X-Men: Apocalypse finally revealed how James McAvoy’s Professor Xavier lost his hair. While both X-Men: The Last Stand and X-Men Origins: Wolverine were financial successes, they were largely greeted with bad reviews and disappointment from audiences and fans alike. The franchise hit the reset button somewhat with 2011’s X-Men: First Class, a 1960s-set prequel that acted as an origin for the titular superhero team, in addition to showing how old friends/enemies Professor X (James McAvoy) and Magneto (Michael Fassbender) met.
First Class helped revive the reputation of the series, while 2014 sequel Days Of Future Past was one of the best received of the franchise. The Fox-era of the series has since come to an end, with the last outing of the First Class ensemble being 2019’s Dark Phoenix which, sadly, was a weak finale for the saga. The final official entry was The New Mutants, a long-delayed spinoff that also received a mixed reception.
The relationship between Professor Xavier and Magneto proved to be the beating heart of the prequels, with McAvoy being praised for his work – even in the lesser installments. Of course, McAvoy’s Xavier would eventually age into the Patrick Stewart version from the original movies, meaning there had to come a day where McAvoy’s Professor X had to lose his luscious head of hair. While he dropped a glib joke about going bald in First Class, it wasn’t until 2016’s X-Men: Apocalypse that the movies explained why he lost his hair, with Oscar Isaac’s mutant being to blame.
Part of the reason Apocalypse survived so long and became so powerful is that he could transfer his essence into another mutant. This also allowed him to gain new abilities, and in X-Men: Apocalypse, he settles on Charles Xavier as his new vessel. In the finale, he begins this transferrence process on Charles, and since this involves the host taking on Apocalypse’s physical appearance, Xavier’s hair falls out. Thankfully, the X-Men arrive in time to stop Apocalypse before the process is complete.
Unfortunately for Professor Xavier, his hair doesn’t grow back after this event, and from the ending of X-Men: Apocalypse onwards, James McAvoy’s Charles was bald. McAvoy had actually teased before the film’s release that Professor X would go through something so traumatic in the story he’d tear his own hair out, which seems to have been a gag on the actor’s part. The X-Men have yet to be introduced in the MCU but whoever follows both Stewart and McAvoy in the role, will have two tough acts to follow.