Yes, marijuana is classified as a drug under both federal law and scientific definitions. The U.S. government currently places it in Schedule I of the Controlled Substances Act, the most restrictive category, alongside heroin and LSD. From a pharmacological standpoint, cannabis meets every criterion for a psychoactive drug: it contains chemicals that bind to specific receptors in the brain and alter mood, perception, and cognition.
How Cannabis Is Classified Under Federal Law
The Drug Enforcement Administration (DEA) organizes controlled substances into five schedules based on two factors: whether the drug has an accepted medical use and how likely it is to be abused or cause dependence. Schedule I is reserved for substances the federal government considers to have no currently accepted medical use and a high potential for abuse. Marijuana has been in this category since the Controlled Substances Act was enacted in 1970.
This classification puts cannabis in the same legal tier as heroin, ecstasy, and peyote, and in a more restrictive category than fentanyl, cocaine, and methamphetamine (all Schedule II). That ranking has long been controversial, since dozens of states have legalized cannabis for medical or recreational use while the federal government maintains its Schedule I status.
That may be changing. In August 2023, the Department of Health and Human Services recommended moving marijuana to Schedule III, citing evidence that it has accepted medical uses for treating pain, nausea and vomiting (particularly from chemotherapy), and anorexia related to medical conditions. The Department of Justice followed with a formal proposal to reclassify it. HHS found that marijuana’s abuse potential is lower than Schedule I and II drugs, and that abuse may lead to moderate or low physical dependence but high psychological dependence. If finalized, Schedule III status would acknowledge cannabis as a drug with legitimate medical applications while still regulating it as a controlled substance.
Why Cannabis Qualifies as a Drug Scientifically
In pharmacology, a drug is any substance that changes how the body functions when consumed. Cannabis easily meets that definition. The plant produces more than 100 naturally occurring chemicals called cannabinoids, and the two most abundant are THC and CBD. THC is the compound responsible for the “high.” It works by activating a specific receptor in the brain called CB1, which is concentrated in areas that control memory, coordination, pleasure, and thinking. When THC reaches those receptors, it triggers the euphoric and psychoactive effects users experience.
CBD, the other major cannabinoid, does not activate CB1 receptors and doesn’t produce a high. It interacts with the body differently, which is why CBD products are often marketed separately from marijuana.
Your body actually produces its own cannabinoid-like chemicals, called endocannabinoids, that naturally activate the same CB1 and CB2 receptors. These internal chemicals help regulate pain, mood, appetite, and immune function. THC essentially mimics those natural compounds but in a much stronger, less controlled way, which is why it produces noticeable psychoactive effects.
FDA-Approved Drugs Derived From Cannabis
The FDA has never approved whole-plant cannabis as a safe and effective drug for any condition. However, it has approved individual cannabinoid-based medications. Epidiolex, a purified form of CBD, is approved for certain severe seizure disorders. Two other approved drugs contain synthetic versions of THC and are used to treat nausea from chemotherapy and weight loss in AIDS patients. These medications went through the standard clinical trial process and are available by prescription, which is a different regulatory path than state-level medical marijuana programs.
The existence of these approved medications is part of the argument for rescheduling. Over six million patients are registered in state medical marijuana programs, and more than 30,000 healthcare providers are authorized to recommend cannabis. A 2017 report from the National Academies of Sciences found substantial evidence supporting cannabis for pain treatment, and lower-quality evidence supporting its use for nausea, vomiting, and appetite loss.
Hemp vs. Marijuana: The Legal Line
Hemp and marijuana come from the same plant species, but federal law draws a sharp line between them based on THC content. The 2018 Farm Bill removed hemp from the controlled substances list, defining it as cannabis containing less than 0.3% delta-9 THC by dry weight. Anything above that threshold is legally marijuana and remains a controlled substance.
That distinction created what became known as the “farm bill loophole.” Because only delta-9 THC was specified, manufacturers began selling products containing other psychoactive THC variants (like delta-8) derived from hemp. Congress closed this gap in late 2025 by changing the definition to include total THC concentration rather than just delta-9. Under the updated law, which takes effect in November 2026, hemp-derived cannabinoid products cannot contain more than 0.4 milligrams of THC per container.
Cannabis Use Disorder
The medical community also classifies problematic cannabis use as a diagnosable condition. The DSM-5, the standard reference for psychiatric diagnoses, defines cannabis use disorder based on 11 criteria. These include developing tolerance (needing more to get the same effect), experiencing withdrawal symptoms, unsuccessful attempts to cut back, spending excessive time obtaining or using cannabis, and continuing use despite it causing problems at work, school, or in relationships.
Meeting two or more of these criteria qualifies as a diagnosis. Two to three criteria is considered mild, four to five is moderate, and six or more is severe. The DSM-5 was the first edition to formally include cannabis withdrawal and craving as diagnostic criteria, reflecting growing evidence that regular, heavy use can produce real physical dependence, not just a psychological habit.
International Classification
Cannabis is regulated internationally under the Single Convention on Narcotic Drugs, a 1961 treaty that remains the foundation of global drug control law. The treaty restricts cannabis production, trade, and use exclusively to medical and scientific purposes. Signatory countries are expected to prohibit non-medical cultivation and report any authorized growing to international bodies. While individual nations have moved toward legalization or decriminalization in recent years, the treaty framework still treats cannabis as a controlled narcotic substance on the world stage.