what time you take it at? most antidepressants take 6-8 weeks to completely kick in.  depending on what kind of wellbutrin you're taking, sr or xl, the time of day does matter.  if you only have to take wellbutrin sr once a day, take it in the morning.  if you are taking wellbutrin xl, i would take it in the morning, if it doesn't make you too drowsy.  but i don't think it makes that big of a difference.   if it doesn't work in the next few weeks, go back to your doctor.  some antidepressants don't work for some people.  there are so many different ones and there may be a medication that works better.