Dear Dr. Rassman,
How long does it take for minoxidil dependence to occur ( once use has been started)
I do not know the definite answer to this, as there are no studies published about it (to my knowledge). First, the hair must be responsive to minoxidil for it to become dependent upon it and that means that the hair is thin and not normal. This generally takes many months, to a point where the drug is making a difference.
If you put a non-balding person on minoxidil, I believe that the hair would not develop a dependence upon it.