text: does cough medicine (dxm) show up on a drug test? what things show up? and what are some tips for it to magically not show up...? any tips about anything not exacly legal are good yes, if the test is set up to detect opiate metabolites  and not just the opiates then selves, it will pick up dextromethorphan since it is just the dextrorotatory isomer of an opiate.  however the standard "point of care" rapid urine drug screen (uds) is set up not to detect dxm.    the half life of dxm is only 2-4 hours and its most common metabolites are another 4-6 hours.  2 days should be enough to clear it from the body.    lots of water and a diuretic will quickly decrease drug concentrations.  however many common drugs of abuse are lipophilic and hang around longer depending on how much body fat a person has.  the best way to pass a drug test is not to take drugs...