XLR11 N-(4-hydroxypentyl) metabolite-d5 (CRM) is intended for use as an internal standard for the quantification of XLR11 N-(4-hydroxypentyl) metabolite (Item No. 17727) by GC- or LC-mass spectrometry. XLR11 (Item No. 11565) is a synthetic cannabinoid (CB) featuring a tetramethylcyclopropyl group, which reportedly confers selectivity for the peripheral CB2 receptor over the central CB1 receptor.1 XLR11 also has an N-(5-fluoropentyl) chain, which increases binding to both CB receptors.2 XLR11 N-(4-hydroxypentyl) metabolite is an expected phase 1 metabolite of XLR11, based on the known metabolism of similar compounds.3,4 The physiological properties of this compound have not been evaluated. This product is intended for forensic and research applications.WARNING This product is not for human or veterinary use.