HHS, senators request DEA reschedule marijuana

Pressure mounts to ease restrictions on marijuana use and research

Legislators are seeking to remove marijuana from the Controlled Substances Act (CSA) after the U.S. Department of Health and Human Services (HHS) recommended that it be controlled in the Schedule III rather than the current Schedule I, the most restrictive CSA category.

In a January 29 letter to the Drug Enforcement Administration (DEA) and Biden administration, 12 Democratic senators, including Senate Majority Leader Chuck Schumer, cited the HHS’s determination—through the Food and Drug Administration (FDA) and National Institute on Drug Abuse (NIDA)—that marijuana meets the three criteria for placing a substance in Schedule III of the CSA, which are as follows:

  • Has a potential for abuse less than Schedule I or II drugs.
  • Has a currently accepted medical use in treatment in the U.S.
  • Its abuse may lead to moderate or low physical dependence or high psychological dependence.

The senators’ request went farther than the HHS, however, arguing that marijuana didn’t belong on the list of controlled substances. The group requested that the DEA respond by mid-February as to the status of its determination of marijuana’s scheduling.

Legal landscape

Marijuana refers to the dried leaves, flowers, stems, and seeds from the Cannabis spp plant, which contain over 80 different naturally occurring compounds called cannabinoids. Delta-9 tetrahydrocannabinol (Δ-9 THC) is one of 104 cannabinoids identified in marijuana and the substance responsible for the psychotropic experience in human users.

Marijuana has been classified as Schedule I since the CSA list was created in 1970. Schedule I classification means the drug has a high potential for abuse, no currently accepted medical use in treatment in the U.S., and a lack of accepted safety for use under medical supervision. Included in the Schedule I category are heroin, ecstasy, and LSD.

Receiving government approval for a research project involving a Schedule I drug is a daunting process requiring various levels of federal and state approval.

A cannabis researcher in nightshift checks a cannabis flower in a lab farm greenhouse
The Department of Health and Human Services has recommended that marijuana be moved to Schedule III of the Controlled Substances Act. If the Drug Enforcement Administration allows this to happen, Dr. Joseph Wakshlag, a professor in the Department of Clinical Sciences at Cornell University College of Veterinary Medicine, says it will “open the door” to additional veterinary research in this area.

The Food and Drug Administration (FDA) regulates products containing cannabis or cannabis-derived compounds marketed as food or drugs. In 2018, the FDA approved Epidiolex, the nation's first drug derived from marijuana, for the treatment of seizures associated with two rare and severe forms of epilepsy in humans. Since then, the agency has approved three synthetic cannabis-related drug products: Marinol (dronabinol), Syndros (dronabinol), and Cesamet (nabilone) for humans.

The FDA says it “supports sound, scientifically-based research into the medicinal uses of drug products containing cannabis or cannabis-derived compounds and will continue to work with companies interested in bringing safe, effective, and quality products to market.”

States started breaking with the federal government’s position on the drug in the 1990s when the marijuana decriminalization movement began. Since then, 38 states and Washington, D.C., have legalized marijuana use in some form, of which 24 allow the drug to be used recreationally.

The Agriculture Improvement Act of 2018 removed hemp—cannabis or derivatives of cannabis with a very low Δ-9 THC content (below 0.3% by dry weight)—from the CSA’s definition of marijuana, making hemp no longer a controlled substance under federal law.

Research opportunities

In 2022, the Biden administration directed the HHS and U.S. attorney general to conduct a review of how marijuana is scheduled under federal law. The HHS was tasked with conducting a medical and scientific evaluation for botanical cannabis (Cannabis sativa L.) and to report its findings to DEA, which will make the final scheduling determination.

In late January, as the review process was still ongoing, the HHS’s 250-page scientific assessment was leaked and published by news outlets online. Dr. Rachel Levine, the assistant secretary for the HHS, wrote in the report to the DEA: “Based on my review of the evidence and FDA’s recommendation, it is my recommendation as the Assistant Secretary for Health that marijuana should be placed in Schedule III of the CSA.”

The recommendation comes after the FDA considered eight factors that determine control of a substance:

  • Its actual or relative potential for abuse
  • Scientific evidence of its pharmacological effect, if known
  • The state of current scientific knowledge regarding the drug or other substance
  • Its history and current pattern of abuse
  • The scope, duration, and significance of abuse
  • What, if any, risk there is to the public health
  • Its psychic or physiological dependence liability
  • Whether the substance is an immediate precursor of a substance already controlled

If the DEA were to reschedule marijuana, it will “open the door” to additional veterinary research in this area, according to Dr. Joseph Wakshlag, a professor in the Department of Clinical Sciences at Cornell University College of Veterinary Medicine.

“It will be good for veterinary research moving forward to better understand how cannabinoids can be utilized in veterinary medicine as we already have a basic understanding across species regarding pharmacokinetics of cannabinoids, and which species show good oral bioavailability,” Dr. Wakshlag said.  

“Although there is some promising pharmacodynamic research out there already for a number of ailments, it will open the door to tetrahydrocannabinol and a plethora of other cannabinoids that have medicinal potential to help all companion animal species,” he added.

A version of this story appears in the April 2024 print issue of JAVMA

The AVMA, through its Division of Animal and Public Health and with input from the Council on Biologic and Therapeutic Agents and its Clinical Practitioners Advisory Committee, has developed educational resources on the topic for veterinarians and their clients. Read the report "Cannabis: What Veterinarians Need to Know."

More information on cannabis in veterinary medicine is available on the Association’s website.