This is a great question as you are asking how long it will take to fully regrow all your hair. In our practice we offer multiple hair restoration options- from prescription topical medications, vitamins, red light treatment, to PRP to hair transplantation. All these treatments, before hair transplantation- all offer some degree of hair loss improvement, from reducing the progression of hair loss, to thickening hair, to growing hair. One thing all these treatments do not promise is to 'regrow all your hair'. This is a very important part of the hair restoration consultation process- to manage expectations. So the same goes for topical minoxidil, it can improve or slow down the hair loss, but it rarely regrows all the lost hair. Now that I got this out the way with, I agree with all the other answers below, it takes few weeks to see initial results and then you should continue with the treatment to maintain its effectiveness.