SUPPLEMENTARY INFORMATION:

In this final rule, the Drug Enforcement Administration (DEA) permanently places the following four substances in schedule I of the Controlled Substances Act (CSA), including their salts, isomers, and salts of isomers, whenever the existence of such salts, isomers, and salts of isomers is possible within the specific chemical designation:

• methyl 2-[[1-(4-fluorobutyl)indole-3-carbonyl]amino]-3,3-dimethyl-butanoate (other names: 4F-MDMB-BUTICA; 4F-MDMB-BICA),
• N -(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(pent-4-en-1-yl)-1 H -indazole-3-carboxamide (other name: ADB-4en-PINACA),
• ethyl 2-[[1-(5-fluoropentyl)indole-3-carbonyl]amino]-3,3-dimethyl-butanoate (other names: 5F-EDMB-PICA; 5F-EDMB-2201), and,
• methyl 2-(1-(4-fluorobenzyl)-1H -indole-3-carboxamido)-3-methyl butanoate (other name: MMB-FUBICA).

Legal Authority

Pursuant to 21 U.S.C. 811(a)(1) and (2), the Attorney General (as delegated to the Administrator of the DEA pursuant to 28 CFR 0.100) may, by rule, and upon the recommendation of the Secretary of Health and Human Services, add to such a schedule or transfer between such schedules any drug or other substance, if she finds that such drug or other substance has a potential for abuse, and makes with respect to such drug or other substance the findings prescribed by 21 U.S.C. ( printed page 23360) 812(b) for the schedule in which such drug or other substance is to be placed.

Background

The neurochemical effects of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA occur primarily through cannabinoid receptor systems in the brain. 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA bind to cannabinoid subtype 1 (CB1) receptors, function as full agonists, and have a binding affinity and functional activity profile that is similar to that of other schedule I cannabinoids, including Δ9-THC, JWH-018, XLR11, and AKB-48.

DEA published an order in the Federal Register on December 12, 2023, temporarily placing 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA in schedule I of the CSA based upon a finding that these substances pose an imminent hazard to the public safety under 21 U.S.C. 811(h)(1).^[1] That temporary order was effective upon the date of publication. On December 10, 2025, the DEA Administrator signed a temporary scheduling order to extend the temporary schedule I status of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA for one year, or until the permanent scheduling action for these substances are completed, whichever occurs first.^[2]

DEA and HHS Eight-Factor Analyses

In a letter dated December 3, 2025, in accordance with 21 U.S.C. 811(b), and in response to DEA's April 15, 2025 request, the Department of Health and Human Services (HHS) provided to DEA a scientific and medical evaluation and scheduling recommendation for 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA. DEA reviewed the scientific and medical evaluation and scheduling recommendation for schedule I placement provided by HHS, and all other relevant data, pursuant to 21 U.S.C. 811(b) and (c), and conducted its own analysis under the eight factors stipulated in 21 U.S.C. 811(c). DEA found, under 21 U.S.C. 811(b)(1), that 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA warrant control in schedule I. Both DEA and HHS's Eight-Factor Analyses are available in their entirety under the tab Supporting Documents of the public docket for this action at https://www.regulations.gov under docket number DEA-1604.

Notice of Proposed Rulemaking To Schedule 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA

On December 10, 2025, the DEA Administrator signed a notice of proposed rulemaking (NPRM) to permanently control 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA in schedule I.^[3] Specifically, DEA proposed to add 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA to the list of hallucinogenic substances under 21 CFR 1308.11(d). The NPRM provided an opportunity for interested persons to file a request for hearing in accordance with DEA regulations on or before January 15, 2026. DEA did not receive any requests for a hearing. The NPRM also provided an opportunity for interested persons to submit comments on or before January 15, 2026.

Comments Received

DEA received one comment in response to the NPRM that was not related to the rulemaking for the placement of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA into schedule I of the CSA.

Comment that was not related to this rulemaking: DEA received one comment that was neither explicitly for nor against the proposed rule. This comment discussed marijuana and was not related to the current scheduling action.

DEA Response: This comment was outside the scope of the current scheduling action; therefore, it was not considered.

Scheduling Conclusion

After consideration of the public comment, scientific and medical evaluation and accompanying scheduling recommendation from HHS, and after its own eight-factor evaluation, DEA finds that these facts and all relevant data constitute substantial evidence of potential for abuse of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA. As such, DEA is permanently scheduling 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA as controlled substances under schedule I of the CSA.

