XLR-11, also known as 5″-fluoro-UR-144 or 5F-UR-144, operates as a potent agonist for cannabinoid receptors CB1 and CB2, displaying EC50 values of 98 nM and 83 nM, respectively. This compound belongs to the 3-(tetramethylcyclopropylmethanoyl)indole derivative family, sharing structural relations with compounds like UR-144, A-796,260, and A-834,735. However, it is noteworthy that XLR-11 needs to be explicitly documented in the patent or scientific literature alongside these analogous compounds despite falling within the scope of patent WO 2006/069196.
Furthermore, research has indicated that XLR-11 induces rapid and short-lived hypothermic effects in rats when administered at doses of 3 mg/kg and 10 mg/kg, suggesting its potency is comparable to that of APICA and STS-135.

IUPAC name
CAS Number1364933-54-9 
PubChem CID57501498
CompTox Dashboard (EPA)DTXSID00159825
Chemical and physical data
Molar mass329.459 g·mol−1


  • A forensic standard for XLR-11 is readily available, and a representative mass spectrum has been made accessible through Forendex.

Recreational Use

  • XLR-11 emerged in 2012 as a newfound ingredient in synthetic cannabis smoking blends. It appears to have been specifically developed for recreational use in the grey market, showcasing its role in the world of designer drugs.

Legal Status

  • New Zealand took the step to ban XLR-11 by including it in the temporary class drug schedule, effective from July 13, 2012.
  • The U.S. Drug Enforcement Administration (DEA) classified synthetic cannabinoids UR-144, XLR-11, and AKB48 as Schedule I illegal drugs under the Controlled Substances Act (CSA) for the next two years, starting from May 16, 2013.
  • XLR-11 was prohibited in Florida as of December 11, 2012.
  • Arizona implemented a ban on XLR-11 on April 3, 2013.
  • As of October 2015, XLR-11 is classified as a controlled substance in China.
  • The Czech Republic has also banned XLR-11.

Side Effects

  • XLR-11 has been associated with cases of hospitalizations due to its use, underlining potential health risks.


  • Some users have reported acute kidney injury linked to XLR-11 use, a concern shared with AM-2201.


1. What is XLR-11?

  • XLR-11 is a synthetic cannabinoid that has been used in synthetic cannabis smoking blends. It is known for its psychoactive effects, similar to natural cannabinoids found in marijuana.

2. How is XLR-11 detected in drug tests?

  • XLR-11 can be identified in drug tests using forensic standards and mass spectrometry. These methods are commonly employed to detect the presence of the compound in biological samples.

3. What is the legal status of XLR-11?

  • The legal status of XLR-11 varies by country and region. It has been banned or classified as a controlled substance in several places, including the United States, New Zealand, and China. The legal status should be checked according to local laws and regulations.

4. What are the side effects of XLR-11 use?

  • XLR-11 has been linked to cases of hospitalizations, indicating potential health risks associated with its use. The compound’s effects can be unpredictable and may lead to adverse reactions in some individuals.

5. Is XLR-11 safe for recreational use?

  • XLR-11 is not considered safe for recreational use. It is a synthetic compound with unregulated production, which can result in varying potencies and unknown additives. Its use carries risks, including health-related complications.

6. How does XLR-11 compare to natural cannabinoids like THC?

  • XLR-11 is designed to mimic the effects of natural cannabinoids like THC (found in marijuana). However, its effects can be more potent and unpredictable, making it potentially more dangerous.

7. Is there a medical use for XLR-11?

  • XLR-11 is not approved for medical use. Its development and service have been primarily recreational and associated with the grey-market production of synthetic drugs.

8. Where can I find more information about XLR-11?

  • To learn more about XLR-11, its effects, legal status, and potential health risks, consult reputable sources, including government health agencies, substance abuse resources, and scientific literature. It is essential to rely on accurate and up-to-date information regarding this synthetic cannabinoid.


  1. In July 2023, Anvisa issued “RDC Nº 804,” a resolution in Brazilian Portuguese listing substances under special control, including narcotics, psychotropics, and precursors, signifying a significant regulatory update in Brazil.
  2. The study conducted by Banister SD and colleagues in August 2015, titled “Effects of bioisosteric fluorine in synthetic cannabinoid designer drugs,” provides valuable insights into the impact of fluorine substitutions in synthetic cannabinoids, such as XLR-11.
  3. WO application 2006069196, filed by Pace JM, Tietje K, Dart MJ, and Meyer MD, pertains to the development of “3-Cycloalkylcarbonyl indoles as cannabinoid receptor ligands,” representing a pivotal step in the invention of compounds like XLR-11.
  4. Research led by Frost JM, Dart MJ, Tietje KR, and others, published in January 2010, examined the effects of N1 substituted indole side chain variations on CB(2) cannabinoid receptor activity, contributing to a deeper understanding of compounds like XLR-11.
  5. XLR-11 is documented in the “Structural, chemical, and analytical data on controlled substances” by the Southern Association of Forensic Scientists (SAFS), providing valuable information about this synthetic cannabinoid.
  6. Wilkinson SM’s study in 2015, titled “Bioisosteric Fluorine in the Clandestine Design of Synthetic Cannabinoids,” sheds light on the role of fluorine in the design of synthetic cannabinoids, including those like XLR-11.
  7. New Zealand Gazette’s “Temporary Class Drug Notice” from July 5, 2012, classifies XLR-11 as a temporary class drug, reflecting regulatory actions taken in New Zealand.
  8. The U.S. Drug Enforcement Administration (DEA) classified XLR-11 as a Schedule I illegal drug under the Controlled Substances Act (CSA) on June 16, 2013.
  9. Florida prohibited XLR-11 on December 11, 2012, as indicated in the press release by the State of Florida.
  10. Arizona implemented a ban on XLR-11 on April 3, 2013, according to the press release from the Office of the Governor, State of Arizona.
  11. As of October 2015, XLR-11 is classified as a controlled substance in China, as indicated by the China Food and Drug Administration.
  12. XLR-11 is also banned in the Czech Republic, with specific measures taken to regulate its use.
  13. XLR-11 has been linked to cases of hospitalizations due to its use, underscoring potential health risks associated with the compound.
  14. XLR-11 has been associated with cases of acute kidney injury in some users, alongside other synthetic cannabinoids.
  15. The U.S. Centers for Disease Control and Prevention (CDC) reported on “Acute Kidney Injury Associated with Synthetic Cannabinoid Use – Multiple States, 2012,” highlighting the public health concerns related to synthetic cannabinoids like XLR-11.

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