how long can doxycycline stay in your system
With no more doxycycline, your body will eliminate almost all of the drug in 5.5 x half life = 5.5 days. Note. Some rounding liberties have been taken here but because maximum half life is 22 hours and not 24 hours, for all practical purposes 5 days after your last 100mg dose you have no doxycycline in your system.