The reason they make you take propecia is so the hairs that were not transplanted do not fall out, typically those hairs taken from the donor follicle are not sensitive to DHT, thats they the hairs on the back of your head never fall out
I was on propecia for a good 3 or 4 years and it fucked me up but my hair was thick as fuck, when I got on it my hair was thinning and my hairline was receding I was around 27 when I got on it, because I was tired of seeing the shedding in the shower
What I did was take it every other day I bought Generic Proscar and got it at walgreens for like 9 bucks for month supply but it lasted me 3 months. I cut it in 4 or five tiny pieces and took it every other day.
I got on it but decided first I will shave my hair to the skin for the first month and then let the hair grow back to be surprised, and after 6 months my hair was thicker and by year 2 my hair was good
I got off the stuff because of the bad sides, it killed my libido, memory issues nipple soreness, aching balls, watery semen, depression and suicidal thoughts, and insomnia