how long does morphine last

Morphine's pain relief effects typically last between 3 to 6 hours, depending on the formulation and method of administration. Injectable morphine begins working within 5-20 minutes, peaks around 60 minutes, and its effects last for about 3-4 hours. Oral morphine takes a bit longer to start but usually provides pain relief for about 4-6 hours. Extended-release forms of morphine can last anywhere from 12 to 24 hours per dose. The drug is mostly eliminated from the blood within about 10-15 hours, but traces can be detected for several days in urine and other tests.