When taking Flexeril, it starts working in your system in about an hour. The drug is active for about four to six hours, and after that your body begins eliminating it. The drug doesn’t have a direct effect on muscles, but instead works with the brain and spinal cord to calm muscle spasms. Some side effects of the medication include dry mouth and drowsiness. The latter can be dangerous when driving or operating machinery, especially if the dose is high enough to cause it.
How long does flexeril stay in your system can be determined by several factors, including the half-life of the drug and the type of drug test being conducted. Generally speaking, however, Cyclobenzaprine stays in the system for approximately 18 hours. It may remain detectable in urine for up to a week, but the drug is usually not detected by standard drug tests in workplaces because it is a prescription medication.
The drug can also be found in saliva, but this detection window is very short. It only lasts for about a day or two, and it depends on the dosage and frequency of usage. Despite this, many workplaces do use saliva tests as they are considered the least invasive of all testing options.
Finally, Flexeril can be traced in hair samples for up to 90 days because the drug becomes entrapped in the follicles as it is being eliminated from the body. These tests are rarely used as they are more invasive than others and are expensive to conduct.