How long does morphine ms contin (morphine) last in your blood?

Depends: specifically on the nature of the question. DUration of pain relief ... 12 hrs. ability to detect it on blood testing.... maybe 2-3 days ability to detect in urine testing 5-7 days.

MS Contin (morphine) in Blood: Hello. Most patients who take Morphine sulfate extended release form, do not take it just once daily. It's typically taken 2/day or even 3/day. Typically see it in blood a few days versus 4-5 days in urine BUT levels can linger around longer depending on how your body metabolizes morphine. If your body metabolizes it poorly, then it can linger for weeks!