20/11/2025
Bryan Johnson just did something pretty unusual, even for him. He took 5 grams of psilocybin mushrooms and tracked his brain activity in real time with high-end imaging tech.
The whole idea was to see whether the mental shifts from psychedelics could matter for longevity in the same way people obsess over telomeres and senescent cells.
As soon as the mushrooms kicked in, his brain changed dramatically. The prefrontal cortex, which normally keeps you organised and restrained, quieted down. At the same time, sensory and motor regions lit up. His inner narrator softened.
And what he felt matched the data. He described his consciousness at “10 out of 10,” found himself fixated on light in a jar, and said touch and taste felt explosive.
The science behind it is surprisingly consistent with what we know. Psilocybin becomes psilocin in the body, which activates 5-HT₂A receptors in the cortex. When those receptors fire, your brain shifts from a rigid top-down hierarchy to something far more flexible and exploratory.
Connectivity increases in unusual places, entropy rises, and the brain becomes more childlike in how it processes the world. Johnson’s scans lined up almost perfectly with the known distribution of these receptors, which made the results even more interesting.
At the peak, his brain was in full sensory overdrive. His prefrontal cortex was still dialed down, and raw sensory information poured through. Everything became vivid and significant. He felt hyper aware, hyper alive, and completely captivated by simple sensations. He did not experience full ego dissolution, which tends to require a higher dose, but he hit a state that clearly disrupted his usual patterns. As he came down, the trip shifted.
His prefrontal cortex slowly regained function, and the Default Mode Network began reappearing. His inner experience followed that arc too, moving from pure sensation into philosophical reflection about life, death, and the future of humanity.
The next morning, the afterglow was still present in both his brain and his behaviour. His senses remained sharper. His speech and creativity networks were still more active than baseline. His default mode network was still partially suppressed.
Emotionally, he felt clear, open, humorous, and energised. This afterglow effect is common with psychedelics, but seeing it visually mapped adds a new layer. For Johnson, the experience felt like a temporary return to “factory settings,” undoing some of the numbness that creeps in with age.
Where he takes it next is the longevity angle. There is good evidence that happiness, optimism, and purpose reduce mortality risk. There is also early data that psychedelics can reverse biological age markers and may slow cellular ageing.
Johnson is connecting the dots, suggesting that ageing is not only about cells breaking down but also about the mind becoming narrow, predictable, and less curious. If psychedelics can temporarily dissolve those patterns, maybe they help you stay mentally young in a way that influences physical health too.
He is still measuring his brain daily to see how long these shifts last. Whether or not mushrooms become a legitimate longevity tool is still unknown, but this experiment highlights something important. His subjective experience and brain imaging matched almost perfectly. His mind felt younger, more alive, and more open, and his brain literally reflected that.
Even if you ignore the longevity angle, the study offers a rare window into how consciousness changes when the filters of adulthood momentarily drop away. Pretty fascinating stuff.
