A certified Snap-N-Spike? Solution suitable for cyclobenzaprine testing methods by GC/MS or LC/MS for applications in pain prescription monitoring, forensic analysis, urine drug testing, or clinical toxicology. Also known as norcyclobenzaprine, N-desmethylcyclobenzaprine is the major urinary metabolite of the skeletal muscle relaxant cyclobenzaprine. Cyclobenzaprine, sold under trade names Flexeril?, Fexmid?, and Amrix?, is used to relieve skeletal muscle spasms and associated pain from acute musculoskeletal conditions.