The recommended starting methocarbamol dosage is 1500 mg (three 500-mg tablets or two 750-mg tablets) four times daily for the first two to three days of treatment. Then, the dose should be reduced to 1500 mg twice daily, 1000 mg four times daily, or 750 mg six times daily.s is always the case, do not adjust your dosage unless your healthcare provider specifically tells you to do so. Methocarbamol tablets come in two different strengths: 500 mg (generic only) and 750 mg.