Drugs currently classified as Schedule I have what characteristic in the United States?

Drugs classified as Schedule I in the United States are characterized by having no accepted medical use. This classification is part of the Controlled Substances Act and indicates that these substances are considered to be the most dangerous due to their high potential for abuse, lack of accepted safety for use under medical supervision, and absence of medical applications recognized by the FDA.

While Schedule I drugs indeed have a high potential for abuse, it is their lack of any accepted medical use that primarily distinguishes this category from others. In contrast, other schedules may include substances that have accepted medical applications, albeit with restrictions based on their abuse potential. Thus, the defining characteristic that places a drug in Schedule I is specifically its lack of accepted medical use in treatment in the United States.