The "Kingsman: The Secret Service" star plays the British rock legend in new biopic "Rocketman", and to really transform into the singer during his youth, Taron reluctantly allowed the film's hairstylists to mess with his widow's peak.
"I can remember the day we first did those things to my hair," he tells E! News. "For the '70s period of the film, we used my own hair in the hope of achieving something very natural. We dyed my hair, we thinned it out, and we shaved my hairline up further than it already is."
Although Taron wasn't happy with his disappearing hairline, he admits the simple style change really helped him complete the cosmetic transformation into Sir Elton.
"It was great really," he says. "I found something quite exciting about transforming the way you look a bit, especially as an actor, because it makes you feel different. So whilst I didn't relish having my forehead bicked (shaved) every day, because I was worried it wouldn't grow back, it works really well in the movie."
Off set, Taron made sure to keep a hat on hand at all times to hide his fake thinning locks.
"(I) was under a hat all year," he laughs, "which is sort of fine a lot of the time, but it's a bit of a pain when you're going to dinner or something, but it's alright. What can you say? It's all for the art!"
Taron wasn't the only one to feel a little uncomfortable on set - his co-star Richard Madden, who plays Elton's former manager and lover John Reid, battled self-confidence issues throughout the movie musical.
"There's nothing more terrifying... I felt naked when (I) sing and dance. You're kind of showing different things and I was really terrified of it," the former "Game of Thrones" actor shares. "I worked really hard to try and make sure that I wasn't thinking about my singing voice on the day (of filming). I was thinking about the storytelling instead."