Psilocybin’s effects on human cell and mouse aging; Cancer patients treated with psilocybin show decreased depression and anxiety symptoms

Plus: Colorado town debates natural medicine, New EU funding for psychedelics studies, and Alaska’s natural medicine ballot initiative

Happy Friday and welcome back to The Microdose, an independent journalism newsletter brought to you by the U.C. Berkeley Center for the Science of Psychedelics.

Psilocybin’s effects on cell and mouse aging

New results published in the Nature journal npj Aging suggest that psilocin, the active metabolite of psilocybin, could increase the lifespan of human cells — and that of mice, too. When treated with a 10 micromolar (μM) psilocin solution, the lifespan of human cells in culture was increased by 29%. The study’s authors, medical researchers from Emory and Baylor, then tried treating cell cultures with a ten-fold higher concentration of psilocin — 100 μM — and that increased cells’ lifespan by 57%. “Old” mice — 19 month olds, equivalent to roughly 60 human years of age — also lived longer after receiving 10 doses of psilocybin over 10 months. While only 50% of the control group of mice who did not receive psilocin lived to 28 months, 80% of mice who received psilocybin lived that additional 9 months, providing “the first experimental evidence demonstrating that psilocybin treatment can enhance survival in aged mice.”

Longevity enthusiasts and news sites alike hyped the results. Tech entrepreneur turned self-experimentation longevity guru Bryan Johnson posted about the results on X, saying, “I might have to try shrooms (for science).” "This surprising substance could be the key to living a longer life, study says,” claimed a New York Post headline. “This natural mushroom molecule could help you stay younger, longer,” Sports Illustrated wrote.

But there are several caveats worth noting about these studies. First: human cells and mice are, of course, not real live humans; there is not yet evidence that psilocybin or psilocin actually increase human lifespan. Moreover, it’s unclear what kind of dose would be necessary in humans to see such an effect, and how the dosing of mice in this study scales to humans.

Additionally, extending a human’s overall lifespan is much more complicated than extending the lifespan of human cells, and indeed, the authors of the study note that extending cellular lifespan could have other consequences, such as increased cancer risks. “Future research should rigorously assess the potential impacts of long-term psilocybin treatment in vivo on cancer incidence and/or progression. Few studies have evaluated the impacts of long-term prolonged dosing,” they write.

Two years later, cancer patients treated with psilocybin show decreased depression and anxiety symptoms

In 2020, researchers at Sunstone Therapies in Maryland gave 30 cancer patients a single dose of psilocybin, accompanied by group psychotherapy. Their results, published in Cancer, the American Cancer Society’s journal, in late 2023, found that a single 25-mg dose decreased participants’ depression and anxiety symptoms.

A new study, also in Cancer, followed up with participants two years after their treatment. Of those original 30 participants, two had died; of the remaining 28, 25 showed a significant decrease in depression symptoms two months after treatment, as measured by the MADRS, a standard depression questionnaire. By two years post-psilocybin, 15 continued showing a reduction in their depression scores compared to pre-psilocybin treatment. The scores of 14 of those 15 qualified as remission from depression.

That single dose of psilocybin also seemed to decrease participants’ anxiety symptoms in the long-term. In the initial two months after treatment, 22 of the 28 showed a continued reduction in anxiety; two years later, five of the 28 had decreased anxiety scores. Seventeen of 28 participants did not take any other psychedelics or antidepressants in the intervening years, but seven took antidepressants and three received more psychedelic treatment. Overall, the researchers write, “psilocybin may be an alternative to traditional antidepressants in providing long-term mental health treatment for patients with cancer.”

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Colorado town debates natural medicine

At a meeting Tuesday evening, the city of Salida, Colorado debated how to implement Colorado’s Natural Medicine Program locally. In January, the city passed an emergency ordinance that enacted a temporary moratorium on natural medicine, which was set to expire in July. In June, the council voted again to extend that moratorium to mid-August. In another June meeting, the city’s planning commission voted to require all applications for natural medicine businesses to be reviewed by the commission.

Ahead of the July 15 meeting, the city attorney recommended against the city council adopting the planning commission’s amendments, writing in a memo that requiring reviews of each natural medicine business “will result in unnecessary paperwork, backlog, and workload” for city staff. In the end, the council voted unanimously to accept the city attorney’s office’s recommendations, but the mishmash of proceedings in Salida demonstrate that some Colorado municipalities are reluctant to allow psilocybin businesses into the area without local review.

New EU funding for psychedelics studies

The European Union’s Marie Skłodowska-Curie Actions, a set of programs that provide funding for doctoral and postdoctoral research and training, will dedicate 4.3 million euros towards training the next generation of psychedelics researchers, according to an announcement by psychedelics advocates. The Interdisciplinary Network for Training, Education, and Growing Research into Applications of and Therapeutic Expertise around Psychedelics — or INTEGRATE — will fund 16 doctoral candidates across all fields of study, from neuroscience to law. At a time when the U.S. government is making significant cuts to basic research and training graduate students in the sciences, the EU’s investments in research could position it as a growing powerhouse for psychedelic studies.

Alaska’s natural medicine ballot initiative

Last month, activists in Alaska submitted a petition to the state for a ballot initiative modeled on Colorado’s Natural Medicine Program. It proposes the decriminalization of natural medicine in the state, along with the launch of a state-regulated access program. To submit the petition, organizers collected 200+ signatures in support of the initiative. If the ballot measure is approved by state regulators by mid August, the initiative’s organizers have until January 2026 to collect roughly 34,000 signatures (10% of those who voted in the preceding general election) to qualify for the 2026 ballot.

• On Monday, U.S. representatives Lou Correa (D) and Jack Bergman (R), co-chairs of the Congressional Psychedelic Advancing Therapies (PATH) Caucus, met with Veterans Affairs Secretary Doug Collins to discuss the advancement of psychedelic-assisted therapy research and the Innovative Therapies Centers of Excellence Act, a bill the PATH caucus introduced earlier this year to increase funding for psychedelics studies.

• The Sonoran Desert toad — whose secretions contain 5-MeO-DMT — are under threat. For The New York Times, science journalist Rachel Nuwer interviews researchers studying their plight.

• MAPS has begun releasing recordings from sessions at Psychedelic Science 2025.

• Fox News interviews Bryan Hubbard about what Americans should know about ibogaine.

You’re all caught up! We’ll be back in your inbox on Monday with a new issue of 5 Questions.

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