The Drug Enforcement Administration issued a temporary scheduling order placing mitragynine pseudoindoxyl, MGM-15, and MGM-16 in Schedule I of the Controlled Substances Act on August 24, 2026. The agency stated that placing these substances in Schedule I is necessary to avoid an imminent hazard to public safety.

The temporary order is effective upon publication in the Federal Register and remains in effect until August 26, 2028. It imposes regulatory controls and administrative, civil, and criminal sanctions applicable to Schedule I controlled substances on persons who handle or propose to handle these substances. The temporary scheduling order includes the isomers, esters, ethers, salts, and salts of isomers, esters, and ethers of mitragynine pseudoindoxyl, MGM-15, and MGM-16.

Mitragynine pseudoindoxyl is chemically identified as Methyl (E)-2-((1′S,6′S,7′S)-6′-ethyl-4-methoxy-3-oxo-3′,5′,6′,7′,8′,8a′-hexahydro2′H-spiro[indoline-2,1′-indolizine]-7′-yl)-3-methoxyacrylate. MGM-15 is chemically identified as Methyl (E)-2-((2S,3S,7aS,12aR,12bS)-3-ethyl-7a-hydroxy-8-methoxy1,2,3,4,6,7,7a,12,12a,12b-decahydroindolo[2,3-a]quinolizin-2-yl)-3methoxyacrylate and is also known as dihydro-7-hydroxymitragynine. MGM-16 is chemically identified as Methyl (E)-2-((2S,3S,7aS,12aR,12bS)-3-ethyl-9-fluoro-7a-hydroxy-8-methoxy1,2,3,4,6,7,7a,12,12a,12b-decahydroindolo[2,3-a]quinolizin-2-yl)-3methoxyacrylate and is also known as 9-fluorodihydro-7-hydroxymitragynine or 10-fluoro-dihydro-7-hydroxymitragynine.

Why It Matters

The temporary scheduling action follows a multi-step regulatory process that began in late 2025. The DEA notified the Secretary of Health and Human Services of its intent to temporarily place these substances in Schedule I by letter dated December 15, 2025. The Assistant Secretary for Health responded on January 20, 2026, stating that the Food and Drug Administration found no investigational new drug applications or approved new drug applications for these substances. The Assistant Secretary for Health also stated that the Department of Health and Human Services had no objection to the temporary placement of these substances in Schedule I.

The notice of intent discussed findings from the DEA’s three-factor analysis dated May 2026. The DEA published a notice of intent to temporarily schedule these substances in the Federal Register on July 6, 2026.

Timeline

On December 15, 2025, the Drug Enforcement Administration notified the Secretary of Health and Human Services of its intent to temporarily place these substances in Schedule I by letter dated December 15, 2025. On January 20, 2026, the Assistant Secretary for Health stated that the Department of Health and Human Services had no objection to the temporary placement of these substances in Schedule I. Also on January 20, 2026, the Assistant Secretary for Health responded on January 20, 2026, stating that the Food and Drug Administration found no investigational new drug applications or approved new drug applications for these substances. In May 2026, the notice of intent discussed findings from the Drug Enforcement Administration’s three-factor analysis dated May 2026.

On July 6, 2026, the Drug Enforcement Administration published a notice of intent to temporarily schedule these substances in the Federal Register on July 6, 2026. Also on July 6, 2026, the temporary scheduling order was published in the Federal Register on July 6, 2026, and was set to take effect on August 5, 2026, as stated in the Federal Register notice. On August 5, 2026, the official record states that the temporary scheduling of mitragynine pseudoindoxyl (MP), MGM-15, and MGM-16 into Schedule I of the Controlled Substances Act took effect on August 5, 2026, as published in the Federal Register. On August 24, 2026, the Drug Enforcement Administration issued a temporary scheduling order placing mitragynine pseudoindoxyl, MGM-15, and MGM-16 in Schedule I of the Controlled Substances Act.

What's New

The Drug Enforcement Administration is a United States federal law enforcement agency.

How Sources Differ

Regarding when the scheduling was published in the Federal Register, federalregister.gov states that the official record states that the temporary scheduling of mitragynine pseudoindoxyl (MP), MGM-15, and MGM-16 into Schedule I of the Controlled Substances Act took effect on August 5, 2026, as published in the Federal Register.