UR-144.

UR-144 belongs to the second generation of synthetic cannabinoid receptor agonists, that of the tetramethylcyclopropane indole ketones which followed the naphthoylindoles of the JWH series after their ban. Born of an Abbott Laboratories programme aiming at CB2-selective agonists, the molecule proved far less selective than announced: the preference for CB2 falls from a factor of eighty-three to a factor of six depending on assay conditions, and the affinity for CB1, of the order of 29 nM, equals or exceeds that of tetrahydrocannabinol. In animals, it substitutes completely for tetrahydrocannabinol in discrimination tests, which places it among the central agonists. The most important point for the user is heat: the tetramethylcyclopropane unit opens at combustion temperature and gives a degradation product whose agonist activity at the human CB1 receptor is about four times that of the parent molecule. What is smoked is therefore not what was sprayed, and the dose received becomes impossible to estimate. Effects reported in humans come from case series and not from controlled studies: a review of thirty-nine Polish cases from 2012 to 2015, twenty-six of which had the substance alone detected, mainly notes slowed speech and dilated pupils, with incoordination, unsteady gait and difficulty standing. Acute kidney injury has been described in association with other synthetic agonists. No controlled study has been published in humans: human data are lacking, on doses as on tolerance and dependence.

Source

An entirely synthetic molecule, absent from cannabis as from any living organism. It has no connection with hemp or with cannabidiol products. It is mostly smoked, mixed with tobacco or herbs; it can also be vaporised, inhaled or ingested (WHO report 2017). It was among the most frequently seized synthetic cannabinoids in 2015.

No known biosynthetic pathway: the molecule forms in no living organism. It comes from organic synthesis, described here only by its chemical class, the indol-3-yl tetramethylcyclopropyl ketones.

European Union

The molecule is under international control: the United Nations Commission on Narcotic Drugs placed it in Schedule II of the 1971 Convention on psychotropic substances on 14 March 2018, by 48 votes in favour, none against and no abstentions, and the Green List of the International Narcotics Control Board (35th edition, 2024) carries it under the code PU 001. This listing follows the critical review by the WHO Expert Committee on Drug Dependence in November 2017, which concluded that the data made it comparable to the synthetic cannabinoids already in that schedule, after a first review in 2014 that had recommended only surveillance; before 2018, the WHO report stated that it was under the control of no international convention. No act of the European Union names it in the annex of Framework Decision 2004/757/JHA (Directives (EU) 2017/2103, 2019/369, 2020/1687, 2021/802, 2022/1326 and 2025/2062): control rests with national legislation. According to the WHO (2017), it was already controlled in Germany in 2012, in the United Kingdom since 2013, in Denmark, Hungary, Portugal, Slovakia, Slovenia, Turkey and Russia, placed in Schedule I of US federal law (2016), and controlled in China (2016), Japan (2012) and the Republic of Korea (2014).

France

Scheduled as a narcotic in France, and named explicitly in annex III of the decree of 22 February 1990, the annex that reproduces Schedules I and II of the 1971 Convention on psychotropic substances: the consolidated list of ANSM (updated 16 February 2026) cites it under the entry “UR-144 or (1-pentylindol-3-yl)-(2,2,3,3-tetramethylcyclopropyl) methanone”, under the decree of 14 October 2019. In annex IV, the list also names a chlorinated derivative, 5Cl-UR-144, and defines the generic family of indol-3-yl methanones bearing an alkyl chain on the indole nitrogen and a cyclopropyl group on the carbon of the methanone bridge, a definition that would cover the molecule even without a named entry. It is therefore not the generic clause on tetrahydrocannabinols that applies here, the molecule not belonging to that chemical class. Production, possession, transfer, supply and use are criminally punishable.

Sources: EUR-Lex, UNODC, CND, ANSM, IUPHAR/BPS, ChEBI, EUDA. Our method.

Family

Synthetic CB receptor agonist › New psychoactive substance

Class

tetramethylcyclopropylketone

Verification

Classification, sources and binding values checked on 20 October 2026; text read against its sources and Wikipedia.

Wikipedia (English)

UR-144 (new tab)

Article paired by the molecule's structure (InChIKey), revision read on 19 October 2026. Read as a second opinion, never cited as a source.

1. 1WHO, Expert Committee on Drug Dependence, 39th meeting (Geneva, 6-10 November 2017): UR-144, Critical Review Report, item 4.11 (new tab)
2. 2Frost et al., Journal of Medicinal Chemistry, 2010: indol-3-ylcycloalkyl ketones, N1 side-chain variations and CB2 receptor activity (Abbott series) (new tab)PMID 19921781
3. 3Wiley et al., Neuropharmacology, 2013: Δ9-THC-like effects of tetramethylcyclopropyl ketone indoles (UR-144, XLR-11) (new tab)PMID 23916483
4. 4Kaizaki-Mitsumoto et al., Journal of Toxicological Sciences, 2017: pyrolysis of UR-144 increases its affinity for the human CB1 receptor and its cannabimimetic effects in the mouse (new tab)PMID 28496039
5. 5Thomas et al., Journal of Pharmacology and Experimental Therapeutics, 2017: thermolytic degradation of synthetic cannabinoids, chemical exposures and pharmacological consequences (new tab)PMID 28087785
6. 6Nielsen et al., Drug Testing and Analysis, 2016: metabolism of UR-144 and XLR-11 mediated by cytochromes P450 (new tab)PMID 26360322
7. 7Adamowicz et al., Forensic Science International, 2017: effects of UR-144 on the human body, a review of 39 cases (new tab)PMID 28283378
8. 8ANSM, consolidated list of substances classified as narcotics, updated 16 February 2026: UR-144 (annex III, order of 14 October 2019); 5Cl-UR-144 and the indol-3-yl methanone family (annex IV) (new tab)
9. 9INCB, Green List of psychotropic substances under international control, 35th edition, 2024: Schedule II, entry PU 001 (UR-144) (new tab)
10. 10CND blog, 61st session (14 March 2018), item 5: UR-144 placed in Schedule II of the 1971 Convention by 48 votes in favour, none against and no abstentions (new tab)
11. 11PubChem, Compound Summary CID 44626619, UR-144 (new tab)

SMILES

CCCCCN1C=C(C2=CC=CC=C21)C(=O)C3C(C3(C)C)(C)C

Machine-readable entry (JSON)

LLM ingestion format: a structured superset of the entry (identifiers, binding, versioned legal status). Full corpus.