"I’m a natural blonde," he said. "It gets dyed. It’s pretty horrific. I have to get it dyed a crazy amount — it’s like every three weeks. It’s not easy. It’s hard being a ginger. But I think everybody has a little bit of ginger in them. I’ve got some in my beard." He recently cut his hair short for a movie role, he added, but now that he's back on Outlander, it's back to the old routine.
Other celebs have confirmed that dying your hair red for a role is no easy feat. Ariana Grande wrote in a since-deleted Instagram post that she had to dye her hair red "every other week" for years for Nickelodeon's Victorious and Sam & Cat. Her hair got so damaged that she had to wear extensions and keep it in a ponytail until it grew out. The "actual hair is so broken that it looks absolutely ratchet and absurd," she wrote, according to The Huffington Post.
KJ Apa similarly told Vulture he has to dye his hair "every two weeks" for Riverdale. "It’s not my favourite thing to do, but obviously I’ve got to do it because the roots keep coming up and my hair grows really fast," he said. The bleach used on his eyebrows once actually burned holes in his skin.
While hair dye can contain chemicals that may dry out your hair or cause breakage, the bleach is the real culprit. If you're going to bleach your hair, you can lessen the damage by using conditioning masks and refraining from washing your hair beforehand. But as most actors who constantly have to bleach their hair for roles could tell you, some damage is pretty much inevitable.