hey anon it will take about two weeks for them to completely leave your system but if you have been taking them for longer than a week you should probably talk to your doctor, as coming off of them can seriously impact your health as they can present things like withdrawal symptoms, also remember that they can take up to a month to actually work properly and in the meantime they can actually make things worse, i was on citalopram and felt like they worked for a while before i was moved onto sertraline and im not sure how well thats going lol, but anyway about two weeks and if you have only taken them for a short amount of time then try to be patient before you give up on them, whilst medication isn't for everyone it can help short time whilst you are getting other support for things like counselling, if you ever feel suicidal and need someone to talk to call the Samaritans, they're 24hrs and unlike childline wont turn you away no matter your age