Determination of Appropriate Schedule

The CSA establishes five schedules of controlled substances known as schedules I, II, II, IV, and V. The CSA also specifies the findings requires to place a drug or other substance in any particular schedule, 21 U.S.C. 812(b). After consideration of the analysis and recommendation of the then Assistant Secretary for Health of HHS and review of all other available data, the Administrator of DEA, pursuant to 21 U.S.C. 812(b)(1), finds that:

(1) 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA have a high potential for abuse that is comparable to other scheduled synthetic cannabinoids, such as JWH-018, XLR11, and AKB-48. In vitro studies demonstrate that 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA bind to CB1 receptors and function as full agonists. In drug discrimination studies conducted in animals to evaluate its discriminative stimulus effects, 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA were shown to fully substitute for the discriminative stimulus effects produced by delta 9-THC. The ingestion of 4F-MDMB-BUTICA, ADB-4en-PINACA, or 5F-EDMB-PICA has been documented to result in serious adverse effects, including poisonings and deaths. Based upon results from in vitro and in vivo studies, and its similarity to other schedule I synthetic cannabinoids, MMB-FUBICA in particular would be expected to cause similar serious adverse effects following its ingestion.

(2) 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA have no currently accepted medical use in treatment in the United States. In HHS's 2025 recommendation to control 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA, it was noted there are no approved New Drug Applications and no known therapeutic applications for these substances in the United States. DEA is not aware of any other evidence suggesting that 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA have a currently accepted medical use in treatment in the United States.^[4]

( printed page 23361)

(3) There is a lack of accepted safety for use of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA under medical supervision. Because 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA have no approved medical use and have not been investigated as new drugs, their safety for use under medical supervision has not been determined.

Based on these findings, the DEA Administrator concludes that 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA, as well as their salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible, warrant control in schedule I of the CSA.

Requirements for Handling 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA

4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA are subject to the CSA's schedule I regulatory controls and administrative, civil, and criminal sanctions applicable to the manufacture, distribution, reverse distribution, import, export, engagement in research, conduct instructional activities or chemical analysis with, and possession of schedule I controlled substances, including the following:

1. Registration. Any person who handles (manufactures, distributes, reverse distributes, imports, exports, engages in research, or conducts instructional activities or chemical analysis with, or possesses), or who desires to handle, 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA must register with DEA to conduct such activities pursuant to 21 U.S.C. 822, 823, 957, and 958, and in accordance with 21 CFR parts 1301 and 1312.

Any person who currently handles 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA and is not registered with DEA to conduct research with a schedule I controlled substance must submit an application for registration and may not continue to handle 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA as of May 1, 2026, unless DEA has approved that application for registration pursuant to 21 U.S.C. 822, 823, 957, and 958, and in accordance with 21 CFR parts 1301 and 1312.

Notwithstanding the foregoing, pursuant to 21 U.S.C. 822(h), if, on May 1, 2026, a person is conducting research on 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA and is already registered to conduct research with another controlled substance in schedule I, the person may continue to conduct research on 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA if they submit a completed application for registration or modification of existing registration, as applicable, to conduct research with 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA not later than 90 calendar days after May 1, 2026. The person may continue to conduct such research until the person withdraws the application or the Administrator serves on the person an order to show cause proposing denial of the application pursuant to 21 U.S.C. 824(c) and in accordance with 21 CFR 1301.37. If the Administrator serves an order to show cause proposing denial of the application or modification, the person may not continue to conduct research with 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA and may not receive or otherwise obtain additional 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA. If an order to show cause is served and the person requests a hearing in accordance with 21 CFR 1301.37(d), the hearing shall be held in accordance with 21 CFR 1301.41-1301.46 on an expedited basis and not later than 45 calendar days after the request is made, except that the hearing may be held at a later time if so requested by the person. If the person sends a copy of the application to a manufacturer or distributor of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA, receipt of the copy by the manufacturer or distributor constitutes sufficient evidence that the person is authorized to receive 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA pursuant to 21 U.S.C. 822(h)(4). Continuation of research under 21 U.S.C. 822(h) does not authorize any other handling ( e.g., distribution) of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA.

