how long does it take for flexeril to work

Flexeril (cyclobenzaprine) typically starts to work within 30 minutes to one hour after taking it, with muscle relaxant effects becoming noticeable. The full effect on muscle spasm pain may take up to 7 days of consistent use to be fully realized. Its duration of action is about 4 to 6 hours per dose. Extended-release formulations like Amrix may take longer, up to 4 days, to show full effects. Commonly, Flexeril is used for short-term relief, usually no longer than two to three weeks, because muscle spasms generally resolve in this timeframe. Side effects such as drowsiness can appear quickly as well, so caution is advised when performing activities requiring alertness.