XLR-11 (drug)
XLR-11 (5"-fluoro-UR-144) is a drug that acts as a potent agonist for the cannabinoid receptors CB1 and CB2 with a Ki of 24.2nM and a EC50 of 359nM at CB1. 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.
Detection
A forensic standard for this compound is available, and a representative mass spectrum has been posted on Forendex. An ELISA immunoassay technique for detecting XLR-11 and UR-144 in blood and urine as part of general drug screens has been developed by Randox Laboratories and Tulip Biolabs, Inc.
Recreational use
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. It was banned in New Zealand by being added to the temporary class drug schedule, effective from 13 July 2012. It has also been banned in Florida as of 11 December 2012. Arizona banned XLR-11 on April 3, 2013.
Toxicity
XLR-11 has been linked to acute kidney injury in some users, along with AM-2201.