ive just turned 20 like a week ago & 3months ago I noticed thinning hair on my temples. Im now taking propecia 1 pill a day & I wash my hair once every 3 days with Nizoral shampoo (taking care to let it settle on my scalpe where the hair is thinning). things seem to be going ok for me- hairs arent falling out like they were before.
I would say the big 3 is your best bet or the shaving your head. The big three was working for me untill the sides arrived from finasteride then I developed a bad reaction to minoxidil (after a year).
If you can stop the hairloss with finasteride without sides, ideal, then you could get some FUE work done to the temple area and you could have a full head of hair for many years.