Rob Brydon has admitted having a hair transplant, they joked about it on The Trip.
Alan Carr, Declan Donnelly, Martin Keown and Derren Brown also seem to have miraculously reversed male pattern balding.
Ickle Dec has definitely had something done. A year or so ago he was going very thin, now he has a luxuriant barnet. My thinking here is a 'weave/strand by strand' whatever they call it?