MBDB is not listed as scheduled in the United States but is very likely controlled as a positional isomer of MDE, making it a Schedule I drug. In 2006 & 2007, DEA published a clarification of what they consider "positional isomers", a term not mentioned in the original CSA: Definition of "Positional Isomer" as It Pertains to the Control of Schedule I Controlled Substances, making it clear that they would consider MBDB a positional isomer of a schedule I substance (MDE).

Previously, we wrote that the legality of MBDB was complicated, but the DEA has now closed the question of whether "isomer" for Schedule I drugs would apply to MBDB being a positional isomer of MDE. In this case, a methyl (CH3) is moved from one sub-chain to another: MDE and MBDB compared.

It is also possible that MDDB could be considered an analog (of MDE), in which case, sales for human consumption or possession with the intent to ingest could be prosecuted under the Federal Analogue Act though we are unaware of any such existing cases (May 8 2024).

DEA & FDA Documents describing MBDB as a "positional isomer" of MDE:

• FDA's Comments to the WHO, 2000
• DEA's Response to the WHO, 1998
• DEA : Microgram vol 29, number 11, Nov 1996:
  

  "MBDB is a positional isomer of 3,4-methylenedioxy-N-ethylamphetamine, also known as MDE. MDE is an hallucinogenic drug in Schedule I of the CSA. In accordance with 21 CFR 1308.11 (d), optical, positional, and geometric isomers of Schedule I hallucinogenic drugs are also controlled in Schedule I; therefore, MBDB, which is positional isomer of MDE is also in Schedule I of the CSA. A notice confirming the Schedule I control status of MBDB under the CDA will be published in the Federal Register in the near future."