Taking 1mg finasteride, told by doctor to add topical finasteride

That makes no sense to me, as adding topical finasteride while you are taking oral finasteride at the 1mg dose, will add blood levels of finasteride.  With topical finasteride, the drug will come across the scalp and go into your body. There is therefore no reason to add topical finasteride once you are on the proper dose of oral finasteride.