Arnold Schwarzenegger is urging people to use supplements more cautiously. According to his July 8, 2026 newsletter, Arnold’s Pump Club, there is one major cause of heavy metal contamination in creatine supplements that has nothing to do with the creatine.

Schwarzenegger opened the newsletter by noting that creatine carries over 600 human trials behind it, then posed the question most buyers skip at checkout: "What else made it into the tub along with it?"

He went straight to the source of the problem. "Contamination in creatine mostly doesn't come from the creatine," he wrote, adding that researchers tracing contaminants in commercial products "point to a specific list of culprits, and most of them are not the ingredient itself."

From there, Schwarzenegger named names. "The metal tubing and equipment the powder passes through on the production line," he said, are the likely sources of mercury and cadmium, two metals he said turn up mainly "because they're used in plastics manufacturing."

The warning comes from an avid health advocate who has spent almost all his life building his own health and inspiring others. Schwarzenegger is not against creatine; in fact, he says it is one of the most studied supplements, calling it a low-risk, high-reward supplement.

He also used his newsletter to credit creatine with many health benefits, including muscle gain, fat loss, recovery from sleep deprivation, and improved cognitive performance.

Schwarzenegger has previously used the newsletter to refute theories linking creatine to bloating and hair loss.

Where Arnold Schwarzenegger Says the Contamination Actually Comes From

For Arnold Schwarzenegger, it’s not the supplement he disapproves of but the supply chain and the people behind it.

That was a line he drew once before; for example, in his January 2025 letter discussing protein powder contamination, he proposed using third-party-tested supplements rather than abandoning supplementation altogether.

This coming from someone like Schwarzenegger, who has taken creatine for years, this should be a major criterion when shopping for supplements.

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Written by

Proma Chatterjee

Edited by

Ashvinkumar Patil