Some guys here have reported decrease/thinning of body hair after being on finasteride a while, but I've also heard that it was hogwash. It would be nice, though, I could stand to be a bit less hairy.
I have had a reduction in body hair. I'd estimate the reduction was about 20% where the hair simply grows slower and less dense. Before finasteride I'd go through about one razor a week for shaving, after finasteride I go about 2.5 weeks.
i had a reduction, not that i had the genes to be really hairy to begin with, but my stomach is virtually hairless as it did have some more darker hair before finasteride, same goes with hair in other general places