Do foot levelers work?

Yes: If support is needed for the foot then a proper fitting orthotic will help.

Not as much as..: They'd like you to think. I've had patients who have worn them who find the various pads lumpy and uncomfortable. The underlying principles of stabilizing/supporting the feet aren't bad, but the execution of these principles leaves much to be desired. Depending on the nature of your problem a good set of custom orthotics, made well, and by a podiatrist trained in biomechanics is much better.

Yes: If you are referring to a shoe heel lift or orthotic inserts, they work very well when used in the correct way and for a specific diagnosis! Best wishes!