its very hard to regrow there. im in the same situation and using minoxidil (rogaine). yesterday i added azelaic acid to my regimen, now im expecting good results with these. hair transplant is the most effective thing, but its kind of expensive. minoxidil and azelaic acid is an alternative, give it a try... there are products which contains these two together, e.g lipogaine. but you can buy azelaic acid and genereal minoxdil separately, this way is cheaper.