Zac Efron trying stem cell therapy after suffering back injury

Zac Efron is using stem cell therapy after "messing up" his back while making a movie.

The Greatest Showman actor took to Instagram on Monday to share a photo of himself with Dr. Adeel Khan at Eterna Health.

In the accompanying caption, Zac shared that he sought advice from the medical professional after injuring himself on the set of the 2023 wrestling drama The Iron Claw.

"I fully commit to my roles, which I love, but it takes a toll - my back was messed up after The Iron Claw, even after months of PT (physical therapy)," he wrote. "Curious about stem cell therapy, I reached out to @dr.akhan at @eterna.health who answered all my questions and made me feel confident."

Zac went on to note that he has already noticed changes following the treatment.

"Now, six months post-treatment, I'm back in the gym and already seeing improvements," the 36-year-old continued.

According to the Eterna website, doctors at the clinic use mesenchymal stem cells (MSCs) in their treatments and claim they have "been engineered to augment their regenerative potential and evade detection by the immune system, thus improving their engraftment efficiency".

Zac concluded the post by noting he is "excited to explore the latest longevity technologies" and promised to update fans with his progress.

However, he did not indicate whether the post was part of an advertising campaign or partnership.

Zac has endured various health issues over the course of his career.

In 2013, he had to have his jaw wired shut after breaking it in a fall, while in August, he was rushed to hospital after he was found unconscious in a swimming pool in Ibiza.

At the time, US media outlets reported that the Hairspray star had aspirated a significant amount of water into his lungs but recovered quickly and discharged the following day.