Retail sales of schedule I controlled substances to the general public are not allowed under the CSA. Possession of any quantity in a manner not authorized by the CSA is unlawful and those in possession of any quantity may be subject to prosecution pursuant to the CSA.

2. Disposal of stocks. Any person unwilling or unable to obtain a schedule I registration must surrender or transfer all quantities of currently held 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA to a person registered with DEA before the effective date of the final scheduling action in accordance with all applicable Federal, State, local, and Tribal laws. 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA must be disposed of in accordance with 21 CFR part 1317, in addition to all other applicable Federal, State, local, and Tribal laws

3. Security. 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA are subject to schedule I security requirements and must be handled and stored pursuant to 21 U.S.C. 823, and in accordance with 21 CFR 1301.71-1301.76. Non-practitioners handling 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA must comply with the employee screening requirements of 21 CFR 1301.90 through 1301.93.

4. Labeling and Packaging. All labels, labeling, and packaging for commercial containers of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA must comply with 21 U.S.C. 825 and be in accordance with 21 CFR part 1302.

5. Quota. Generally, only registered manufacturers are permitted to manufacture 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA in accordance with a quota assigned pursuant to 21 U.S.C. 826, and in accordance with 21 CFR part 1303. ( printed page 23362)

6. Inventory. Every DEA registrant who possesses any quantity of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA must take an inventory of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA on hand, pursuant to 21 U.S.C. 827 and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (d).

Any person who registers with DEA must take an initial inventory of all stocks of controlled substances (including 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA) on hand on the date the registrant first engages in the handling of controlled substances, pursuant to 21 U.S.C. 827 and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (b).

After the initial inventory, every DEA registrant must take an inventory of all controlled substances (including 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA) on hand every two years, pursuant to 21 U.S.C. 827 and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11.

7. Records and Reports. Every DEA registrant must maintain records and submit reports for 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA, or products containing 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA, pursuant to 21 U.S.C. 827 and in accordance with 21 CFR 1301.74(b) and (c), 1301.76(b), and parts 1304, 1312 and 1317. Manufacturers and distributors must submit reports regarding 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA to the Automation of Reports and Consolidated Order System pursuant to 21 U.S.C. 827 and in accordance with 21 CFR parts 1304 and 1312.

8. Order Forms. Every DEA registrant who distributes 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA must comply with the order form requirements, pursuant to 21 U.S.C. 828 and 21 CFR part 1305.

9. Importation and Exportation. All importation and exportation of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA must comply with 21 U.S.C. 952, 953, 957, and 958, and in accordance with 21 CFR parts 1304 and 1312.

10. Liability. Any activity involving 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA not authorized by, or in violation of, the CSA or its implementing regulations, is unlawful, and may subject the person to administrative, civil, and/or criminal sanctions.

Regulatory Analyses

Executive Orders 12866, 13563, 14192, and 14294

In accordance with 21 U.S.C. 811(a), this final scheduling action is subject to formal rulemaking procedures performed “on the record after opportunity for a hearing,” which are conducted pursuant to the provisions of 5 U.S.C. 556 and 557. The CSA sets forth the procedures and criteria for scheduling a drug or other substance. Such actions are exempt from review by the Office of Management and Budget (OMB) pursuant to section 3(d)(1) of Executive Order (E.O.) 12866 and the principles reaffirmed in E.O. 13563. DEA scheduling actions are not subject to either E.O. 14192, Unleashing Prosperity Through Deregulation, or E.O. 14294, Overcriminalization in Federal Regulations.

Executive Order 12988, Civil Justice Reform

This regulation meets the applicable standards set forth in sections 3(a) and 3(b)(2) of E.O. 12988 to eliminate drafting errors and ambiguity, minimize litigation, provide a clear legal standard for affected conduct, and promote simplification and burden reduction.

Executive Order 13132, Federalism

This rulemaking does not have federalism implications warranting the application of E.O. 13132. The rule does not have substantial direct effects on the states, on the relationship between the National Government and the States, or on the distribution of power and responsibilities among the various levels of government.

Executive Order 13175, Consultation and Coordination With Indian Tribal Governments

This rule does not have tribal implications warranting the application of E.O. 13175. It does not have substantial direct effects on one or more Indian tribes, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes.

