Minoxidil causes dormant folicles (which have a hair in them) to turn on now rather than later which results in the hair shedding to allow a new hair to grow in its place.
There's no avoiding that.
My scalp has never had hair loss, I started minoxidil to grow a beard and have been applying on my beard/neck area.
The oral might increase my scalp hair but it would be hard to tell since it's already fairly thick.
This might not carry over 100% to scalp growth but switching from topical to...
I can second that oral minoxidil works (at least for me)
I've been applying topical on my face for beard growth for about a year and 3 months. At the year mark my results were pretty good, maybe a 40% increase in hair density but at the year mark I did 1 month of oral minoxidil 5mg 2x/day...