When you switch to finasteride and stop OM, all the gains you made with OM will be lost. finasteride does not replace min, they work hand in hand via different pathways. Min gains do not stay upon stopping the treatment if that were the case everyone here would be on min. It is a life long commitment just like finasteride. Also start with topical and see if that works, if that's too bothersome then don't bother trying to save your hair. OM is a strong drug, don't underestimate it, it is nearly the last resort drug for people with uncontrollably high blood pressure. In perfectly healthy men it could still very likely cause heart issues with long-term use (3 years is long). Exhaust your options with topical min, add tretinoin, add microneedling.