Question: how long can cyclobenzaprine be detected?
Answer: The drug may be detectable in urine anywhere from 5 to 13 days after someone takes Flexeril. In blood, Flexeril may be detectable from 2 to 4 hours after someone uses it, and for up to 10 days. Flexeril may show up in a hair-based drug test for up to three days after someone uses it.