I've taken doxycycline, still having urethritis, how long does it take for urethra to heal?

Depends: Most of the time it's better within 2 weeks, so check with your doctor if not resolved or sooner if worse.

Normally 10 days: Usually 10 days should be enough if it is the right antibiotic, most urethritis is treated by doxycycline, it's interesting if you had cultures done prior to starting. Also depends what kind of urethritis you had? Was it am std? So if not better revisit your doctor and have cultures done.

A week to 10 days: If you have been on the doxy for ten days, it may be that the doxy is not effective in treating your condition. I recommend following up with the provider who diagnosed you and gave you the original, rx, and let them know you are still having symptoms.