Disappearance of Tramadol and THC-COOH in Hair After Discontinuation of Abuse: Two Different Profiles

The study analyzed hair samples from 8 tramadol and 15 cannabis users to determine how long after drug discontinuation the hair would test negative. Hair was collected 3–6 months after stopping tramadol and 6–9 months after stopping cannabis. Using LC–MS-MS, it was found that tramadol and THC-COOH remained detectable in new hair growth for several months, with negative results appearing approximately 3–4 months after tramadol cessation and 6–7 months after cannabis cessation. This delay was attributed to the contribution of dormant hair.