How long does it take for Paxil (paroxetine) cr to be out of your system so that it will not show up on a blood test?

2 weeks or so. The elimination half life of Paxil (paroxetine) cr is between 15 to 20 hours. So that each 15 to 20 hours 50 % is gone. Depend how sensitive the test is, it will never become zero. Like this, 1/2 at 15 hours, 1/4 at 30 hours, 1/8 at 45 hours, 1/16 at 60 hours, 1/32 at 75 hours, 1/64 at 90 hours, etc. It will never reach zero. Just very small amount. So probably 2 weeks would be a safe bet.
Probably 14 days. In swithing patients from this drug to a monoamine oxidase inhibitor antidepressant, it is recommended that at least 14 days should be allowed after stopping Paxil (paroxetine) before starting an maoi antidepressant. So it likely takes 14 days to clear Paxil (paroxetine) as it cannot be present when the other drug is given for fear of side effects like serotonin syndrome, which can also heppen if Paxil (paroxetine) is stopped too fast.