“…[18][19][20][21] A variety of drugs and endogenous substances have been accurately measured in hair, including: opiates, barbiturates, benzodiazepines, anabolic steroids, cocaine, nicotine and recently, cortisol and cortisone. [21][22][23][24][25] In clinical settings, hair drug levels have been used to assist in therapeutic drug monitoring. 24 A limited number of studies by the same principle authors have examined the incorporation and detection of cortisol in human hair.…”