Dextromethorphan (DXM) is a common cough suppressant found in many over-the-counter medications. The half-life of DXM is approximately 3 to 5 hours, but its metabolites can last longer in your system. After taking a dose, it usually takes about 24 hours for it to be significantly cleared from your system, but this can vary from person to person.
If you've taken 165 mg of DXM last night, it is generally advisable to wait at least 24 hours before


