JWH 398 is a synthetic cannabinoid (CB) that activates both central CB1 and peripheral CB2 receptors (Ki = 2.3 and 2.8 nM, respectively). It has been reported to be an adulterant of herbal products. JWH 398 N-(4-hydroxypentyl) metabolite is an expected phase I metabolite of JWH 398 , detectable in serum and urine. While similar hydroxylated phase I metabolites of synthetic CBs retain activity, the physiological properties of this compound have yet to be determined. This product is intended for research and forensic applications.