 Humphrey Bogart (qv) started losing his hair in 1947, round about  the time he was making _Dark Passage (1947)_ (qv), partly because of  hormone shots he was taking to improve his chances of having a child  with wife Lauren Bacall (qv) (although his excessive drinking and  lack of vitamin B were probably also factors in his hair loss). He  was completely bald by the time he arrived in Mexico. Once on  location, Bogart started taking vitamin B shots, and some of his  hair grew back. But he did sport a wig throughout the entire shoot,  albeit one that was artfully muddied and matted to cover up the  joins.