Codeine is typically detectable in urine for 24–48 hours after a single dose (up to 4 days for heavy users). In blood, codeine clears within 4–8 hours, though its active metabolite morphine is detectable for up to 12 hours. Hair follicle tests detect codeine for up to 90 days. Codeine metabolises to morphine and will trigger a positive opiate result on standard drug tests.
Estimates only. Individual results vary based on metabolism, body weight, hydration, and frequency of use.