, updated
Oregon proposes changing the formula labs use to total psilocybin potency
Oregon has proposed that psilocybin testing labs stop reporting "total potential psilocin" and report a "total psilocybin equivalent" instead. The notice was filed on September 30, the public hearing was held on October 19, and the comment period ran until October 21, 2026.
What the proposed rule changes
The Oregon Health Authority (OHA) filed a notice of proposed rulemaking on September 30, 2026 for OAR 333-007 and 333-064, the lab testing rules that cover marijuana, hemp and psilocybin.1 For psilocybin, the notice changes "the definition and calculation for 'total potential psilocin' to 'total psilocybin equivalent'" and updates the definition of "homogenization".1
The formula sits in OAR 333-064-0150. Lab reports would still list psilocybin and psilocin separately, in milligrams per gram. Only the combined figure changes.1
| Figure | Formula | Counts everything as |
|---|---|---|
| Total potential psilocin (Oregon now) | psilocin + 0.719 × psilocybin | Psilocin |
| Total psilocybin equivalent (Oregon proposal) | psilocybin + 1.4 × psilocin | Psilocybin |
| Total Psilocin (Colorado) | psilocybin × 0.719 + psilocin | Psilocin |
Why two formulas give two different numbers
Psilocybin is turned into psilocin in the body after it's swallowed.4 The 0.719 factor is the ratio of their molar masses (204.27 for psilocin, 284.25 for psilocybin, per PubChem), so it converts psilocybin into the most psilocin it could become.56 The proposed formula works the other way round: it multiplies psilocin by 1.4, close to the inverse of 0.719, and expresses the total as psilocybin. Our page on psilocybin vs psilocin explains the chemistry.
Oregon's current rule calls total potential psilocin "the maximum theoretical concentration of psilocin in the sample".2 OHA's separate draft program rules describe the new figure as "the maximum theoretical concentration of psilocybin in the sample".7
Nothing in the mushroom changes. By our arithmetic from the two formulas, the new total for the same product comes out about 1.39 to 1.4 times the old one, because the reference molecule switches from the lighter psilocin to the heavier psilocybin.
Why Oregon is making the switch
The notice lists the Oregon Psilocybin Services (OPS) "2026 Psilocybin Product Potency Workgroup" as a document it relied on.1 OPS convened that group on March 3, 2026 after "licensees shared concerns regarding psilocybin products with high psilocin content being used for lower dose administration sessions". Its stated purpose was to consider potency formulas "including 'total psilocybin equivalent'" and "safety issues related to the use of high-psilocin products". A planned second meeting was dropped.8
OHA's fiscal statement says licensees "may incur cost for changing labels from 'total potential psilocin' to 'total psilocybin equivalent'".1
License fees are not part of this rule. OHA had separately proposed psilocybin license fee increases from January 1, 2027, then said it "will not adopt the proposed fee increases".9
Why it matters if you read potency numbers
A "total" milligram figure means little until you know which formula produced it. The same mushroom reads about 40% higher in psilocybin terms than in psilocin terms, so two labels or lab reports can disagree without either being wrong.
States are also splitting. Colorado labels regulated products in Total Psilocin.3 Oregon proposes psilocybin terms.1 New Mexico's producer rule would print both totals on the label.10 When a label, seller or calculator quotes one potency number without naming its basis, there's no way to tell which of these it is. Our guide to what capsule labels measure walks through the other questions to ask of a label.
Sources
- Notice of proposed rulemaking, OAR 333-007 and 333-064 (marijuana, hemp and psilocybin testing). Oregon Health Authority, filed September 30, 2026.
- OAR chapter 333, division 64 (OAR 333-064-0025 and 333-064-0150). Oregon Secretary of State, retrieved October 26, 2026.
- 1 CCR 213-1, Natural Medicine rules, Rule 1025 definitions. Colorado Department of Revenue, version effective August 12, 2026.
- Otto ME, et al. Clinical pharmacokinetics of psilocin after psilocybin administration: a systematic review and post-hoc analysis. Clin Pharmacokinet, 2025;64(1):53-66. PMID 39812743.
- Psilocybin (CID 10624). PubChem, National Library of Medicine, retrieved October 26, 2026.
- Psilocin (CID 4980). PubChem, National Library of Medicine, retrieved October 26, 2026.
- Draft OAR 333-333 rules for the November 2026 rules advisory committee. Oregon Health Authority, October 2026.
- 2026 Psilocybin Product Potency Workgroup. Oregon Psilocybin Services, Oregon Health Authority, 2026.
- Psilocybin administrative rules. Oregon Health Authority, retrieved October 26, 2026.
- Proposed 7.35.2 NMAC, Medical Psilocybin Producer and Laboratory Requirements, rule text and exhibits. New Mexico Department of Health, 2026.
Keep reading
Oregon's draft psilocybin rules add a new potency line to product labelsOregon's draft rules add a total psilocybin equivalent label line and, under HB 4040, split dose reporting.
Psilocybin vs psilocin: what's the difference?One is the stored form, the other the active one: the chemistry behind lab reports and blue bruises.
What does the mg on a mushroom capsule label mean?Powder weight, psilocybin or total psilocin? How to read a label and the batch lab report behind it.
Written and checked by the Dosage Calculator editors. Every figure on this page links to its source. Found an error? Tell us and we'll correct it in the open, as our editorial standards describe. Magic Mushroom Dosage Calculator is published by the team that runs My Mushroom Dispensary, an online shop. We sell no advertising and nothing on this site.