XLR-11 (5"-fluoro-UR-144 or 5F-UR-144) is a drug that acts as a potent agonist for the cannabinoid receptorsCB1 and CB2 with EC50 values of 98 nM and 83 nM, respectively. It is a 3-(tetramethylcyclopropylmethanoyl)indole derivative related to compounds such as UR-144, A-796,260 and A-834,735, but it is not specifically listed in the patent or scientific literature alongside these other similar compounds, and appears to have not previously been made by Abbott Laboratories, despite falling within the claims of patent WO 2006/069196. XLR-11 was found to produce rapid, short-lived hypothermic effects in rats at doses of 3 mg/kg and 10 mg/kg, suggesting that it is of comparable potency to APICA and STS-135.
A forensic standard for this compound is available, and a representative mass spectrum has been posted on Forendex.
XLR-11 was instead first identified by laboratories in 2012 as an ingredient in synthetic cannabis smoking blends, and appears to be a novel compound invented specifically for grey-market recreational use.
XLR-11 was banned in New Zealand by being added to the temporary class drug schedule, effective from 13 July 2012.
The U.S. Drug Enforcement Administration (DEA) made the synthetic cannabinoids UR-144, XLR11, and AKB48 Schedule I, illegal drugs under the Controlled Substances Act (CSA) for the next two years as of 16 May 2013.
It has also been banned in Florida as of December 11, 2012.
^Jordan Trecki; Roy R. Gerona; Michael D. Schwartz (July 2015). "Synthetic Cannabinoid–Related Illnesses and Deaths". New England Journal of Medicine. 373 (2): 103–107. doi:10.1056/NEJMp1505328. PMID26154784.