Muscle relaxers generally start to work within 30 minutes to 1 hour after taking them. For example, cyclobenzaprine (Flexeril) often begins to provide relief in about 30 to 60 minutes, with peak effects occurring a few hours later. Methocarbamol also typically starts working within 30 minutes to an hour, reaching its peak effect in about 1 to 2 hours. Some muscle relaxers may take a couple of days to reach their full effect on muscle spasms, but initial muscle relaxation and pain relief usually occur within the first hour after dosing.

Timing of Effects by Muscle Relaxer Type

• Cyclobenzaprine (Flexeril): Effects start within 30 to 60 minutes; peak effect around 4 hours; full effects on muscle spasms may take up to 2 days.

• Methocarbamol: Starts working about 30 minutes after oral intake; peak effect in 1 to 2 hours.

• Baclofen: Starts working after about 1 hour, but dose adjustments over several days might be needed.

Additional Considerations

The exact time may vary depending on individual metabolism, dosage form (immediate vs extended-release), age, health conditions, and drug interactions. Muscle relaxers are usually prescribed for short-term relief of acute muscle spasms and pain.

In summary, muscle relaxers typically start working within 30 minutes to 1 hour, though full therapeutic effects may take longer, up to a few days in some cases, depending on the medication and individual circumstances.