When will my overactive bladder medicine start to work?

2 weeks. Some times it takes 2 weeks for an overactive bladder medication to work or kick in.
2 weeks to 6 months. Depending on the med in can take longer than just a few weeks. Most meds show improvement at 2 weeks but go on to be doing a better job and helping more people by 3 months. Give it at least 3 months befor you call it a failure.