Schedules of Controlled Substances: Placement of Diphenidine in Schedule I

What it does

With the issuance of this final rule, the Drug Enforcement Administration places the substance diphenidine (1-(1,2- diphenylethyl)piperidine), including its salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible, in schedule I of the Controlled Substances Act. This action is being taken, in part, to enable the United States to meet its obligations under the 1971 Convention on Psychotropic Substances. This action imposes the regulatory controls and administrative, civil, and criminal sanctions applicable to schedule I controlled substances on persons who handle (manufacture, distribute, reverse distribute, import, export, engage in research, conduct instructional activities or chemical analysis with, or possess) or propose to handle diphenidine.

The Drug Enforcement Administration's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 21 of the Code of Federal Regulations:

21 CFR 1308

Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).

Compared with

The Drug Enforcement Administration has published 26 final rules in 2026 so far, compared with 17 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

What happens next and when

Effective date: October 21, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket DEA-2026-0892 on Regulations.gov
• Title 21 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register