The U.S. Drug Enforcement Administration has argued that two important research chemicals, 2,5-dimethoxy-4-iodoamphetamine (DOI) and 2,5-dimethoxy-4-chloroamphetamine (DOC), should be classified as Schedule I, but how common are these compounds outside of the lab?

A new epidemiological review authored by Joseph Palamar, PhD* (NYU Grossman School of Medicine) and Nicole Fitzgerald, PhD (Columbia University), offers a clear answer: hardly anyone is using these drugs recreationally. 

*Professor Palamar was one of many expert witnesses who testified at DEA headquarters in November, 2024, during SSDP’s legal battle to keep DOI and DOC out of Schedule I. To read his full testimony, click here.

Published in the Journal of Psychoactive Drugs (2025), “The Epidemiology of Recreational Use and Availability of DOC and DOI in the United States” examines nearly two decades of data from forensic labs, national drugs use surveys, poison control records, and law enforcement seizure data. Across every dataset, the same conclusion emerges: the recreational use of DOC and DOI are exceptionally rare. 

From 2005 to 2024, the National Forensic Laboratory Information System, a DEA database that collects drug identification data from across the US, recorded 795 cases testing positive for DOC, peaking at 152 in 2012 before plummeting to just two detections in 2023–2024. Over the same period, only 40 samples tested positive for DOI, with none detected after 2019. By comparison, in 2023 alone, U.S. labs logged over 160,000 fentanyl detections in NFLIS. 

Between 2017 and 2024, the High Intensity Drug Trafficking Areas (HIDTA) program recorded only three DOC seizures, all in Washington state, and none for DOI. Meanwhile, in 2023, more than 23,000 HIDTA seizures tested positive for fentanyl. 

Survey data also confirms that DOC and DOI are not being used in significant numbers. In the National Survey on Drug Use and Health (NSDUH), which includes open-ended responses for uncommon drugs, only 37 respondents ever mentioned DOC and only 10 mentioned DOI between 2005 and 2023, representing a lifetime prevalence of less than 0.01%.

Among populations known for higher rates of drug use, such as New York City nightclub and festival attendees, the numbers were just as small. Across eight years of surveys, past-year DOC use ranged from 0% to 0.4%, and willingness to try it if offered peaked at only 0.8%. DOI use was so rare that researchers eventually dropped it from the survey.

In a separate nationwide study from the National Drug Early Warning System (NDEWS), only 0.02% of respondents reported using DOC in the past year. The system’s network of drug-checking sites and field researchers found virtually no evidence of DOI use anywhere in the country.

By and large, survey data indicates the DOC and DOI use is rare. In comparison, NSDUH estimated that 14.9% of individuals aged 12 years or older have used cocaine in their lifetime, and 1.8% used in the past year. 

One of the most striking findings of this review is the lack of substantial poisoning and fatalities associated with DOI and DOC. In 16 years of U.S. poison center and toxicology data, researchers found only one confirmed fatality involving DOC (in 2012) and none involving DOI. The scientific literature contained just three reports of DOC-related poisonings worldwide since 2008, mostly in cases where the drug was mistaken for LSD. Similarly, the Center for Forensic Science Research and Education reported that no forensic samples tested positive for DOC or DOI between 2015 and 2024. 

These findings confirm what we already knew: these substances pose no significant threat to public health given their near-total absence from the illicit market. If they are used at all, it “is by a unique population called psychonauts, and that most other use is unintentional.”

It is clear then that the decision to put DOI and DOC in Schedule I will help no one, since these drugs are not used by the public. On the contrary, it will impact scientific researchers working with these compounds in hugely negative ways. In the words of the authors: “the scheduling of DOI specifically will also adversely affect serotonin receptor research.”

To read Professor Palamar’s testimony from SSDP’s November 2024 court hearing against the DEA to keep DOI and DOC out of Schedule I visit our blog.