Cannabimimetic indoles, including certain “JWH” compounds, have been identified in herbal blends. Metabolites of two closely-related compounds, JWH 015 and JWH 018, have been identified from in vitro liver microsomal metabolism and from urine, respectively. JWH 250 is a cannabimimetic indole that is structurally- and functionally-related to JWH 015 and JWH 018. JWH 250 N-pentanoic acid metabolite is expected to be a metabolite of JWH 250 that would be detectable both in serum and in urine.