How long does Flexeril stay in your system?

Answer 1

Flexeril (cyclobenzaprine) has an average elimination half-life of 18 hours. Half-life is the time required for half the quantity of a drug or other substance active in a living organism to be metabolized or eliminated by normal biological processes. This is however an approximation as there are several other factors that may play a role in it's elimination, such as the amount of Flexeril taken, your weight / body size, and your metabolism, among others. Wikipedia lists it's half-life as having a range of 8 to 37 hours. To sum up the answer I would say Flexeril would be in your system for no less than 24 hours and no longer than 3 to 4 days. The other thing to take into consideration is that there isn't a set moment in time in which the drug would no longer be present in your blood plasma levels. That is to say that the drug concentration declines gradually and eventually reaches a point in which the drug is still technically present in your bloodstream, but only in tiny trace amounts. Depending on the substance, most health care professionals may consider the substance to be completely eliminated at such small trace amounts.