I used Compound W on a plantar wart for a month and it has fallen off. Do I need to keep using it?

Stop using Compound W once the wart falls off.

You won't need to use it again as long as the wart stays away. If it begins to grow back again or new warts appear you will need to start treatment again and can assume you still have the virus.

Plantar warts are caused by an infection with the human papillomavirus (HPV) in the outer layer of skin on the soles of your feet. The viruses thrive in warm, moist environments and enters the body through tiny cuts, breaks or other weak spots on the bottom of your feet. Typically the virus is caught off shower floors, locker rooms and public swimming areas.

Eventually the immune system will destroy the virus and the warts will disappear on their own but this can take some time.

For more information see:
https://www.drugs.com/mcd/plantar-warts