Methyprylon

Methyprylon is listed by exact name as a Schedule III depressant under the Controlled Substances Act, 21 U.S.C. § 812(c), as implemented at 21 C.F.R. § 1308.13(c)(10). The Schedule III provision covers any material, compound, mixture, or preparation containing any quantity of methyprylon unless specifically excepted or listed in another schedule. Federal controls apply to possession, manufacture, distribution, dispensing, and possession with intent to manufacture, distribute, or dispense; simple possession is excepted when obtained under a valid prescription or order or otherwise authorized by the Controlled Substances Act.

Since 14 May 1997, methyprylon, expressly named as 3,3-diethyl-5-methyl-2,4-piperidinedione, has been listed in Schedule IV, item 17 of the Controlled Drugs and Substances Act. The Act prohibits trafficking, possession for trafficking, unauthorized import or export, possession for export, unauthorized production, and obtaining it from a practitioner without the disclosure required by subsection 4(2); the ordinary-possession prohibition in subsection 4(1) applies only to Schedules I, II, and III, not Schedule IV. The current Benzodiazepines and Other Targeted Substances Regulations also list methyprylon as a Class 1 targeted substance and permit pharmacists to supply targeted substances to individuals by prescription. The replacement Controlled Substances Regulations are not yet in force; they take effect on 1 October 2026 and retain methyprylon in Schedule 3, Part 2, item 10.