Psilocybin made human cells live 50% longer. A new study has uncovered surprising anti-aging potential in psilocin—the active metabolite produced when the body breaks down psilocybin, the psychoactive compound found in magic mushrooms. In laboratory experiments, researchers exposed two human cell lines (skin fibroblasts and fetal lung fibroblasts) to a 100 μM concentration of psilocin. The results were striking: lung cells took 57% longer to reach replicative senescence (the point at which cells permanently stop dividing and accumulate damage), while skin fibroblasts extended their replicative lifespan by 51%. These findings suggest psilocin may slow fundamental cellular aging processes, possibly by lowering oxidative stress, enhancing DNA-repair pathways, supporting mitochondrial health, or dampening chronic inflammation—mechanisms that overlap with those targeted by leading experimental longevity drugs. The benefits extended beyond cell culture. In aged female mice (19 months old at the start, equivalent to approximately 60–65 human years), a single monthly dose of psilocybin dramatically improved outcomes. After 10 months of treatment, 80% of the psilocybin-treated animals remained alive, compared with only 50% of untreated controls. Treated mice also displayed markedly fewer visible signs of aging, including reduced fur loss and graying. This research marks the first direct demonstration that psilocybin/psilocin can influence biological aging itself, rather than solely producing psychological effects. The authors emphasize that the study used relatively conservative dosing and are now advocating for follow-up work with higher or more frequent administration, detailed assessments of immune, metabolic, and cognitive function, and investigations into whether the extended lifespan corresponds to genuine improvements in healthspan and quality of life. ["Psilocybin treatment extends cellular lifespan and improves survival of aged mice." npj Aging, 2025]