You will lose the hair that would not have grown without Minoxidil. For example, if Minoxidil made you grow hair on your forehead, Finasteride would not keep this hair and you would lose it upon cessation (as an example). It does not mean you will lose everything you gained however because it could have also just stimulated and supported what was already going to grow. In this case, you probably wouldn't lose this. I used Minoxidil for six months 10yrs ago and stopped and did not lose it all.