Transplanted hair receding years after HT.

[Jolly]

I too had a Transplant around 4 years Back , the 1st year was stellar result , good density and Nice coverage to my Norwood 4 , then since that there has been a steady fallout of the Transplanted hair , why I am so sure that it is Transplanted hair and Not Native hair ? ? well I had a slick bald area Hairline to mid scalp was Barren , so there were only transplanted hair in that area and those have been fallen out since the last 3 years to the point that today the density is lost by 50 % and my scalp is visible .
My doctor is not giving me any satisfactory explanation , I stumbled on this Post today and was shocked to see Many guys like me , struggling to find answer to this problem .
also on another famous site hair restore , many guys have reported but there also No One has any clue .
If any member can chime in please let us know the reason for such a phenomenon , as I am Lost for Answers . BTW I have never taken Propecia , yet the grafts ( FUE) grew in beautiful and dense for the first year Post Operation .
Any senior members like gillenator , spex , tillman pls do respond your take on this .