On June 20, 2025, a U.S. Drug Enforcement Administration (DEA) Administrative Law Judge recently recommended classifying 2,5-Dimethoxy-4-Iodoamphetamine (DOI) and 2,5-Dimethoxy-4-Chloroamphetamine (DOC) as Schedule I substances. These compounds, which are currently not scheduled drugs listed in the Controlled Substances Act, are essential for studying the role of serotonin in various neurological disorders. The scientific community and drug policy reform advocates have strongly condemned this move because they argue that both are imperative for research. 

This decision, which coincided with both World Psychedelics Day and the final day of Psychedelic Science 2025, is viewed by those who previously challenged the DEA in court over this issue in 2024 as a direct attack on psychedelic research and a concerning precedent for scientific freedom. “It is not lost on us that the DEA Administrative Judge Paul E. Soeffing waited to issue his opinion until World Psychedelics Day,” said Robert Rush, attorney for Dr. Raul Ramos, a co-petitioner in the case.

Kat Murti, Executive Director of Students for Sensible Drug Policy (SSDP), echoed this sentiment in a press release in response to the recommendation. “The timing is no coincidence,” she said. “The DEA has relied on similar shady tricks throughout this process, such as announcing their intent to schedule these substances during the winter holidays in 2023 after withdrawing their 2022 attempt, which SSDP also opposed. Their strategy throughout has been to try to sneak by this ruling unnoticed because they know the American public and anyone who cares about public health is on our side.”

Scientists are fighting to keep DOI and DOC off the list of controlled substances because they are invaluable for investigating how serotonin impacts anxiety, depression, pain, substance use disorder, and even cancer. They have been used for decades in research in controlled settings without any indication of abuse or diversion.

DOI is particularly important in neuroscience research due to its high selectivity for the 5-HT2A serotonin receptor, a key brain protein involved in perception and mood. This receptor is crucial for understanding the therapeutic effects of psychedelics and has been instrumental in advancing psychiatric drug discovery, including mapping serotonin receptors in the brain linked to learning, memory, pain, and psychiatric illness. Currently, over 80% of antidepressant drugs target the serotonin system.

The DEA’s decision disregards extensive testimony given at the agency’s administrative court in Arlington, Virginia in November2024. SSDP-Ramos’ legal team called a long list of expert witnesses, many of whom are leading neuroscientists, chemists, and clinicians who rely on these compounds for advanced neuroscience research and experimentation. 

“Scientists ask questions about who we are, what we are, and how we are,” said Dr. Elijah Ullman, a researcher and molecular and systems pharmacologist, and the first person who initiated the fight to keep DOI and DOC legal back in 2022, to DoubleBlind in a statement. “In order to do that, we need tools for neuroscientists and pharmacologists like myself.”

“DOI is the most widely used chemical tool for studying the serotonin 2A and 2C receptors,” Dr Ullman continued, emphasizing that scheduling these drugs will hinder scientific progress. “Don’t you think it’s important to know how the most abundant serotonin receptor that’s involved in everything from cognition to mood works? Apparently, the DEA doesn’t.”

SSDP and its legal team contend the ruling is the result of a deeply flawed administrative process. One that’s keen on disregarding experts, data, and evidence, and upholding the prohibitory mission of the DEA at all costs. “The ruling rests on illogical conclusions, ignoring evidence presented by many of the world’s top experts, instead giving almost complete deference to the testimony of a single DEA scientist,” said Robert Rush, attorney for Dr. Raul Ramos. “The judge afforded excessive deference to the government’s witnesses, accepting their assertions without adequate scrutiny, while unjustifiably discounting the testimony of world-class researchers and experts who are at the forefront of psychedelic science. The evidence presented by our team was extensive and compelling, and was not afforded the weight it deserved.”

Dr. Alaina Jaster, a pharmacology and toxicology expert who served as an expert witness in the DOI and DOC case, found the decision baffling. “The decision ignores the logical and factual evidence we presented, simply because it challenges the rules and systems that the DEA currently operates within,” said Dr. Jaster. “The rules and terms that are used [by the DEA] are a decade behind the science and demonstrate the clear divide between those actually doing medical research and those who aim to regulate it. While I’m disappointed, this decision lends an even greater opportunity to build up our community of scientists and continue fighting for research to be accessible, respected, and understood.” 

Despite disagreements on much of the evidence, the DEA and SSDP-Ramos agreed on the fact that there is no diversion of DOI or DOC from legitimate channels, no evidence of physiological or psychological dependence, and no documentation in medical literature of human use or associated deaths. 

Despite initial attempts by the DEA to block expert testimony, Judge Soeffing permitted discussion of the potential harms to research and explicitly requested SSDP address the impact of a Schedule I designation in their post-trial brief. In response, SSDP proposed an updated 8-Factor Analysis incorporating all the harms to research, demonstrating that DOI and DOC lack characteristics associated with high abuse potential.

“We are using the law to bring science to the forefront, applying the best reading of the statute to ensure decisions align with empirical evidence. The science is so overwhelmingly in our favor that there’s only one logical way to rule on this case, regardless of how one views the Controlled Substances Act,” says Brett Phelps, Esq., an SSDP alum and member of the legal counsel. “It would fly in the face of logic to ignore the science.”

Judge Soeffing ultimately disregarded the overwhelming evidence and the fact that this decision could cause more harm to scientific research than good for the people. “The Judge acknowledged that the scheduling of DOI will cause harm to research, but held that this harm is irrelevant, Rush said. “Harm to research is not irrelevant — it is a threat to public health by shutting down critical research, including research involving tackling opioid addiction.” 

If DEA Administrator Terry Cole enacts the recommendation, it would have a significant impact on scientific freedom and public health.  DOI and DOC are essential research chemicals whose unscheduled status has made them de facto tools for researchers, like Dr. Tanner Andersen, SSDP Science Committee member and SSDP-Ramos co-petitioner, who is currently a postdoctoral researcher at Yale University.

“I have spent my entire PhD studying DOI,” said Dr. Anderson. “Placing DOI and DOC in Schedule I would be a step backward for neuroscience and public health…We rely so much on DOI in neuroscience research because it targets the psychedelic serotonin receptors in the brain much more precisely and with less off-target effects than other, more well-known psychedelics such as psilocybin or LSD…If DOI and DOC were banned, there is so much we now know about the brain that never would have been discovered, my work included.”

SSDP’s fight is a testament to the next generation of scientists leading advocacy roles and shaping policies. “If not for the young scientists and researchers in SSDP who bravely spoke truth to power and put their burgeoning careers on the line for what is right, DOI and DOC would have been scheduled in 2022,” said Murti, who vowed that SSDP will continue the fight in federal court in the weeks, months — and if necessary — year ahead.

“SSDP will not back down,” said Murti. “This battle is not over — we are committed to taking it to the next level and continuing to fight to keep not just psychedelic research but scientific and medical research writ large legal. Science is not a crime.”

💌 If you loved this email, forward it to a psychonaut in your life.

Editorial Process

DoubleBlind is a trusted resource for news, evidence-based education, and reporting on psychedelics. We work with leading medical professionals, scientific researchers, journalists, mycologists, indigenous stewards, and cultural pioneers. Read about our editorial policy and fact-checking process here.