"Schedule I drugs, substances, or chemicals are defined as drugs with no currently accepted medical use and a high potential for abuse. Some examples of Schedul

"Schedule I drugs, substances, or chemicals are defined as drugs with no currently accepted medical use and a high potential for abuse. Some examples of Schedule I drugs are: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote." https://www.dea.gov/drug-information/drug-scheduling https://www.dea.gov/drug-information/drug-scheduling The key phrase is "currently accepted medical use". That is an arbitrary definition that is set by the regulator. A drug must have a medical use that is accepted by the DEA who defers to the FDA for such definitions.