How long is it supposed to it take diabetic foot neuropathy to develop?

Tough question: Because it does not develop in everyone, so I am not sure one really knows when it starts. It likely does precede when the person starts to become symptomatic. Some docs test patients via epidermal nerve fiber density testing. This can tell you if you have decreased small liner e fibers in the skin before being symptomatic.

Times vary.: Everyone is different. Neuropathy may develop quickly or it may take years to develop depending on a variety of factors.

Over time. : Neuropathy develops over time, but by the time you notice it, the damage has been done, and can often be irreversible at that point.