Washington's psilocybin study nears its finish line as legalization bills stall

When Washington lawmakers passed their first psilocybin law in 2023, they chose to study it before legalizing it. Three years later, the study is nearly done collecting its main results, and the legalization side hasn't moved.

The study

The 2023 law, 2SSB 5263, directed the University of Washington to run a pilot of psilocybin therapy for adults 21 and older, for populations including first responders and veterans. The result, PsiloStudy, is run by UW's Center for Novel Therapeutics in Addiction Psychiatry and led by psychiatrist Nathan Sackett. According to its ClinicalTrials.gov listing, it's a Phase 2 trial of psilocybin with psychological support designed for about 40 military veterans and first responders who have both PTSD and alcohol use disorder. It started in June 2025, is no longer recruiting, and lists November 2026 as its estimated primary completion date, the point when data for its main outcome should be in. Published results typically take longer.

The same law created a state task force, which reported in December 2023 without recommending for or against legalization. Governor Jay Inslee vetoed the parts of the bill that would have set up a standing advisory board.

The bills

Sen. Jesse Salomon, the 2023 law's prime sponsor, has led every effort since:

• SB 5201 (2025) would have created supervised adult-use psilocybin services overseen by the Department of Health and the Liquor and Cannabis Board. It left the Senate health committee without a recommendation in February 2025 and stalled in Labor & Commerce. Its House companion, HB 1433, also stayed in committee.
• SB 5921 (2026) took a narrower, medical approach: a Department of Health program in which licensed clinicians could prescribe psilocybin to adults 18 and older with qualifying conditions, starting July 1, 2028. At its January 27 hearing, sign-ins ran heavily against it. It passed the Senate Health & Long-Term Care Committee on February 3 and was referred to Ways & Means, where it stalled.

With the 2026 session over, all three bills died with the 2025–26 biennium. Any new attempt starts from scratch when the Legislature convenes in January 2027. No psychedelics initiative qualified for Washington's November 2026 ballot.

Salomon has also pushed for ibogaine research. The state funded a $250,000 UW-led observational study of patients treated at an ibogaine clinic in Mexico in 2024, and The Stranger reported in January 2026 that his effort to go further had stalled.

Meanwhile, locally

With the state stuck, local governments have kept passing low-priority policies: Olympia in 2024, Tacoma in January 2025, and a King County Council motion in March 2026. None of them changes state law. Our Washington law guide tracks each bill and resolution.

What to watch

• Whether PsiloStudy meets its November 2026 primary completion estimate, and when results are published.
• Whether a psilocybin bill is filed for the 2027 session, and in what form.
• Federal action. If the FDA approves a psilocybin medicine and the DEA reschedules it, Washington's controlled substances law has the state follow a federal rescheduling within 30 days unless someone objects (RCW 69.50.201). We covered that timeline here.

Last checked against the sources above on Oct 20, 2026. Spotted something out of date? Tell us.