Paperwork Reduction Act of 1995

This action does not impose a new collection or modify an existing collection of information under the Paperwork Reduction Act of 1995.^[5] Also, this rule does not impose new or modify existing recordkeeping or reporting requirements on state or local governments, individuals, businesses, or organizations. However, this rule would require compliance with the following existing OMB collections: 1117-0003, 1117-0004, 1117-0006, 1117-0008, 1117-0009, 1117-0010, 1117-0012, 1117-0014, 1117-0021, 1117-0023, 1117-0029, and 1117-0056. An agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number.

Regulatory Flexibility Act

The Administrator of DEA, in accordance with the Regulatory Flexibility Act, 5 U.S.C. 601-612, has reviewed this final rule, and by approving it, certifies that it will not have a significant economic impact on a substantial number of small entities.

DEA is placing methyl 2-[[1-(4-fluorobutyl)indole-3-carbonyl]amino]-3,3-dimethyl-butanoate (other names: 4F-MDMB-BUTICA; 4F-MDMB-BICA), N -(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(pent-4-en-1-yl)-1 H -indazole-3-carboxamide (other name: ADB-4en-PINACA), ethyl 2-[[1-(5-fluoropentyl)indole-3-carbonyl]amino]-3,3-dimethyl-butanoate (other names: 5F-EDMB-PICA; 5F-EDMB-2201), and methyl 2-(1-(4-fluorobenzyl)-1 H -indole-3-carboxamido)-3-methyl butanoate (other name: MMB-FUBICA), including their salts, isomers, and salts of isomers, in schedule I of the CSA. 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 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA.

Based on the review of HHS's scientific and medical evaluation and all other relevant data, DEA determined that 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA have a high potential for abuse, have no currently accepted medical use in treatment in the United States, and lack accepted safety for use under medical supervision. There appear to be no legitimate sources for 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA as marketed drugs in the United States, but DEA notes that this substance is available for purchase from legitimate suppliers for scientific research. There is no evidence of significant diversion of 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, or MMB-FUBICA from legitimate suppliers. Therefore, this final rule will ( printed page 23363) not have a significant economic impact on a substantial number of small entities.

Unfunded Mandates Reform Act of 1995

In accordance with the Unfunded Mandates Reform Act (UMRA) of 1995, 2 U.S.C. 1532, DEA has determined that this action would not result in any Federal mandate that may result “in the expenditure by State, local, and Tribal governments, in the aggregate, or by the private sector, of $100,000,000 or more (adjusted annually for inflation) in any 1 year. . . .” Therefore, neither a Small Government Agency Plan nor any other action is required under UMRA of 1995.

Congressional Review Act

This rule is not a major rule as defined by the Congressional Review Act (CRA), 5 U.S.C. 804. However, pursuant to the CRA, DEA is submitting a copy of this rule to both Houses of Congress and to the Comptroller General.

Determination To Make Rule Effective Immediately

The Administrative Procedure Act (APA) generally requires that rules enacted in accordance with the procedures of 5 U.S.C. 553 to be effective not less than 30 days after publication of the proposed rule.^[6] However, the APA provides three exceptions for when an agency may make a rule effective sooner than 30 days after publication, including if the agency finds for good cause why the rule should be effective sooner and publishes those reasons with the rule.^[7]

DEA finds that there is good cause for this scheduling action to be immediately effective upon publication because a delay in the effective date is unnecessary and contrary to the public interest. First, it is unnecessary because 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA are currently listed in schedule I of the CSA under 21 U.S.C. 811(h).^[8] Second, as discussed in the temporary scheduling order and NPRM, 4F-MDMB-BUTICA, ADB-4en-PINACA, 5F-EDMB-PICA, and MMB-FUBICA pose imminent hazards to public safety. Therefore, DEA believes it is unnecessary and contrary to the public interest to delay the effectiveness of this final rule by 30 days.^[9]

For the reasons set out above, DEA amends 21 CFR part 1308 as follows:

Signing Authority

This document of the Drug Enforcement Administration was signed on March 23, 2026, by DEA Administrator Terrance C. Cole. That document with the original signature and date is maintained by DEA. For administrative purposes only, and in compliance with requirements of the Office of the Federal Register, the undersigned DEA Federal Register Liaison Officer has been authorized to sign and submit the document in electronic format for publication, as an official document of DEA. This administrative process in no way alters the legal effect of this document upon publication in the Federal Register .

91 FR 23359