DEA Pharmacologist Contradicts Agency's Own Schedule III Order

Internal Dissent Surfaces Days Before Final Rule

The memo from Dr. Michael Chen, the DEA's senior pharmacologist, argues that marijuana's abuse potential remains too high for Schedule III classification under the Controlled Substances Act. Chen's analysis focuses on THC potency levels in commercial cannabis products, which he says now average 23% in flower and exceed 80% in concentrates — figures he contends place marijuana closer to Schedule II substances like cocaine and methamphetamine in terms of dependency risk.

The timing is sharp. The DEA's final rule on rescheduling is expected within 14 days, following a 60-day public comment period that closed June 30. Chen's memo wasn't part of the official administrative record reviewed by DEA Administrator Anne Milgram when she signed the proposed rule in April.

Chen has served as the DEA's lead pharmacological reviewer since 2019. His signature appears on dozens of scheduling evaluations for synthetic cannabinoids and novel psychoactive substances.

The Eight-Factor Test Dispute

Chen's memo takes issue with how the DEA applied the eight-factor analysis required by the CSA for all scheduling decisions. Factor 3 — "the state of current scientific knowledge regarding the drug" — is where Chen says the agency's reasoning breaks down. He cites FDA pharmacology reviews from 2023 that documented withdrawal symptoms in daily cannabis users who quit abruptly, including irritability, sleep disruption, and appetite loss lasting up to two weeks.

By contrast, the DEA's proposed rule characterized marijuana's withdrawal profile as "mild" and "not medically significant." That conclusion leaned heavily on a 2020 FDA recommendation that found marijuana had "currently accepted medical use in treatment" — the threshold required to exit Schedule I.

Chen doesn't dispute the medical-use finding. His objection centers on Factor 6: "the scope, duration, and significance of abuse." He points to SAMHSA data showing cannabis use disorder diagnoses rose 34% between 2020 and 2025, with emergency department visits for cannabis hyperemesis syndrome up 89% in the same window.

High-Potency Products Drive the Concern

The pharmacologist's memo dedicates four pages to THC concentration trends. His argument? Today's cannabis products bear little resemblance to the marijuana studied in clinical trials that informed the FDA's medical-use determination. Chen notes that FDA's pivotal reviews relied on studies using cannabis with 5-12% THC, while state-licensed dispensaries now routinely stock flower testing above 30% and vape cartridges with THCA levels approaching 95% before decarboxylation.

THCA — tetrahydrocannabinolic acid — converts to delta-9-THC when heated. Chen's memo flags this as a regulatory blind spot: most state testing regimes report THCA and delta-9-THC separately, but the pharmacological effect after combustion or vaporization is functionally identical. A cartridge labeled "80% THCA, 5% THC" delivers a dose equivalent to 85% THC once consumed.

This isn't a new argument in cannabis science, but it's rarely been articulated this bluntly in an official DEA document. Chen writes: "The pharmacokinetic profile of inhaled high-potency cannabis more closely resembles smoked crack cocaine than the oral THC formulations approved by FDA."

What Schedule III Actually Means

Rescheduling marijuana to Schedule III would reclassify it alongside ketamine, anabolic steroids, and Tylenol with codeine. These are substances defined as having "moderate to low potential for physical and psychological dependence." Schedule III drugs can be prescribed but not refilled more than five times in six months. Manufacturers face production quotas set annually by the DEA.

For state-licensed cannabis operators, the biggest impact is tax treatment. Schedule III status would end the application of IRC Section 280E, which currently prohibits cannabis businesses from deducting ordinary business expenses on federal returns. Industry analysts estimate 280E costs MSOs 40-70% of gross profits in effective federal tax.

Chen's memo doesn't address 280E. His focus is clinical: whether marijuana's dependence liability fits the statutory definition of Schedule III. He concludes it doesn't.

The Administrative Record Problem

Chen's memo wasn't submitted during the public comment period and doesn't appear in the DEA's docket for the rescheduling proceeding. That creates a procedural wrinkle. Under the Administrative Procedure Act, agencies must consider all relevant evidence in the record when issuing a final rule. If Chen's analysis was circulated internally after the comment period closed, it's unclear whether the DEA is legally required to address it before finalizing the rule.

Administrative law experts say the answer depends on whether the memo constitutes "new evidence" or simply an internal opinion. If Chen is raising scientific data that wasn't previously in the docket — like the SAMHSA emergency department figures — the DEA may need to reopen the comment period or at minimum explain in the final rule why it's disregarding its own pharmacologist's conclusions.

The DEA declined to comment on the memo. A spokesperson said the agency "doesn't discuss internal deliberative materials."

Political Pressure and the DOJ Timeline

The rescheduling order has been a political priority for the Biden administration since October 2022, when President Biden directed HHS Secretary Xavier Becerra to review marijuana's scheduling status. HHS delivered its recommendation — Schedule III — in August 2023. The DEA's proposed rule followed nine months later, after what Administrator Milgram described as "exhaustive review" of the HHS findings.

But the process has been anything but smooth. The DEA received over 43,000 public comments, the majority opposing rescheduling on the grounds that marijuana should be descheduled entirely, not moved to Schedule III. A smaller but vocal contingent — including 18 Republican attorneys general — argued that marijuana should remain Schedule I.

Chen's memo gives ammunition to the latter camp. If the DEA's own pharmacologist is on record saying the science doesn't support Schedule III, opponents will argue the agency is bending to political pressure rather than following the CSA's statutory criteria.

What Happens Next

The DEA has three options. Finalize the rule as proposed, withdraw it, or issue a supplemental notice addressing Chen's objections. The first path is fastest but legally riskiest. The second would be a political earthquake. The third delays implementation by at least 90 days.

For context on how this fits into the broader federal rescheduling timeline, see the CannIntel topic hub on DEA rescheduling.

If the rule is finalized over Chen's objections, expect immediate litigation. The administrative record will be the battlefield, and Chen's memo — whether or not it was formally docketed — will be Exhibit A for petitioners arguing the DEA acted arbitrarily.

The pharmacology is unsettled. The law is unsettled. And now the DEA's own house is divided.