Muscle relaxers generally start to work within 30 minutes to an hour after taking them. The pain relief and muscle relaxation effects typically peak between 1 to 3 hours after the dose. Depending on the specific muscle relaxer, the effects can last from about 4 to 24 hours. Here are some examples of common muscle relaxers and their onset times:
- Cyclobenzaprine (Flexeril): Effects begin around 30 minutes to an hour, with peak effectiveness in 4 to 8 hours; full effect on muscle spasm pain may take up to 7 days with continued use.
- Methocarbamol: Starts working in about 30 minutes, peaks at 1 to 2 hours, with effects lasting 4 to 6 hours.
- Carisoprodol: Takes about 30 minutes to start, peaks in 1 to 2 hours, lasting 4 to 6 hours.
- Tizanidine: Takes 1 to 2 hours to start, peak effect around 2 hours, lasting 4 to 6 hours.
- Baclofen: Begins effect about an hour after dosing; peak in 2 to 3 hours, lasting 4 to 8 hours.
The exact time may vary depending on individual metabolism, dosage, formulation (immediate vs extended release), and other factors. Muscle relaxers can cause drowsiness and should be used with caution regarding activities requiring alertness. In summary, most muscle relaxers start to work within 30 to 60 minutes, with peak effects in 1 to 3 hours.
