XLR-11.

XLR-11 is the fluorinated analogue of UR-144, from which it differs only by a fluorine atom at the end of the chain carried by the indole nitrogen, a modification that has become a signature of the synthetic cannabinoid market. This fluorination raises in vitro potency at the CB1 receptor two- to five-fold on average in the series studied, without the effect translating consistently in animals. The molecule remains identified with a public health event rather than with its pharmacology: it was found in the products and specimens of several clusters of acute kidney injury in the United States in 2012, among young users, mostly men aged fifteen to twenty-seven, with intense nausea and flank or abdominal pain, creatinine peaks of up to 17.7 mg/dL and dialysis in one case out of nine in the Oregon series. No known nephrotoxin and no other cause was found, and the mechanism, direct toxicity, genetic predisposition or an unidentified contaminant, remains open. A mouse model published in 2022 also shows acute liver injury after repeated administration, with necrosis, inflammatory infiltrate, raised transaminases and an oxidative stress signature. As with its non-fluorinated analogue, compounds with a tetramethylcyclopropyl ring form degradants of distinct pharmacology on heating. No controlled study has been published in humans: human data are lacking, on effects as on doses, tolerance and dependence.

Source

An entirely synthetic molecule, absent from cannabis as from any living organism, and unrelated to hemp or cannabidiol products. It was found in smoked products sold as cannabis substitutes, dissolved in a solvent and applied to dry plant material (CDC 2013). US public-health investigations noted that these products could be bought easily in convenience stores, tobacco shops and adult bookstores (Buser 2014). The content of the products is never indicated.

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 at its 60th session (13-17 March 2017), UNODC announcing on 18 October 2017 that the decision had entered into force; the Green List of the International Narcotics Control Board (35th edition, 2024) carries it under the code PX 001. 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, France having entered it on its list of narcotics by the decree of 19 May 2015. Outside the European Union, it falls under Schedule I of US federal law: the DEA placed it on a temporary basis by an order of 16 May 2013, then permanently by a final rule of 11 May 2016 that covered together this molecule, its non-fluorinated analogue (UR-144) and AKB48.

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 “XLR-11 or 5F-UR-144 or (1-(5-fluoropentyl)-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone”, under the decrees of 19 May 2015 and 3 October 2017. It also falls under the generic family of indol-3-yl methanones defined in annex IV (a haloalkyl substituent on the indole nitrogen, a cyclopropyl group on the carbon of the methanone bridge). The generic clause on tetrahydrocannabinols does not apply, 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)

XLR-11 (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. 1Centers for Disease Control and Prevention, Acute kidney injury associated with synthetic cannabinoid use, multiple states, 2012, MMWR, 15 February 2013 (new tab)PMID 23407124
2. 2Buser et al., Clinical Toxicology, 2014: acute kidney injury associated with smoked synthetic cannabinoid use (Oregon and south-west Washington State, 2012) (new tab)PMID 25089722
3. 3Banister et al., ACS Chemical Neuroscience, 2015: effects of bioisosteric fluorine on synthetic cannabinoids (JWH-018/AM-2201, UR-144/XLR-11, PB-22/5F-PB-22, APICA/STS-135) (new tab)PMID 25921407
4. 4Nielsen et al., Drug Testing and Analysis, 2016: metabolism of UR-144 and XLR-11 mediated by cytochromes P450 (new tab)PMID 26360322
5. 5Thomas et al., Journal of Pharmacology and Experimental Therapeutics, 2017: thermolytic degradation of synthetic cannabinoids (tetramethylcyclopropyl ring compounds) (new tab)PMID 28087785
6. 6Richter et al., Toxicology Letters, 2017: metabolism of XLR-11, AB-PINACA, FUB-PB-22 and others in human liver preparations compared with primary hepatocytes and human urine (new tab)PMID 28782580
7. 7Alzu'bi et al., Toxics, 2022: acute liver injury associated with XLR-11 administration in the mouse (new tab)PMID 36355959
8. 8Kevin et al., Frontiers in Psychiatry, 2022: off-target pharmacological profiling of seven synthetic cannabinoids, including XLR-11 and PB-22 (new tab)PMID 36590635
9. 9UNODC, announcement of the entry into force, on 18 October 2017, of the placement of eight substances (including XLR-11) in Schedule II of the 1971 Convention, decided at the 60th session of the CND (13-17 March 2017) (new tab)
10. 10INCB, Green List of psychotropic substances under international control, 35th edition, 2024: Schedule II, entry PX 001 (XLR-11) (new tab)
11. 11ANSM, consolidated list of substances classified as narcotics, updated 16 February 2026: XLR-11 or 5F-UR-144 (annex III, orders of 19 May 2015 and 3 October 2017) (new tab)
12. 12DEA, final rule of 11 May 2016: placement of UR-144, XLR11 and AKB48 in Schedule I (81 FR 29142); temporary order of 16 May 2013 (78 FR 28735) (new tab)
13. 13PubChem, Compound Summary CID 57501498, XLR-11 (new tab)

SMILES

CC1(C(C1(C)C)C(=O)C2=CN(C3=CC=CC=C32)CCCCCF)C

Machine-readable entry (JSON)

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