From the Research
Flexeril (cyclobenzaprine) typically begins to work within 1 hour after taking it, with most people experiencing some muscle relaxation effects within this timeframe, as evident from a study published in 2003 1. However, the full therapeutic effect may take several days of consistent use to develop. The medication reaches its maximum concentration in the bloodstream within 3-8 hours after ingestion. Flexeril works by acting on the central nervous system to reduce nerve impulses from the brain to skeletal muscles, thereby decreasing muscle spasms and associated pain. Some key points to consider when using Flexeril include:
- Onset of relief was apparent within 3 or 4 doses of the 5-mg regimen, as shown in the study 1.
- The standard dosage is usually 5-10 mg three times daily, with treatment typically lasting 2-3 weeks as prolonged use may lead to dependence.
- Side effects like drowsiness often appear before the full therapeutic benefit, so caution should be exercised when driving or operating machinery, especially when first starting the medication. It's also worth noting that while some relief may be felt quickly, patients should continue taking the medication as prescribed to maintain its effectiveness. A more recent study from 2022 2 found that cyclobenzaprine did not improve outcomes more than placebo in patients with acute low back pain, but this study had a different focus and population than the original study on Flexeril's onset of action 1. Overall, the evidence suggests that Flexeril can be an effective treatment for acute muscle spasms, but its use should be carefully considered and monitored due to potential side effects and the risk of dependence.