Optimi Health’s Phase 2 depression study won’t dose anyone until 2027. A bill now in the House could shape whether mushroom-derived drugs like it are worth taking through the FDA.
Health Canada has authorized Vancouver-based Optimi Health to run a multisite Phase 2 trial testing a single supervised dose of naturally derived psilocybin in up to 200 adults with major depressive disorder (MDD), the company announced on September 10. The trial is scheduled to begin in the first half of 2027, with dosing expected to finish by year end. The primary efficacy endpoint is change from baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS).
A clinical trial authorization lets Optimi run a study. It does not approve Optimi’s product or widen patient access. Canadian patients outside of research generally reach psilocybin through Health Canada’s Special Access Program, which Optimi already supplies. The company’s 5 mg capsules have also been prescribed in Australia for treatment-resistant depression (TRD) since September 2025.
CEO Dane Stevens called the trial the company’s largest clinical commitment so far and “an initial step toward potential registration.” The announcement did not disclose the dose, the comparator arm, the number of sites, or the psychological support participants will receive. Six days later, Optimi announced a second Health Canada authorization, this one for a Phase 3 trial of MDMA-assisted therapy for PTSD in up to 100 veterans and frontline workers, using the company’s synthetic MDMA. Stevens said the goal is to submit both products for registration.
What “natural” means in Optimi’s case
Optimi grows its own mushrooms and extracts the active ingredient in-house at its GMP facility in Princeton, British Columbia. In May it reported a production run of extract measuring about 6% psilocybin, its highest concentration to date, and said the run kept the extract’s botanical profile intact at scale.
That puts the psilocybin program on a different track from the most advanced U.S. candidates. Compass Pathways’ COMP360 is a proprietary synthetic formulation, and the Usona Institute synthesizes its own. Natural psilocybin has its own supply base. Filament Health, now owned by Red Light Holland, says its botanical candidate PEX010 has been used in more than 80 studies and holds FDA and Health Canada authorization for a Phase 2 trial in stimulant use disorder. Optimi calls its study one of the largest trials of naturally derived psilocybin to date. Usona’s Phase 3 trial of synthetic psilocybin in MDD enrolled 238 participants.
The synthetic programs are also years ahead. Compass expects to complete its rolling new drug application for COMP360 in TRD in the fourth quarter and anticipates a launch in the first half of 2027, subject to FDA approval and Drug Enforcement Administration rescheduling. At the Morgan Stanley healthcare conference on September 16, executives said FDA inspections were set to begin that week. Usona holds an April national priority voucher for psilocybin in MDD, which targets a one- to two-month FDA review once an application is filed.
The bill
On August 27, Rep. Lauren Boebert (R-Colo.) introduced the Advancing Botanical Drug Development Act of 2026 (H.R. 10150) with Rep. Derrick Van Orden (R-Wis.) as its only cosponsor. The bill would give a botanical drug approved through a new drug application filed after enactment 12 years during which no generic or 505(b)(2) application relying on it could take effect. A new chemical entity currently gets five years. Twelve years is the period Congress set for biologics in 2010.
“Botanical drugs are FDA-approved medicines, not dietary supplements,” Boebert said in announcing the bill, arguing that a defined exclusivity period would support rigorous development without loosening FDA requirements. Few botanical drugs have been approved since the agency created its pathway in 2004. FDA’s own count is four.
The bill never mentions psilocybin or cannabis, and it leaves the most consequential question to regulators. It defines “botanical drug” as whatever the HHS Secretary determines by regulation. FDA’s current botanical definition covers macroscopic fungi, the category psilocybin mushrooms fall into, and excludes highly purified substances taken from natural sources. FDA’s final psychedelics guidance, issued in July, draws the same line. Under that reading, a mushroom extract with a broad chemical profile could qualify while purified psilocybin from mushrooms might not. Where Optimi’s extract or PEX010 lands would depend on rules HHS has not written. None of it would reach Optimi unless the company seeks U.S. approval, which it lists as a planned market pending federal rescheduling.
AJNA BioSciences, the Littleton, Colorado, company led by Charlotte’s Web co-founder Joel Stanley, is among the developers the bill would serve most directly. AJNA is developing AJA002, a full-spectrum psilocybin formulation for generalized anxiety disorder, and Stanley said in July that AJNA expected to file one or two more INDs this year.
H.R. 10150 sits with the House Energy and Commerce Committee, with one cosponsor and no action since its referral on August 27. Its exclusivity would reach only applications filed after the bill becomes law, and only products HHS defines as botanical. Compass expects to finish its filing by the end of this year. Optimi does not expect to finish dosing its psilocybin trial until the end of 2027.
