Notes: RCS-4 is a synthetic cannabinoid which is structurally similar to JWH 018. Like JWH 018, RCS-4 has been detected in herbal products.{19508} RCS-4 N-(5-carboxypentyl) metabolite is an expected metabolite of RCS-4. Carboxylation of the N-alkyl chain of JWH 018 occurs during in vivo metabolism, resulting in a 5-carboxypentyl metabolite that is detectable in the urine.{18291}