For a couple of years, longevity guru Bryan Johnson has touted rapamycin — approved by the Food and Drug Administration in 2015 as an immunosuppressant to aid organ transplants — as a “lifespan booster.”
Attendees of Johnson’s Don’t Die Summit in September in San Francisco exchanged information about where to source a prescription; online pharmacies like Ageless RX and Healthspan were the preferred choices.
But on Thursday, Johnson reversed his rapamycin rap, announcing on X that, after five years, he’d stopped taking the pills daily.
“Despite the immense potential … the benefits of lifelong dosing of rapamycin do not justify the hefty side-effects,” he wrote. These include soft tissue infections, lipid abnormalities, glucose elevations, increased resting heart rate, and “cancer risk in the longer run,” according to Johnson.
The most eye-popping claim in his post, however, was this: “Rapamycin [can] cause an increase/acceleration of aging in humans across 16 epigenetic aging clocks.” Johnson said this finding came from a preprint study from October without linking to it, but he appears to be referring to an analysis by scientists at Yale. The Standard was unable to reach the authors of the study or Johnson before publication.
Johnson’s far from the only one to wax lyrical about the drug’s cell-cleaning powers. Medical journal articles have assessed off-label uses of rapamycin as “a preventative therapy to maintain healthspan” and “the future of aging prevention,” while mainstream media outlets like the Washington Post and NPR have suggested the drug could be a “game changer.”
Johnson’s possible, accidental accelerated aging protocol has not hurt his status with the longevity crowd — they appreciate his honesty, said Mac McDonald, the Oakland-based founder of Try Met Rep, an AI-driven weight-loss startup.
McDonald has not tried rapamycin — he was worried about its potential to increase fat — but said Johnson’s willingness to share his blunder is part of his appeal. “It’s good that he updated [people] based on new information,” McDonald said. For longevity influencers, being upfront about whether body enhancement experiments work builds trust, he added.
Greg Mushen, vice president at Angi, a Thumbtack competitor, and founder of the Open Longevity Project, said he admires Johnson for his admission. “Sharing that personal data takes courage and really makes me respect him for doing it,” he said. “It’s not about being right or wrong, but rather being honest about what impacts you’re personally seeing on your body.”
Johnson’s saga with rapamycin is another reminder that longevity hacking is an evolving science. In the fight against dying, nothing is certain — except death itself.