Bryan Johnson reports a high mold-spore count in his gym

On 25 September 2026, Bryan Johnson reported an air sample from his gym of 4,900 mold spores per cubic metre. He identified about 4,800 as Penicillium/Aspergillus and about 40 as Ulocladium, labelled the result “stage 4, high,” and gave an outdoor comparison of 360 spores per cubic metre. In a follow-up, he said he used a Buck BioAire B520, a calibrated-volume air sampler with a spore-trap cassette, followed by microscopic counting. The posts do not include the laboratory report, sample duration and placement, indoor conditions, independent confirmation, symptoms, or remediation results. This is a single-site environmental measurement, not a body biomarker or longevity experiment. Mikhaila Peterson replied that air sampling was a poor way to test for mold and suggested ERMI testing or swabs; her reply is recorded as public reaction, not verified evidence: https://x.com/MikhailaFuller/status/2103734711524933802. Johnson’s post does not report a health effect. The result does not establish exposure for other people or show that mold caused a clinical change.

“I found mold in my gym.”