Athletes and fitness influencers use creatine, but what is it? And does it work?

The body naturally produces creatine in the liver, kidneys and pancreas, and it’s a quick fuel source for muscles. Photograph: bymuratdeniz/Getty Images

Creatine has long been popular among athletes. Olympians tout it, fitness influencers experiment with it, and Patrick Schwarzenegger’s gym bro character in The White Lotus added it to his famous shake.

It’s primarily considered a fitness supplement, but doctors are increasingly curious about its potential longevity and mental health benefits.